Merge remote-tracking branch 'origin/master' into features/actor-lineage

CONTRIBUTING.md

@@ -36,7 +36,7 @@ Members of the Apple FoundationDB team are part of the core committers helping r
 
 ## Contributing
 ### Opening a Pull Request
-We love pull requests! For minor changes, feel free to open up a PR directly. For larger feature development and any changes that may require community discussion, we ask that you discuss your ideas on the [community forums](https://forums.foundationdb.org) prior to opening a PR, and then reference that thread within your PR comment.
+We love pull requests! For minor changes, feel free to open up a PR directly. For larger feature development and any changes that may require community discussion, we ask that you discuss your ideas on the [community forums](https://forums.foundationdb.org) prior to opening a PR, and then reference that thread within your PR comment. Please refer to [FoundationDB Commit Process](https://github.com/apple/foundationdb/wiki/FoundationDB-Commit-Process) for more detailed guidelines.
 
 CI will be run automatically for core committers, and for community PRs it will be initiated by the request of a core committer.  Tests can also be run locally via `ctest`, and core committers can run additional validation on pull requests prior to merging them.
 

bindings/c/fdb_c.cpp

@@ -364,6 +364,17 @@ extern "C" DLLEXPORT double fdb_database_get_main_thread_busyness(FDBDatabase* d
 	return DB(d)->getMainThreadBusyness();
 }
 
+// Returns the protocol version reported by a quorum of coordinators
+// If an expected version is non-zero, the future won't return until the protocol version is different than expected
+extern "C" DLLEXPORT FDBFuture* fdb_database_get_server_protocol(FDBDatabase* db, uint64_t expected_version) {
+	Optional<ProtocolVersion> expected;
+	if (expected_version > 0) {
+		expected = ProtocolVersion(expected_version);
+	}
+
+	return (FDBFuture*)(DB(db)->getServerProtocol(expected).extractPtr());
+}
+
 extern "C" DLLEXPORT void fdb_transaction_destroy(FDBTransaction* tr) {
 	try {
 		TXN(tr)->delref();
@@ -583,10 +594,6 @@ extern "C" DLLEXPORT FDBFuture* fdb_transaction_get_approximate_size(FDBTransact
 	return (FDBFuture*)TXN(tr)->getApproximateSize().extractPtr();
 }
 
-extern "C" DLLEXPORT FDBFuture* fdb_get_server_protocol(const char* clusterFilePath) {
-	return (FDBFuture*)(API->getServerProtocol(clusterFilePath ? clusterFilePath : "").extractPtr());
-}
-
 extern "C" DLLEXPORT FDBFuture* fdb_transaction_get_versionstamp(FDBTransaction* tr) {
 	return (FDBFuture*)(TXN(tr)->getVersionstamp().extractPtr());
 }

bindings/c/foundationdb/fdb_c.h

@@ -189,6 +189,8 @@ DLLEXPORT WARN_UNUSED_RESULT FDBFuture* fdb_database_create_snapshot(FDBDatabase
 
 DLLEXPORT WARN_UNUSED_RESULT double fdb_database_get_main_thread_busyness(FDBDatabase* db);
 
+DLLEXPORT WARN_UNUSED_RESULT FDBFuture* fdb_database_get_server_protocol(FDBDatabase* db, uint64_t expected_version);
+
 DLLEXPORT void fdb_transaction_destroy(FDBTransaction* tr);
 
 DLLEXPORT void fdb_transaction_cancel(FDBTransaction* tr);
@@ -281,8 +283,6 @@ DLLEXPORT WARN_UNUSED_RESULT fdb_error_t fdb_transaction_get_committed_version(F
  */
 DLLEXPORT WARN_UNUSED_RESULT FDBFuture* fdb_transaction_get_approximate_size(FDBTransaction* tr);
 
-DLLEXPORT WARN_UNUSED_RESULT FDBFuture* fdb_get_server_protocol(const char* clusterFilePath);
-
 DLLEXPORT WARN_UNUSED_RESULT FDBFuture* fdb_transaction_get_versionstamp(FDBTransaction* tr);
 
 DLLEXPORT WARN_UNUSED_RESULT FDBFuture* fdb_transaction_on_error(FDBTransaction* tr, fdb_error_t error);

bindings/c/test/unit/unit_tests.cpp

@@ -1513,17 +1513,17 @@ TEST_CASE("fdb_transaction_get_approximate_size") {
 	}
 }
 
-TEST_CASE("fdb_get_server_protocol") {
+TEST_CASE("fdb_database_get_server_protocol") {
 	// We don't really have any expectations other than "don't crash" here
-	FDBFuture* protocolFuture = fdb_get_server_protocol(clusterFilePath.c_str());
+	FDBFuture* protocolFuture = fdb_database_get_server_protocol(db, 0);
 	uint64_t out;
 
 	fdb_check(fdb_future_block_until_ready(protocolFuture));
 	fdb_check(fdb_future_get_uint64(protocolFuture, &out));
 	fdb_future_destroy(protocolFuture);
 
-	// "Default" cluster file version
-	protocolFuture = fdb_get_server_protocol(nullptr);
+	// Passing in an expected version that's different than the cluster version
+	protocolFuture = fdb_database_get_server_protocol(db, 0x0FDB00A200090000LL);
 	fdb_check(fdb_future_block_until_ready(protocolFuture));
 	fdb_check(fdb_future_get_uint64(protocolFuture, &out));
 	fdb_future_destroy(protocolFuture);

bindings/python/fdb/__init__.py

@@ -95,7 +95,6 @@ def api_version(ver):
         'transactional',
         'options',
         'StreamingMode',
-        'get_server_protocol'
     )
 
     _add_symbols(fdb.impl, list)

bindings/python/fdb/impl.py

@@ -1531,9 +1531,6 @@ def init_c_api():
     _capi.fdb_transaction_get_approximate_size.argtypes = [ctypes.c_void_p]
     _capi.fdb_transaction_get_approximate_size.restype = ctypes.c_void_p
 
-    _capi.fdb_get_server_protocol.argtypes = [ctypes.c_char_p]
-    _capi.fdb_get_server_protocol.restype = ctypes.c_void_p
-
     _capi.fdb_transaction_get_versionstamp.argtypes = [ctypes.c_void_p]
     _capi.fdb_transaction_get_versionstamp.restype = ctypes.c_void_p
 
@@ -1733,13 +1730,6 @@ open_databases = {}
 
 cacheLock = threading.Lock()
 
-def get_server_protocol(clusterFilePath=None):
-    with _network_thread_reentrant_lock:
-        if not _network_thread:
-            init()
-
-    return FutureUInt64(_capi.fdb_get_server_protocol(optionalParamToBytes(clusterFilePath)[0]))
-
 def open(cluster_file=None, event_model=None):
     """Opens the given database (or the default database of the cluster indicated
     by the fdb.cluster file in a platform-specific location, if no cluster_file

build/docker/centos6/devel/Dockerfile

@@ -76,4 +76,9 @@ RUN rm -f /root/anaconda-ks.cfg && \
     '   j start --tarball $(find ${HOME}/build_output/packages -name correctness\*.tar.gz) "${@}"' \
     '}' \
     '' \
-    >> .bashrc
+    'USER_BASHRC="$HOME/src/.bashrc.local"' \
+    'if test -f "$USER_BASHRC"; then' \
+    '   source $USER_BASHRC' \
+    'fi' \
+    '' \
+    >> .bashrc

build/docker/centos7/devel/Dockerfile

@@ -104,5 +104,10 @@ RUN rm -f /root/anaconda-ks.cfg && \
     '   j start --tarball $(find ${HOME}/build_output/packages -name correctness\*.tar.gz) "${@}"' \
     '}' \
     '' \
+    'USER_BASHRC="$HOME/src/.bashrc.local"' \
+    'if test -f "$USER_BASHRC"; then' \
+    '   source $USER_BASHRC' \
+    'fi' \
+    '' \
     'bash ${HOME}/docker_proxy.sh' \
-    >> .bashrc
+    >> .bashrc

fdbcli/fdbcli.actor.cpp

@@ -24,6 +24,7 @@
 #include "fdbclient/Status.h"
 #include "fdbclient/StatusClient.h"
 #include "fdbclient/DatabaseContext.h"
+#include "fdbclient/GlobalConfig.actor.h"
 #include "fdbclient/NativeAPI.actor.h"
 #include "fdbclient/ReadYourWrites.h"
 #include "fdbclient/ClusterInterface.h"
@@ -3841,25 +3842,16 @@ ACTOR Future<int> cli(CLIOptions opt, LineNoise* plinenoise) {
 								is_error = true;
 								continue;
 							}
-							state Future<Optional<Standalone<StringRef>>> sampleRateFuture =
-							    tr->get(fdbClientInfoTxnSampleRate);
-							state Future<Optional<Standalone<StringRef>>> sizeLimitFuture =
-							    tr->get(fdbClientInfoTxnSizeLimit);
-							wait(makeInterruptable(success(sampleRateFuture) && success(sizeLimitFuture)));
+							const double sampleRateDbl = GlobalConfig::globalConfig().get<double>(
+							    fdbClientInfoTxnSampleRate, std::numeric_limits<double>::infinity());
+							const int64_t sizeLimit =
+							    GlobalConfig::globalConfig().get<int64_t>(fdbClientInfoTxnSizeLimit, -1);
 							std::string sampleRateStr = "default", sizeLimitStr = "default";
-							if (sampleRateFuture.get().present()) {
-								const double sampleRateDbl =
-								    BinaryReader::fromStringRef<double>(sampleRateFuture.get().get(), Unversioned());
-								if (!std::isinf(sampleRateDbl)) {
-									sampleRateStr = boost::lexical_cast<std::string>(sampleRateDbl);
-								}
+							if (!std::isinf(sampleRateDbl)) {
+								sampleRateStr = boost::lexical_cast<std::string>(sampleRateDbl);
 							}
-							if (sizeLimitFuture.get().present()) {
-								const int64_t sizeLimit =
-								    BinaryReader::fromStringRef<int64_t>(sizeLimitFuture.get().get(), Unversioned());
-								if (sizeLimit != -1) {
-									sizeLimitStr = boost::lexical_cast<std::string>(sizeLimit);
-								}
+							if (sizeLimit != -1) {
+								sizeLimitStr = boost::lexical_cast<std::string>(sizeLimit);
 							}
 							printf("Client profiling rate is set to %s and size limit is set to %s.\n",
 							       sampleRateStr.c_str(),
@@ -3897,8 +3889,12 @@ ACTOR Future<int> cli(CLIOptions opt, LineNoise* plinenoise) {
 									continue;
 								}
 							}
-							tr->set(fdbClientInfoTxnSampleRate, BinaryWriter::toValue(sampleRate, Unversioned()));
-							tr->set(fdbClientInfoTxnSizeLimit, BinaryWriter::toValue(sizeLimit, Unversioned()));
+
+							Tuple rate = Tuple().appendDouble(sampleRate);
+							Tuple size = Tuple().append(sizeLimit);
+							tr->setOption(FDBTransactionOptions::SPECIAL_KEY_SPACE_ENABLE_WRITES);
+							tr->set(GlobalConfig::prefixedKey(fdbClientInfoTxnSampleRate), rate.pack());
+							tr->set(GlobalConfig::prefixedKey(fdbClientInfoTxnSizeLimit), size.pack());
 							if (!intrans) {
 								wait(commitTransaction(tr));
 							}

fdbclient/CMakeLists.txt

@@ -31,6 +31,9 @@ set(FDBCLIENT_SRCS
   FDBOptions.h
   FDBTypes.h
   FileBackupAgent.actor.cpp
+  GlobalConfig.h
+  GlobalConfig.actor.h
+  GlobalConfig.actor.cpp
   GrvProxyInterface.h
   HTTP.actor.cpp
   IClientApi.h

fdbclient/CommitProxyInterface.h

@@ -31,6 +31,7 @@
 #include "fdbclient/CommitTransaction.h"
 #include "fdbserver/RatekeeperInterface.h"
 #include "fdbclient/TagThrottle.h"
+#include "fdbclient/GlobalConfig.h"
 
 #include "fdbrpc/Stats.h"
 #include "fdbrpc/TimedRequest.h"
@@ -113,16 +114,10 @@ struct ClientDBInfo {
 	vector<CommitProxyInterface> commitProxies;
 	Optional<CommitProxyInterface>
 	    firstCommitProxy; // not serialized, used for commitOnFirstProxy when the commit proxies vector has been shrunk
-	double clientTxnInfoSampleRate;
-	int64_t clientTxnInfoSizeLimit;
 	Optional<Value> forward;
-	double transactionTagSampleRate;
-	double transactionTagSampleCost;
+	vector<VersionHistory> history;
 
-	ClientDBInfo()
-	  : clientTxnInfoSampleRate(std::numeric_limits<double>::infinity()), clientTxnInfoSizeLimit(-1),
-	    transactionTagSampleRate(CLIENT_KNOBS->READ_TAG_SAMPLE_RATE),
-	    transactionTagSampleCost(CLIENT_KNOBS->COMMIT_SAMPLE_COST) {}
+	ClientDBInfo() {}
 
 	bool operator==(ClientDBInfo const& r) const { return id == r.id; }
 	bool operator!=(ClientDBInfo const& r) const { return id != r.id; }
@@ -132,15 +127,7 @@ struct ClientDBInfo {
 		if constexpr (!is_fb_function<Archive>) {
 			ASSERT(ar.protocolVersion().isValid());
 		}
-		serializer(ar,
-		           grvProxies,
-		           commitProxies,
-		           id,
-		           clientTxnInfoSampleRate,
-		           clientTxnInfoSizeLimit,
-		           forward,
-		           transactionTagSampleRate,
-		           transactionTagSampleCost);
+		serializer(ar, grvProxies, commitProxies, id, forward, history);
 	}
 };
 

fdbclient/GlobalConfig.actor.cpp

@@ -0,0 +1,229 @@
+/*
+ * GlobalConfig.actor.cpp
+ *
+ * This source file is part of the FoundationDB open source project
+ *
+ * Copyright 2013-2021 Apple Inc. and the FoundationDB project authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "fdbclient/DatabaseContext.h"
+#include "fdbclient/GlobalConfig.actor.h"
+#include "fdbclient/SpecialKeySpace.actor.h"
+#include "fdbclient/SystemData.h"
+#include "fdbclient/Tuple.h"
+#include "flow/flow.h"
+#include "flow/genericactors.actor.h"
+
+#include "flow/actorcompiler.h" // This must be the last #include.
+
+const KeyRef fdbClientInfoTxnSampleRate = LiteralStringRef("config/fdb_client_info/client_txn_sample_rate");
+const KeyRef fdbClientInfoTxnSizeLimit = LiteralStringRef("config/fdb_client_info/client_txn_size_limit");
+
+const KeyRef transactionTagSampleRate = LiteralStringRef("config/transaction_tag_sample_rate");
+const KeyRef transactionTagSampleCost = LiteralStringRef("config/transaction_tag_sample_cost");
+
+GlobalConfig::GlobalConfig() : lastUpdate(0) {}
+
+void GlobalConfig::create(DatabaseContext* cx, Reference<AsyncVar<ClientDBInfo>> dbInfo) {
+	if (g_network->global(INetwork::enGlobalConfig) == nullptr) {
+		auto config = new GlobalConfig{};
+		config->cx = Database(cx);
+		g_network->setGlobal(INetwork::enGlobalConfig, config);
+		config->_updater = updater(config, dbInfo);
+	}
+}
+
+GlobalConfig& GlobalConfig::globalConfig() {
+	void* res = g_network->global(INetwork::enGlobalConfig);
+	ASSERT(res);
+	return *reinterpret_cast<GlobalConfig*>(res);
+}
+
+Key GlobalConfig::prefixedKey(KeyRef key) {
+	return key.withPrefix(SpecialKeySpace::getModuleRange(SpecialKeySpace::MODULE::GLOBALCONFIG).begin);
+}
+
+const Reference<ConfigValue> GlobalConfig::get(KeyRef name) {
+	auto it = data.find(name);
+	if (it == data.end()) {
+		return Reference<ConfigValue>();
+	}
+	return it->second;
+}
+
+const std::map<KeyRef, Reference<ConfigValue>> GlobalConfig::get(KeyRangeRef range) {
+	std::map<KeyRef, Reference<ConfigValue>> results;
+	for (const auto& [key, value] : data) {
+		if (range.contains(key)) {
+			results[key] = value;
+		}
+	}
+	return results;
+}
+
+Future<Void> GlobalConfig::onInitialized() {
+	return initialized.getFuture();
+}
+
+void GlobalConfig::insert(KeyRef key, ValueRef value) {
+	data.erase(key);
+
+	Arena arena(key.expectedSize() + value.expectedSize());
+	KeyRef stableKey = KeyRef(arena, key);
+	try {
+		std::any any;
+		Tuple t = Tuple::unpack(value);
+		if (t.getType(0) == Tuple::ElementType::UTF8) {
+			any = StringRef(arena, t.getString(0).contents());
+		} else if (t.getType(0) == Tuple::ElementType::INT) {
+			any = t.getInt(0);
+		} else if (t.getType(0) == Tuple::ElementType::FLOAT) {
+			any = t.getFloat(0);
+		} else if (t.getType(0) == Tuple::ElementType::DOUBLE) {
+			any = t.getDouble(0);
+		} else {
+			ASSERT(false);
+		}
+		data[stableKey] = makeReference<ConfigValue>(std::move(arena), std::move(any));
+	} catch (Error& e) {
+		TraceEvent("GlobalConfigTupleParseError").detail("What", e.what());
+	}
+}
+
+void GlobalConfig::erase(KeyRef key) {
+	data.erase(key);
+}
+
+void GlobalConfig::erase(KeyRangeRef range) {
+	auto it = data.begin();
+	while (it != data.end()) {
+		if (range.contains(it->first)) {
+			it = data.erase(it);
+		} else {
+			++it;
+		}
+	}
+}
+
+// Older FDB versions used different keys for client profiling data. This
+// function performs a one-time migration of data in these keys to the new
+// global configuration key space.
+ACTOR Future<Void> GlobalConfig::migrate(GlobalConfig* self) {
+	state Reference<ReadYourWritesTransaction> tr = makeReference<ReadYourWritesTransaction>(self->cx);
+	tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
+
+	state Key migratedKey("\xff\x02/fdbClientInfo/migrated/"_sr);
+	state Optional<Value> migrated = wait(tr->get(migratedKey));
+	if (migrated.present()) {
+		// Already performed migration.
+		return Void();
+	}
+
+	state Optional<Value> sampleRate = wait(tr->get(Key("\xff\x02/fdbClientInfo/client_txn_sample_rate/"_sr)));
+	state Optional<Value> sizeLimit = wait(tr->get(Key("\xff\x02/fdbClientInfo/client_txn_size_limit/"_sr)));
+
+	loop {
+		try {
+			tr->setOption(FDBTransactionOptions::SPECIAL_KEY_SPACE_ENABLE_WRITES);
+			// The value doesn't matter too much, as long as the key is set.
+			tr->set(migratedKey.contents(), "1"_sr);
+			if (sampleRate.present()) {
+				const double sampleRateDbl =
+				    BinaryReader::fromStringRef<double>(sampleRate.get().contents(), Unversioned());
+				Tuple rate = Tuple().appendDouble(sampleRateDbl);
+				tr->set(GlobalConfig::prefixedKey(fdbClientInfoTxnSampleRate), rate.pack());
+			}
+			if (sizeLimit.present()) {
+				const int64_t sizeLimitInt =
+				    BinaryReader::fromStringRef<int64_t>(sizeLimit.get().contents(), Unversioned());
+				Tuple size = Tuple().append(sizeLimitInt);
+				tr->set(GlobalConfig::prefixedKey(fdbClientInfoTxnSizeLimit), size.pack());
+			}
+
+			wait(tr->commit());
+			return Void();
+		} catch (Error& e) {
+			throw;
+		}
+	}
+}
+
+// Updates local copy of global configuration by reading the entire key-range
+// from storage.
+ACTOR Future<Void> GlobalConfig::refresh(GlobalConfig* self) {
+	self->data.clear();
+
+	Transaction tr(self->cx);
+	Standalone<RangeResultRef> result = wait(tr.getRange(globalConfigDataKeys, CLIENT_KNOBS->TOO_MANY));
+	for (const auto& kv : result) {
+		KeyRef systemKey = kv.key.removePrefix(globalConfigKeysPrefix);
+		self->insert(systemKey, kv.value);
+	}
+	return Void();
+}
+
+// Applies updates to the local copy of the global configuration when this
+// process receives an updated history.
+ACTOR Future<Void> GlobalConfig::updater(GlobalConfig* self, Reference<AsyncVar<ClientDBInfo>> dbInfo) {
+	wait(self->migrate(self));
+
+	wait(self->refresh(self));
+	self->initialized.send(Void());
+
+	loop {
+		try {
+			wait(dbInfo->onChange());
+
+			auto& history = dbInfo->get().history;
+			if (history.size() == 0) {
+				continue;
+			}
+
+			if (self->lastUpdate < history[0].version) {
+				// This process missed too many global configuration
+				// history updates or the protocol version changed, so it
+				// must re-read the entire configuration range.
+				wait(self->refresh(self));
+				if (dbInfo->get().history.size() > 0) {
+					self->lastUpdate = dbInfo->get().history.back().version;
+				}
+			} else {
+				// Apply history in order, from lowest version to highest
+				// version. Mutation history should already be stored in
+				// ascending version order.
+				for (const auto& vh : history) {
+					if (vh.version <= self->lastUpdate) {
+						continue; // already applied this mutation
+					}
+
+					for (const auto& mutation : vh.mutations.contents()) {
+						if (mutation.type == MutationRef::SetValue) {
+							self->insert(mutation.param1, mutation.param2);
+						} else if (mutation.type == MutationRef::ClearRange) {
+							self->erase(KeyRangeRef(mutation.param1, mutation.param2));
+						} else {
+							ASSERT(false);
+						}
+					}
+
+					ASSERT(vh.version > self->lastUpdate);
+					self->lastUpdate = vh.version;
+				}
+			}
+		} catch (Error& e) {
+			throw;
+		}
+	}
+}

fdbclient/GlobalConfig.actor.h

@@ -0,0 +1,146 @@
+/*
+ * GlobalConfig.actor.h
+ *
+ * This source file is part of the FoundationDB open source project
+ *
+ * Copyright 2013-2021 Apple Inc. and the FoundationDB project authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#if defined(NO_INTELLISENSE) && !defined(FDBCLIENT_GLOBALCONFIG_ACTOR_G_H)
+#define FDBCLIENT_GLOBALCONFIG_ACTOR_G_H
+#include "fdbclient/GlobalConfig.actor.g.h"
+#elif !defined(FDBCLIENT_GLOBALCONFIG_ACTOR_H)
+#define FDBCLIENT_GLOBALCONFIG_ACTOR_H
+
+#include <any>
+#include <map>
+#include <type_traits>
+#include <unordered_map>
+
+#include "fdbclient/CommitProxyInterface.h"
+#include "fdbclient/GlobalConfig.h"
+#include "fdbclient/ReadYourWrites.h"
+
+#include "flow/actorcompiler.h" // has to be last include
+
+// The global configuration is a series of typed key-value pairs synced to all
+// nodes (server and client) in an FDB cluster in an eventually consistent
+// manner. Only small key-value pairs should be stored in global configuration;
+// an excessive amount of data can cause synchronization slowness.
+
+// Keys
+extern const KeyRef fdbClientInfoTxnSampleRate;
+extern const KeyRef fdbClientInfoTxnSizeLimit;
+
+extern const KeyRef transactionTagSampleRate;
+extern const KeyRef transactionTagSampleCost;
+
+// Structure used to hold the values stored by global configuration. The arena
+// is used as memory to store both the key and the value (the value is only
+// stored in the arena if it is an object; primitives are just copied).
+struct ConfigValue : ReferenceCounted<ConfigValue> {
+	Arena arena;
+	std::any value;
+
+	ConfigValue() {}
+	ConfigValue(Arena&& a, std::any&& v) : arena(a), value(v) {}
+};
+
+class GlobalConfig : NonCopyable {
+public:
+	// Creates a GlobalConfig singleton, accessed by calling GlobalConfig().
+	// This function should only be called once by each process (however, it is
+	// idempotent and calling it multiple times will have no effect).
+	static void create(DatabaseContext* cx, Reference<AsyncVar<ClientDBInfo>> dbInfo);
+
+	// Returns a reference to the global GlobalConfig object. Clients should
+	// call this function whenever they need to read a value out of the global
+	// configuration.
+	static GlobalConfig& globalConfig();
+
+	// Use this function to turn a global configuration key defined above into
+	// the full path needed to set the value in the database.
+	//
+	// For example, given "config/a", returns "\xff\xff/global_config/config/a".
+	static Key prefixedKey(KeyRef key);
+
+	// Get a value from the framework. Values are returned as a ConfigValue
+	// reference which also contains the arena holding the object. As long as
+	// the caller keeps the ConfigValue reference, the value is guaranteed to
+	// be readable. An empty reference is returned if the value does not exist.
+	const Reference<ConfigValue> get(KeyRef name);
+	const std::map<KeyRef, Reference<ConfigValue>> get(KeyRangeRef range);
+
+	// For arithmetic value types, returns a copy of the value for the given
+	// key, or the supplied default value if the framework does not know about
+	// the key.
+	template <typename T, typename std::enable_if<std::is_arithmetic<T>{}, bool>::type = true>
+	const T get(KeyRef name, T defaultVal) {
+		try {
+			auto configValue = get(name);
+			if (configValue.isValid()) {
+				if (configValue->value.has_value()) {
+					return std::any_cast<T>(configValue->value);
+				}
+			}
+
+			return defaultVal;
+		} catch (Error& e) {
+			throw;
+		}
+	}
+
+	// Trying to write into the global configuration keyspace? To write data,
+	// submit a transaction to \xff\xff/global_config/<your-key> with
+	// <your-value> encoded using the FDB tuple typecodes. Use the helper
+	// function `prefixedKey` to correctly prefix your global configuration
+	// key.
+
+	// Triggers the returned future when the global configuration singleton has
+	// been created and is ready.
+	Future<Void> onInitialized();
+
+private:
+	GlobalConfig();
+
+	// The functions below only affect the local copy of the global
+	// configuration keyspace! To insert or remove values across all nodes you
+	// must use a transaction (see the note above).
+
+	// Inserts the given key-value pair into the local copy of the global
+	// configuration keyspace, overwriting the old key-value pair if it exists.
+	// `value` must be encoded using the FDB tuple typecodes.
+	void insert(KeyRef key, ValueRef value);
+	// Removes the given key (and associated value) from the local copy of the
+	// global configuration keyspace.
+	void erase(KeyRef key);
+	// Removes the given key range (and associated values) from the local copy
+	// of the global configuration keyspace.
+	void erase(KeyRangeRef range);
+
+	ACTOR static Future<Void> migrate(GlobalConfig* self);
+	ACTOR static Future<Void> refresh(GlobalConfig* self);
+	ACTOR static Future<Void> updater(GlobalConfig* self, Reference<AsyncVar<ClientDBInfo>> dbInfo);
+
+	Database cx;
+	Future<Void> _updater;
+	Promise<Void> initialized;
+	std::unordered_map<StringRef, Reference<ConfigValue>> data;
+	Version lastUpdate;
+};
+
+#endif

fdbclient/GlobalConfig.h

@@ -0,0 +1,45 @@
+/*
+ * GlobalConfig.h
+ *
+ * This source file is part of the FoundationDB open source project
+ *
+ * Copyright 2013-2021 Apple Inc. and the FoundationDB project authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include "fdbclient/CommitTransaction.h"
+#include "fdbclient/FDBTypes.h"
+
+// Used to store a list of mutations made to the global configuration at a
+// specific version.
+struct VersionHistory {
+	constexpr static FileIdentifier file_identifier = 5863456;
+
+	VersionHistory() {}
+	VersionHistory(Version v) : version(v) {}
+
+	Version version;
+	Standalone<VectorRef<MutationRef>> mutations;
+
+	bool operator<(const VersionHistory& other) const { return version < other.version; }
+
+	int expectedSize() const { return sizeof(version) + mutations.expectedSize(); }
+
+	template <typename Ar>
+	void serialize(Ar& ar) {
+		serializer(ar, mutations, version);
+	}
+};

fdbclient/IClientApi.h

@@ -28,6 +28,7 @@
 
 #include "flow/ThreadHelper.actor.h"
 
+// An interface that represents a transaction created by a client
 class ITransaction {
 public:
 	virtual ~ITransaction() {}
@@ -90,6 +91,7 @@ public:
 	virtual void delref() = 0;
 };
 
+// An interface that represents a connection to a cluster made by a client
 class IDatabase {
 public:
 	virtual ~IDatabase() {}
@@ -98,6 +100,11 @@ public:
 	virtual void setOption(FDBDatabaseOptions::Option option, Optional<StringRef> value = Optional<StringRef>()) = 0;
 	virtual double getMainThreadBusyness() = 0;
 
+	// Returns the protocol version reported by a quorum of coordinators
+	// If an expected version is given, the future won't return until the protocol version is different than expected
+	virtual ThreadFuture<ProtocolVersion> getServerProtocol(
+	    Optional<ProtocolVersion> expectedVersion = Optional<ProtocolVersion>()) = 0;
+
 	virtual void addref() = 0;
 	virtual void delref() = 0;
 
@@ -110,13 +117,16 @@ public:
 	virtual ThreadFuture<Void> createSnapshot(const StringRef& uid, const StringRef& snapshot_command) = 0;
 };
 
+// An interface that presents the top-level FDB client API as exposed through the C bindings
+//
+// This interface and its associated objects are intended to live outside the network thread, so its asynchronous
+// operations use ThreadFutures and implementations should be thread safe.
 class IClientApi {
 public:
 	virtual ~IClientApi() {}
 
 	virtual void selectApiVersion(int apiVersion) = 0;
 	virtual const char* getClientVersion() = 0;
-	virtual ThreadFuture<uint64_t> getServerProtocol(const char* clusterFilePath) = 0;
 
 	virtual void setNetworkOption(FDBNetworkOptions::Option option,
 	                              Optional<StringRef> value = Optional<StringRef>()) = 0;

fdbclient/MultiVersionTransaction.actor.cpp

@@ -356,7 +356,32 @@ double DLDatabase::getMainThreadBusyness() {
 	return 0;
 }
 
+// Returns the protocol version reported by a quorum of coordinators
+// If an expected version is given, the future won't return until the protocol version is different than expected
+ThreadFuture<ProtocolVersion> DLDatabase::getServerProtocol(Optional<ProtocolVersion> expectedVersion) {
+	ASSERT(api->databaseGetServerProtocol != nullptr);
+
+	uint64_t expected =
+	    expectedVersion.map<uint64_t>([](const ProtocolVersion& v) { return v.version(); }).orDefault(0);
+	FdbCApi::FDBFuture* f = api->databaseGetServerProtocol(db, expected);
+	return toThreadFuture<ProtocolVersion>(api, f, [](FdbCApi::FDBFuture* f, FdbCApi* api) {
+		uint64_t pv;
+		FdbCApi::fdb_error_t error = api->futureGetUInt64(f, &pv);
+		ASSERT(!error);
+		return ProtocolVersion(pv);
+	});
+}
+
 // DLApi
+
+// Loads the specified function from a dynamic library
+//
+// fp - The function pointer where the loaded function will be stored
+// lib - The dynamic library where the function is loaded from
+// libPath - The path of the dynamic library (used for logging)
+// functionName - The function to load
+// requireFunction - Determines the behavior if the function is not present. If true, an error is thrown. If false,
+//                   the function pointer will be set to nullptr.
 template <class T>
 void loadClientFunction(T* fp, void* lib, std::string libPath, const char* functionName, bool requireFunction = true) {
 	*(void**)(fp) = loadFunction(lib, functionName);
@@ -403,6 +428,8 @@ void DLApi::init() {
 	                   fdbCPath,
 	                   "fdb_database_get_main_thread_busyness",
 	                   headerVersion >= 700);
+	loadClientFunction(
+	    &api->databaseGetServerProtocol, lib, fdbCPath, "fdb_database_get_server_protocol", headerVersion >= 700);
 	loadClientFunction(&api->databaseDestroy, lib, fdbCPath, "fdb_database_destroy");
 	loadClientFunction(&api->databaseRebootWorker, lib, fdbCPath, "fdb_database_reboot_worker", headerVersion >= 700);
 	loadClientFunction(&api->databaseForceRecoveryWithDataLoss,
@@ -452,7 +479,7 @@ void DLApi::init() {
 
 	loadClientFunction(
 	    &api->futureGetInt64, lib, fdbCPath, headerVersion >= 620 ? "fdb_future_get_int64" : "fdb_future_get_version");
-	loadClientFunction(&api->futureGetUInt64, lib, fdbCPath, "fdb_future_get_uint64");
+	loadClientFunction(&api->futureGetUInt64, lib, fdbCPath, "fdb_future_get_uint64", headerVersion >= 700);
 	loadClientFunction(&api->futureGetError, lib, fdbCPath, "fdb_future_get_error");
 	loadClientFunction(&api->futureGetKey, lib, fdbCPath, "fdb_future_get_key");
 	loadClientFunction(&api->futureGetValue, lib, fdbCPath, "fdb_future_get_value");
@@ -488,11 +515,6 @@ const char* DLApi::getClientVersion() {
 	return api->getClientVersion();
 }
 
-ThreadFuture<uint64_t> DLApi::getServerProtocol(const char* clusterFilePath) {
-	ASSERT(false);
-	return ThreadFuture<uint64_t>();
-}
-
 void DLApi::setNetworkOption(FDBNetworkOptions::Option option, Optional<StringRef> value) {
 	throwIfError(api->setNetworkOption(
 	    option, value.present() ? value.get().begin() : nullptr, value.present() ? value.get().size() : 0));
@@ -856,7 +878,7 @@ MultiVersionDatabase::MultiVersionDatabase(MultiVersionApi* api,
                                            std::string clusterFilePath,
                                            Reference<IDatabase> db,
                                            bool openConnectors)
-  : dbState(new DatabaseState()) {
+  : dbState(new DatabaseState()), clusterFilePath(clusterFilePath) {
 	dbState->db = db;
 	dbState->dbVar->set(db);
 
@@ -941,6 +963,15 @@ double MultiVersionDatabase::getMainThreadBusyness() {
 	return 0;
 }
 
+// Returns the protocol version reported by a quorum of coordinators
+// If an expected version is given, the future won't return until the protocol version is different than expected
+ThreadFuture<ProtocolVersion> MultiVersionDatabase::getServerProtocol(Optional<ProtocolVersion> expectedVersion) {
+	// TODO: send this out through the active database
+	return MultiVersionApi::api->getLocalClient()
+	    ->api->createDatabase(clusterFilePath.c_str())
+	    ->getServerProtocol(expectedVersion);
+}
+
 void MultiVersionDatabase::Connector::connect() {
 	addref();
 	onMainThreadVoid(
@@ -1181,10 +1212,6 @@ const char* MultiVersionApi::getClientVersion() {
 	return localClient->api->getClientVersion();
 }
 
-ThreadFuture<uint64_t> MultiVersionApi::getServerProtocol(const char* clusterFilePath) {
-	return api->localClient->api->getServerProtocol(clusterFilePath);
-}
-
 void validateOption(Optional<StringRef> value, bool canBePresent, bool canBeAbsent, bool canBeEmpty = true) {
 	ASSERT(canBePresent || canBeAbsent);
 

fdbclient/MultiVersionTransaction.h

@@ -28,6 +28,8 @@
 
 #include "flow/ThreadHelper.actor.h"
 
+// FdbCApi is used as a wrapper around the FoundationDB C API that gets loaded from an external client library.
+// All of the required functions loaded from that external library are stored in function pointers in this struct.
 struct FdbCApi : public ThreadSafeReferenceCounted<FdbCApi> {
 	typedef struct future FDBFuture;
 	typedef struct cluster FDBCluster;
@@ -55,7 +57,6 @@ struct FdbCApi : public ThreadSafeReferenceCounted<FdbCApi> {
 	// Network
 	fdb_error_t (*selectApiVersion)(int runtimeVersion, int headerVersion);
 	const char* (*getClientVersion)();
-	FDBFuture* (*getServerProtocol)(const char* clusterFilePath);
 	fdb_error_t (*setNetworkOption)(FDBNetworkOptions::Option option, uint8_t const* value, int valueLength);
 	fdb_error_t (*setupNetwork)();
 	fdb_error_t (*runNetwork)();
@@ -81,6 +82,7 @@ struct FdbCApi : public ThreadSafeReferenceCounted<FdbCApi> {
 	                                     uint8_t const* snapshotCommmand,
 	                                     int snapshotCommandLength);
 	double (*databaseGetMainThreadBusyness)(FDBDatabase* database);
+	FDBFuture* (*databaseGetServerProtocol)(FDBDatabase* database, uint64_t expectedVersion);
 
 	// Transaction
 	fdb_error_t (*transactionSetOption)(FDBTransaction* tr,
@@ -185,6 +187,8 @@ struct FdbCApi : public ThreadSafeReferenceCounted<FdbCApi> {
 	fdb_error_t (*futureGetCluster)(FDBFuture* f, FDBCluster** outCluster);
 };
 
+// An implementation of ITransaction that wraps a transaction object created on an externally loaded client library.
+// All API calls to that transaction are routed through the external library.
 class DLTransaction : public ITransaction, ThreadSafeReferenceCounted<DLTransaction> {
 public:
 	DLTransaction(Reference<FdbCApi> api, FdbCApi::FDBTransaction* tr) : api(api), tr(tr) {}
@@ -249,6 +253,8 @@ private:
 	FdbCApi::FDBTransaction* const tr;
 };
 
+// An implementation of IDatabase that wraps a database object created on an externally loaded client library.
+// All API calls to that database are routed through the external library.
 class DLDatabase : public IDatabase, ThreadSafeReferenceCounted<DLDatabase> {
 public:
 	DLDatabase(Reference<FdbCApi> api, FdbCApi::FDBDatabase* db) : api(api), db(db), ready(Void()) {}
@@ -265,6 +271,11 @@ public:
 	void setOption(FDBDatabaseOptions::Option option, Optional<StringRef> value = Optional<StringRef>()) override;
 	double getMainThreadBusyness() override;
 
+	// Returns the protocol version reported by a quorum of coordinators
+	// If an expected version is given, the future won't return until the protocol version is different than expected
+	ThreadFuture<ProtocolVersion> getServerProtocol(
+	    Optional<ProtocolVersion> expectedVersion = Optional<ProtocolVersion>()) override;
+
 	void addref() override { ThreadSafeReferenceCounted<DLDatabase>::addref(); }
 	void delref() override { ThreadSafeReferenceCounted<DLDatabase>::delref(); }
 
@@ -279,13 +290,14 @@ private:
 	ThreadFuture<Void> ready;
 };
 
+// An implementation of IClientApi that re-issues API calls to the C API of an externally loaded client library.
+// The DL prefix stands for "dynamic library".
 class DLApi : public IClientApi {
 public:
 	DLApi(std::string fdbCPath, bool unlinkOnLoad = false);
 
 	void selectApiVersion(int apiVersion) override;
 	const char* getClientVersion() override;
-	ThreadFuture<uint64_t> getServerProtocol(const char* clusterFilePath) override;
 
 	void setNetworkOption(FDBNetworkOptions::Option option, Optional<StringRef> value = Optional<StringRef>()) override;
 	void setupNetwork() override;
@@ -312,6 +324,9 @@ private:
 
 class MultiVersionDatabase;
 
+// An implementation of ITransaction that wraps a transaction created either locally or through a dynamically loaded
+// external client. When needed (e.g on cluster version change), the MultiVersionTransaction can automatically replace
+// its wrapped transaction with one from another client.
 class MultiVersionTransaction : public ITransaction, ThreadSafeReferenceCounted<MultiVersionTransaction> {
 public:
 	MultiVersionTransaction(Reference<MultiVersionDatabase> db,
@@ -413,6 +428,9 @@ struct ClientInfo : ClientDesc, ThreadSafeReferenceCounted<ClientInfo> {
 
 class MultiVersionApi;
 
+// An implementation of IDatabase that wraps a database created either locally or through a dynamically loaded
+// external client. The MultiVersionDatabase monitors the protocol version of the cluster and automatically
+// replaces the wrapped database when the protocol version changes.
 class MultiVersionDatabase final : public IDatabase, ThreadSafeReferenceCounted<MultiVersionDatabase> {
 public:
 	MultiVersionDatabase(MultiVersionApi* api,
@@ -426,6 +444,11 @@ public:
 	void setOption(FDBDatabaseOptions::Option option, Optional<StringRef> value = Optional<StringRef>()) override;
 	double getMainThreadBusyness() override;
 
+	// Returns the protocol version reported by a quorum of coordinators
+	// If an expected version is given, the future won't return until the protocol version is different than expected
+	ThreadFuture<ProtocolVersion> getServerProtocol(
+	    Optional<ProtocolVersion> expectedVersion = Optional<ProtocolVersion>()) override;
+
 	void addref() override { ThreadSafeReferenceCounted<MultiVersionDatabase>::addref(); }
 	void delref() override { ThreadSafeReferenceCounted<MultiVersionDatabase>::delref(); }
 
@@ -487,15 +510,19 @@ private:
 		Mutex optionLock;
 	};
 
+	std::string clusterFilePath;
 	const Reference<DatabaseState> dbState;
 	friend class MultiVersionTransaction;
 };
 
+// An implementation of IClientApi that can choose between multiple different client implementations either provided
+// locally within the primary loaded fdb_c client or through any number of dynamically loaded clients.
+//
+// This functionality is used to provide support for multiple protocol versions simultaneously.
 class MultiVersionApi : public IClientApi {
 public:
 	void selectApiVersion(int apiVersion) override;
 	const char* getClientVersion() override;
-	ThreadFuture<uint64_t> getServerProtocol(const char* clusterFilePath) override;
 
 	void setNetworkOption(FDBNetworkOptions::Option option, Optional<StringRef> value = Optional<StringRef>()) override;
 	void setupNetwork() override;

fdbclient/NativeAPI.actor.cpp

@@ -37,6 +37,7 @@
 #include "fdbclient/ClusterInterface.h"
 #include "fdbclient/CoordinationInterface.h"
 #include "fdbclient/DatabaseContext.h"
+#include "fdbclient/GlobalConfig.actor.h"
 #include "fdbclient/JsonBuilder.h"
 #include "fdbclient/KeyRangeMap.h"
 #include "fdbclient/Knobs.h"
@@ -506,12 +507,13 @@ ACTOR static Future<Void> clientStatusUpdateActor(DatabaseContext* cx) {
 				}
 			}
 			cx->clientStatusUpdater.outStatusQ.clear();
-			double clientSamplingProbability = std::isinf(cx->clientInfo->get().clientTxnInfoSampleRate)
-			                                       ? CLIENT_KNOBS->CSI_SAMPLING_PROBABILITY
-			                                       : cx->clientInfo->get().clientTxnInfoSampleRate;
-			int64_t clientTxnInfoSizeLimit = cx->clientInfo->get().clientTxnInfoSizeLimit == -1
-			                                     ? CLIENT_KNOBS->CSI_SIZE_LIMIT
-			                                     : cx->clientInfo->get().clientTxnInfoSizeLimit;
+			wait(GlobalConfig::globalConfig().onInitialized());
+			double sampleRate = GlobalConfig::globalConfig().get<double>(fdbClientInfoTxnSampleRate,
+			                                                             std::numeric_limits<double>::infinity());
+			double clientSamplingProbability =
+			    std::isinf(sampleRate) ? CLIENT_KNOBS->CSI_SAMPLING_PROBABILITY : sampleRate;
+			int64_t sizeLimit = GlobalConfig::globalConfig().get<int64_t>(fdbClientInfoTxnSizeLimit, -1);
+			int64_t clientTxnInfoSizeLimit = sizeLimit == -1 ? CLIENT_KNOBS->CSI_SIZE_LIMIT : sizeLimit;
 			if (!trChunksQ.empty() && deterministicRandom()->random01() < clientSamplingProbability)
 				wait(delExcessClntTxnEntriesActor(&tr, clientTxnInfoSizeLimit));
 
@@ -957,6 +959,8 @@ DatabaseContext::DatabaseContext(Reference<AsyncVar<Reference<ClusterConnectionF
 	getValueSubmitted.init(LiteralStringRef("NativeAPI.GetValueSubmitted"));
 	getValueCompleted.init(LiteralStringRef("NativeAPI.GetValueCompleted"));
 
+	GlobalConfig::create(this, clientInfo);
+
 	monitorProxiesInfoChange = monitorProxiesChange(clientInfo, &proxiesChangeTrigger);
 	clientStatusUpdater.actor = clientStatusUpdateActor(this);
 	cacheListMonitor = monitorCacheList(this);
@@ -1019,9 +1023,13 @@ DatabaseContext::DatabaseContext(Reference<AsyncVar<Reference<ClusterConnectionF
 		        singleKeyRange(LiteralStringRef("consistency_check_suspended"))
 		            .withPrefix(SpecialKeySpace::getModuleRange(SpecialKeySpace::MODULE::MANAGEMENT).begin)));
 		registerSpecialKeySpaceModule(
-		    SpecialKeySpace::MODULE::TRACING,
-		    SpecialKeySpace::IMPLTYPE::READWRITE,
-		    std::make_unique<TracingOptionsImpl>(SpecialKeySpace::getModuleRange(SpecialKeySpace::MODULE::TRACING)));
+		    SpecialKeySpace::MODULE::GLOBALCONFIG, SpecialKeySpace::IMPLTYPE::READWRITE,
+		    std::make_unique<GlobalConfigImpl>(
+		        SpecialKeySpace::getModuleRange(SpecialKeySpace::MODULE::GLOBALCONFIG)));
+		registerSpecialKeySpaceModule(
+		    SpecialKeySpace::MODULE::TRACING, SpecialKeySpace::IMPLTYPE::READWRITE,
+		    std::make_unique<TracingOptionsImpl>(
+		        SpecialKeySpace::getModuleRange(SpecialKeySpace::MODULE::TRACING)));
 		registerSpecialKeySpaceModule(
 		    SpecialKeySpace::MODULE::CONFIGURATION,
 		    SpecialKeySpace::IMPLTYPE::READWRITE,
@@ -1271,14 +1279,16 @@ Future<Void> DatabaseContext::onProxiesChanged() {
 }
 
 bool DatabaseContext::sampleReadTags() const {
-	return clientInfo->get().transactionTagSampleRate > 0 &&
-	       deterministicRandom()->random01() <= clientInfo->get().transactionTagSampleRate;
+	double sampleRate = GlobalConfig::globalConfig().get(transactionTagSampleRate, CLIENT_KNOBS->READ_TAG_SAMPLE_RATE);
+	return sampleRate > 0 && deterministicRandom()->random01() <= sampleRate;
 }
 
 bool DatabaseContext::sampleOnCost(uint64_t cost) const {
-	if (clientInfo->get().transactionTagSampleCost <= 0)
+	double sampleCost =
+	    GlobalConfig::globalConfig().get<double>(transactionTagSampleCost, CLIENT_KNOBS->COMMIT_SAMPLE_COST);
+	if (sampleCost <= 0)
 		return false;
-	return deterministicRandom()->random01() <= (double)cost / clientInfo->get().transactionTagSampleCost;
+	return deterministicRandom()->random01() <= (double)cost / sampleCost;
 }
 
 int64_t extractIntOption(Optional<StringRef> value, int64_t minValue, int64_t maxValue) {
@@ -2483,7 +2493,6 @@ ACTOR Future<Version> watchValue(Future<Version> version,
 				cx->invalidateCache(key);
 				wait(delay(CLIENT_KNOBS->WRONG_SHARD_SERVER_DELAY, info.taskID));
 			} else if (e.code() == error_code_watch_cancelled || e.code() == error_code_process_behind) {
-				TEST(e.code() == error_code_watch_cancelled); // Too many watches on the storage server, poll for changes instead
 				TEST(e.code() == error_code_watch_cancelled); // Too many watches on storage server, poll for changes
 				TEST(e.code() == error_code_process_behind); // The storage servers are all behind
 				wait(delay(CLIENT_KNOBS->WATCH_POLLING_TIME, info.taskID));
@@ -4908,9 +4917,18 @@ ACTOR Future<ProtocolVersion> coordinatorProtocolsFetcher(Reference<ClusterConne
 	return ProtocolVersion(majorityProtocol);
 }
 
-ACTOR Future<uint64_t> getCoordinatorProtocols(Reference<ClusterConnectionFile> f) {
-	ProtocolVersion protocolVersion = wait(coordinatorProtocolsFetcher(f));
-	return protocolVersion.version();
+// Returns the protocol version reported by a quorum of coordinators
+// If an expected version is given, the future won't return until the protocol version is different than expected
+ACTOR Future<ProtocolVersion> getClusterProtocol(Reference<ClusterConnectionFile> f,
+                                                 Optional<ProtocolVersion> expectedVersion) {
+	loop {
+		ProtocolVersion protocolVersion = wait(coordinatorProtocolsFetcher(f));
+		if (!expectedVersion.present() || protocolVersion != expectedVersion.get()) {
+			return protocolVersion;
+		} else {
+			wait(delay(2.0)); // TODO: this is temporary, so not making into a knob yet
+		}
+	}
 }
 
 uint32_t Transaction::getSize() {
@@ -5378,9 +5396,8 @@ void Transaction::checkDeferredError() {
 
 Reference<TransactionLogInfo> Transaction::createTrLogInfoProbabilistically(const Database& cx) {
 	if (!cx->isError()) {
-		double clientSamplingProbability = std::isinf(cx->clientInfo->get().clientTxnInfoSampleRate)
-		                                       ? CLIENT_KNOBS->CSI_SAMPLING_PROBABILITY
-		                                       : cx->clientInfo->get().clientTxnInfoSampleRate;
+		double clientSamplingProbability = GlobalConfig::globalConfig().get<double>(
+		    fdbClientInfoTxnSampleRate, CLIENT_KNOBS->CSI_SAMPLING_PROBABILITY);
 		if (((networkOptions.logClientInfo.present() && networkOptions.logClientInfo.get()) || BUGGIFY) &&
 		    deterministicRandom()->random01() < clientSamplingProbability &&
 		    (!g_network->isSimulated() || !g_simulator.speedUpSimulation)) {

fdbclient/NativeAPI.actor.h

@@ -400,7 +400,10 @@ ACTOR Future<Void> snapCreate(Database cx, Standalone<StringRef> snapCmd, UID sn
 // Checks with Data Distributor that it is safe to mark all servers in exclusions as failed
 ACTOR Future<bool> checkSafeExclusions(Database cx, vector<AddressExclusion> exclusions);
 
-ACTOR Future<uint64_t> getCoordinatorProtocols(Reference<ClusterConnectionFile> f);
+// Returns the protocol version reported by a quorum of coordinators
+// If an expected version is given, the future won't return until the protocol version is different than expected
+ACTOR Future<ProtocolVersion> getClusterProtocol(Reference<ClusterConnectionFile> f,
+                                                 Optional<ProtocolVersion> expectedVersion);
 
 inline uint64_t getWriteOperationCost(uint64_t bytes) {
 	return bytes / std::max(1, CLIENT_KNOBS->WRITE_COST_BYTE_FACTOR) + 1;

fdbclient/SpecialKeySpace.actor.cpp

@@ -23,6 +23,7 @@
 
 #include "fdbclient/Knobs.h"
 #include "fdbclient/ProcessInterface.h"
+#include "fdbclient/GlobalConfig.actor.h"
 #include "fdbclient/SpecialKeySpace.actor.h"
 #include "flow/Arena.h"
 #include "flow/UnitTest.h"
@@ -65,6 +66,8 @@ std::unordered_map<SpecialKeySpace::MODULE, KeyRange> SpecialKeySpace::moduleToB
 	{ SpecialKeySpace::MODULE::ERRORMSG, singleKeyRange(LiteralStringRef("\xff\xff/error_message")) },
 	{ SpecialKeySpace::MODULE::CONFIGURATION,
 	  KeyRangeRef(LiteralStringRef("\xff\xff/configuration/"), LiteralStringRef("\xff\xff/configuration0")) },
+	{ SpecialKeySpace::MODULE::GLOBALCONFIG,
+	  KeyRangeRef(LiteralStringRef("\xff\xff/global_config/"), LiteralStringRef("\xff\xff/global_config0")) },
 	{ SpecialKeySpace::MODULE::TRACING,
 	  KeyRangeRef(LiteralStringRef("\xff\xff/tracing/"), LiteralStringRef("\xff\xff/tracing0")) },
 	{ SpecialKeySpace::MODULE::ACTORLINEAGE,
@@ -1372,10 +1375,129 @@ Future<Optional<std::string>> ConsistencyCheckImpl::commit(ReadYourWritesTransac
 	return Optional<std::string>();
 }
 
-TracingOptionsImpl::TracingOptionsImpl(KeyRangeRef kr) : SpecialKeyRangeRWImpl(kr) {
-	TraceEvent("TracingOptionsImpl::TracingOptionsImpl").detail("Range", kr);
+GlobalConfigImpl::GlobalConfigImpl(KeyRangeRef kr) : SpecialKeyRangeRWImpl(kr) {}
+
+// Returns key-value pairs for each value stored in the global configuration
+// framework within the range specified. The special-key-space getrange
+// function should only be used for informational purposes. All values are
+// returned as strings regardless of their true type.
+Future<Standalone<RangeResultRef>> GlobalConfigImpl::getRange(ReadYourWritesTransaction* ryw, KeyRangeRef kr) const {
+	Standalone<RangeResultRef> result;
+
+	auto& globalConfig = GlobalConfig::globalConfig();
+	KeyRangeRef modified =
+	    KeyRangeRef(kr.begin.removePrefix(getKeyRange().begin), kr.end.removePrefix(getKeyRange().begin));
+	std::map<KeyRef, Reference<ConfigValue>> values = globalConfig.get(modified);
+	for (const auto& [key, config] : values) {
+		Key prefixedKey = key.withPrefix(getKeyRange().begin);
+		if (config.isValid() && config->value.has_value()) {
+			if (config->value.type() == typeid(StringRef)) {
+				result.push_back_deep(result.arena(),
+				                      KeyValueRef(prefixedKey, std::any_cast<StringRef>(config->value).toString()));
+			} else if (config->value.type() == typeid(int64_t)) {
+				result.push_back_deep(result.arena(),
+				                      KeyValueRef(prefixedKey, std::to_string(std::any_cast<int64_t>(config->value))));
+			} else if (config->value.type() == typeid(float)) {
+				result.push_back_deep(result.arena(),
+				                      KeyValueRef(prefixedKey, std::to_string(std::any_cast<float>(config->value))));
+			} else if (config->value.type() == typeid(double)) {
+				result.push_back_deep(result.arena(),
+				                      KeyValueRef(prefixedKey, std::to_string(std::any_cast<double>(config->value))));
+			} else {
+				ASSERT(false);
+			}
+		}
+	}
+
+	return result;
 }
 
+// Marks the key for insertion into global configuration.
+void GlobalConfigImpl::set(ReadYourWritesTransaction* ryw, const KeyRef& key, const ValueRef& value) {
+	ryw->getSpecialKeySpaceWriteMap().insert(key, std::make_pair(true, Optional<Value>(value)));
+}
+
+// Writes global configuration changes to durable memory. Also writes the
+// changes made in the transaction to a recent history set, and updates the
+// latest version which the global configuration was updated at.
+ACTOR Future<Optional<std::string>> globalConfigCommitActor(GlobalConfigImpl* globalConfig,
+                                                            ReadYourWritesTransaction* ryw) {
+	state Transaction& tr = ryw->getTransaction();
+
+	// History should only contain three most recent updates. If it currently
+	// has three items, remove the oldest to make room for a new item.
+	Standalone<RangeResultRef> history = wait(tr.getRange(globalConfigHistoryKeys, CLIENT_KNOBS->TOO_MANY));
+	constexpr int kGlobalConfigMaxHistorySize = 3;
+	if (history.size() > kGlobalConfigMaxHistorySize - 1) {
+		for (int i = 0; i < history.size() - (kGlobalConfigMaxHistorySize - 1); ++i) {
+			tr.clear(history[i].key);
+		}
+	}
+
+	VersionHistory vh{ 0 };
+
+	// Transform writes from the special-key-space (\xff\xff/global_config/) to
+	// the system key space (\xff/globalConfig/), and writes mutations to
+	// latest version history.
+	state RangeMap<Key, std::pair<bool, Optional<Value>>, KeyRangeRef>::Ranges ranges =
+	    ryw->getSpecialKeySpaceWriteMap().containedRanges(specialKeys);
+	state RangeMap<Key, std::pair<bool, Optional<Value>>, KeyRangeRef>::iterator iter = ranges.begin();
+	while (iter != ranges.end()) {
+		std::pair<bool, Optional<Value>> entry = iter->value();
+		if (entry.first) {
+			if (entry.second.present() && iter->begin().startsWith(globalConfig->getKeyRange().begin)) {
+				Key bareKey = iter->begin().removePrefix(globalConfig->getKeyRange().begin);
+				vh.mutations.emplace_back_deep(vh.mutations.arena(),
+				                               MutationRef(MutationRef::SetValue, bareKey, entry.second.get()));
+
+				Key systemKey = bareKey.withPrefix(globalConfigKeysPrefix);
+				tr.set(systemKey, entry.second.get());
+			} else if (!entry.second.present() && iter->range().begin.startsWith(globalConfig->getKeyRange().begin) &&
+			           iter->range().end.startsWith(globalConfig->getKeyRange().begin)) {
+				KeyRef bareRangeBegin = iter->range().begin.removePrefix(globalConfig->getKeyRange().begin);
+				KeyRef bareRangeEnd = iter->range().end.removePrefix(globalConfig->getKeyRange().begin);
+				vh.mutations.emplace_back_deep(vh.mutations.arena(),
+				                               MutationRef(MutationRef::ClearRange, bareRangeBegin, bareRangeEnd));
+
+				Key systemRangeBegin = bareRangeBegin.withPrefix(globalConfigKeysPrefix);
+				Key systemRangeEnd = bareRangeEnd.withPrefix(globalConfigKeysPrefix);
+				tr.clear(KeyRangeRef(systemRangeBegin, systemRangeEnd));
+			}
+		}
+		++iter;
+	}
+
+	// Record the mutations in this commit into the global configuration history.
+	Key historyKey = addVersionStampAtEnd(globalConfigHistoryPrefix);
+	ObjectWriter historyWriter(IncludeVersion());
+	historyWriter.serialize(vh);
+	tr.atomicOp(historyKey, historyWriter.toStringRef(), MutationRef::SetVersionstampedKey);
+
+	// Write version key to trigger update in cluster controller.
+	tr.atomicOp(globalConfigVersionKey,
+	            LiteralStringRef("0123456789\x00\x00\x00\x00"), // versionstamp
+	            MutationRef::SetVersionstampedValue);
+
+	return Optional<std::string>();
+}
+
+// Called when a transaction includes keys in the global configuration special-key-space range.
+Future<Optional<std::string>> GlobalConfigImpl::commit(ReadYourWritesTransaction* ryw) {
+	return globalConfigCommitActor(this, ryw);
+}
+
+// Marks the range for deletion from global configuration.
+void GlobalConfigImpl::clear(ReadYourWritesTransaction* ryw, const KeyRangeRef& range) {
+	ryw->getSpecialKeySpaceWriteMap().insert(range, std::make_pair(true, Optional<Value>()));
+}
+
+// Marks the key for deletion from global configuration.
+void GlobalConfigImpl::clear(ReadYourWritesTransaction* ryw, const KeyRef& key) {
+	ryw->getSpecialKeySpaceWriteMap().insert(key, std::make_pair(true, Optional<Value>()));
+}
+
+TracingOptionsImpl::TracingOptionsImpl(KeyRangeRef kr) : SpecialKeyRangeRWImpl(kr) {}
+
 Future<Standalone<RangeResultRef>> TracingOptionsImpl::getRange(ReadYourWritesTransaction* ryw, KeyRangeRef kr) const {
 	Standalone<RangeResultRef> result;
 	for (const auto& option : SpecialKeySpace::getTracingOptions()) {

fdbclient/SpecialKeySpace.actor.h

@@ -147,6 +147,7 @@ public:
 		CONFIGURATION, // Configuration of the cluster
 		CONNECTIONSTRING,
 		ERRORMSG, // A single key space contains a json string which describes the last error in special-key-space
+		GLOBALCONFIG, // Global configuration options synchronized to all nodes
 		MANAGEMENT, // Management-API
 		METRICS, // data-distribution metrics
 		TESTONLY, // only used by correctness tests
@@ -337,6 +338,16 @@ public:
 	Future<Optional<std::string>> commit(ReadYourWritesTransaction* ryw) override;
 };
 
+class GlobalConfigImpl : public SpecialKeyRangeRWImpl {
+public:
+	explicit GlobalConfigImpl(KeyRangeRef kr);
+	Future<Standalone<RangeResultRef>> getRange(ReadYourWritesTransaction* ryw, KeyRangeRef kr) const override;
+	void set(ReadYourWritesTransaction* ryw, const KeyRef& key, const ValueRef& value) override;
+	Future<Optional<std::string>> commit(ReadYourWritesTransaction* ryw) override;
+	void clear(ReadYourWritesTransaction* ryw, const KeyRangeRef& range) override;
+	void clear(ReadYourWritesTransaction* ryw, const KeyRef& key) override;
+};
+
 class TracingOptionsImpl : public SpecialKeyRangeRWImpl {
 public:
 	explicit TracingOptionsImpl(KeyRangeRef kr);

fdbclient/SystemData.cpp

@@ -632,7 +632,18 @@ std::string encodeFailedServersKey(AddressExclusion const& addr) {
 	return failedServersPrefix.toString() + addr.toString();
 }
 
-const KeyRangeRef workerListKeys(LiteralStringRef("\xff/worker/"), LiteralStringRef("\xff/worker0"));
+// const KeyRangeRef globalConfigKeys( LiteralStringRef("\xff/globalConfig/"), LiteralStringRef("\xff/globalConfig0") );
+// const KeyRef globalConfigPrefix = globalConfigKeys.begin;
+
+const KeyRangeRef globalConfigDataKeys( LiteralStringRef("\xff/globalConfig/k/"), LiteralStringRef("\xff/globalConfig/k0") );
+const KeyRef globalConfigKeysPrefix = globalConfigDataKeys.begin;
+
+const KeyRangeRef globalConfigHistoryKeys( LiteralStringRef("\xff/globalConfig/h/"), LiteralStringRef("\xff/globalConfig/h0") );
+const KeyRef globalConfigHistoryPrefix = globalConfigHistoryKeys.begin;
+
+const KeyRef globalConfigVersionKey = LiteralStringRef("\xff/globalConfig/v");
+
+const KeyRangeRef workerListKeys( LiteralStringRef("\xff/worker/"), LiteralStringRef("\xff/worker0") );
 const KeyRef workerListPrefix = workerListKeys.begin;
 
 const Key workerListKeyFor(StringRef processID) {
@@ -748,8 +759,7 @@ const KeyRef tagThrottleCountKey = LiteralStringRef("\xff\x02/throttledTags/manu
 // Client status info prefix
 const KeyRangeRef fdbClientInfoPrefixRange(LiteralStringRef("\xff\x02/fdbClientInfo/"),
                                            LiteralStringRef("\xff\x02/fdbClientInfo0"));
-const KeyRef fdbClientInfoTxnSampleRate = LiteralStringRef("\xff\x02/fdbClientInfo/client_txn_sample_rate/");
-const KeyRef fdbClientInfoTxnSizeLimit = LiteralStringRef("\xff\x02/fdbClientInfo/client_txn_size_limit/");
+// See remaining fields in GlobalConfig.actor.h
 
 // ConsistencyCheck settings
 const KeyRef fdbShouldConsistencyCheckBeSuspended = LiteralStringRef("\xff\x02/ConsistencyCheck/Suspend");

fdbclient/SystemData.h

@@ -230,6 +230,30 @@ extern const KeyRef failedServersVersionKey; // The value of this key shall be c
 const AddressExclusion decodeFailedServersKey(KeyRef const& key); // where key.startsWith(failedServersPrefix)
 std::string encodeFailedServersKey(AddressExclusion const&);
 
+//   "\xff/globalConfig/[[option]]" := "value"
+//	 An umbrella prefix for global configuration data synchronized to all nodes.
+// extern const KeyRangeRef globalConfigData;
+// extern const KeyRef globalConfigDataPrefix;
+
+//   "\xff/globalConfig/k/[[key]]" := "value"
+//	 Key-value pairs that have been set. The range this keyspace represents
+//	 contains all globally configured options.
+extern const KeyRangeRef globalConfigDataKeys;
+extern const KeyRef globalConfigKeysPrefix;
+
+//   "\xff/globalConfig/h/[[version]]" := "value"
+//   Maps a commit version to a list of mutations made to the global
+//   configuration at that commit. Shipped to nodes periodically. In general,
+//   clients should not write to keys in this keyspace; it will be written
+//   automatically when updating global configuration keys.
+extern const KeyRangeRef globalConfigHistoryKeys;
+extern const KeyRef globalConfigHistoryPrefix;
+
+//   "\xff/globalConfig/v" := "version"
+//   Read-only key which returns the commit version of the most recent mutation
+//   made to the global configuration keyspace.
+extern const KeyRef globalConfigVersionKey;
+
 //	"\xff/workers/[[processID]]" := ""
 //	Asynchronously updated by the cluster controller, this is a list of fdbserver processes that have joined the cluster
 //	and are currently (recently) available
@@ -355,8 +379,6 @@ extern const KeyRangeRef applyMutationsKeyVersionCountRange;
 
 // FdbClient Info prefix
 extern const KeyRangeRef fdbClientInfoPrefixRange;
-extern const KeyRef fdbClientInfoTxnSampleRate;
-extern const KeyRef fdbClientInfoTxnSizeLimit;
 
 // Consistency Check settings
 extern const KeyRef fdbShouldConsistencyCheckBeSuspended;

fdbclient/ThreadSafeTransaction.cpp

@@ -97,6 +97,15 @@ double ThreadSafeDatabase::getMainThreadBusyness() {
 	return g_network->networkInfo.metrics.networkBusyness;
 }
 
+// Returns the protocol version reported by a quorum of coordinators
+// If an expected version is given, the future won't return until the protocol version is different than expected
+ThreadFuture<ProtocolVersion> ThreadSafeDatabase::getServerProtocol(Optional<ProtocolVersion> expectedVersion) {
+	DatabaseContext* db = this->db;
+	return onMainThread([db, expectedVersion]() -> Future<ProtocolVersion> {
+		return getClusterProtocol(db->getConnectionFile(), expectedVersion);
+	});
+}
+
 ThreadSafeDatabase::ThreadSafeDatabase(std::string connFilename, int apiVersion) {
 	ClusterConnectionFile* connFile =
 	    new ClusterConnectionFile(ClusterConnectionFile::lookupClusterFileName(connFilename).first);
@@ -407,16 +416,6 @@ const char* ThreadSafeApi::getClientVersion() {
 	return clientVersion.c_str();
 }
 
-// Wait until a quorum of coordinators with the same protocol version are available, and then return that protocol
-// version.
-ThreadFuture<uint64_t> ThreadSafeApi::getServerProtocol(const char* clusterFilePath) {
-	return onMainThread([clusterFilePath = std::string(clusterFilePath)]() -> Future<uint64_t> {
-		auto [clusterFile, isDefault] = ClusterConnectionFile::lookupClusterFileName(clusterFilePath);
-		Reference<ClusterConnectionFile> f = Reference<ClusterConnectionFile>(new ClusterConnectionFile(clusterFile));
-		return getCoordinatorProtocols(f);
-	});
-}
-
 void ThreadSafeApi::setNetworkOption(FDBNetworkOptions::Option option, Optional<StringRef> value) {
 	if (option == FDBNetworkOptions::EXTERNAL_CLIENT_TRANSPORT_ID) {
 		if (value.present()) {

fdbclient/ThreadSafeTransaction.h

@@ -27,6 +27,8 @@
 #include "fdbclient/ClusterInterface.h"
 #include "fdbclient/IClientApi.h"
 
+// An implementation of IDatabase that serializes operations onto the network thread and interacts with the lower-level
+// client APIs exposed by NativeAPI and ReadYourWrites.
 class ThreadSafeDatabase : public IDatabase, public ThreadSafeReferenceCounted<ThreadSafeDatabase> {
 public:
 	~ThreadSafeDatabase() override;
@@ -37,9 +39,14 @@ public:
 	void setOption(FDBDatabaseOptions::Option option, Optional<StringRef> value = Optional<StringRef>()) override;
 	double getMainThreadBusyness() override;
 
-	ThreadFuture<Void>
-	onConnected(); // Returns after a majority of coordination servers are available and have reported a leader. The
-	               // cluster file therefore is valid, but the database might be unavailable.
+	// Returns the protocol version reported by a quorum of coordinators
+	// If an expected version is given, the future won't return until the protocol version is different than expected
+	ThreadFuture<ProtocolVersion> getServerProtocol(
+	    Optional<ProtocolVersion> expectedVersion = Optional<ProtocolVersion>()) override;
+
+	// Returns after a majority of coordination servers are available and have reported a leader. The
+	// cluster file therefore is valid, but the database might be unavailable.
+	ThreadFuture<Void> onConnected();
 
 	void addref() override { ThreadSafeReferenceCounted<ThreadSafeDatabase>::addref(); }
 	void delref() override { ThreadSafeReferenceCounted<ThreadSafeDatabase>::delref(); }
@@ -58,6 +65,8 @@ public: // Internal use only
 	DatabaseContext* unsafeGetPtr() const { return db; }
 };
 
+// An implementation of ITransaction that serializes operations onto the network thread and interacts with the
+// lower-level client APIs exposed by NativeAPI and ReadYourWrites.
 class ThreadSafeTransaction : public ITransaction, ThreadSafeReferenceCounted<ThreadSafeTransaction>, NonCopyable {
 public:
 	explicit ThreadSafeTransaction(DatabaseContext* cx);
@@ -135,11 +144,12 @@ private:
 	ReadYourWritesTransaction* tr;
 };
 
+// An implementation of IClientApi that serializes operations onto the network thread and interacts with the lower-level
+// client APIs exposed by NativeAPI and ReadYourWrites.
 class ThreadSafeApi : public IClientApi, ThreadSafeReferenceCounted<ThreadSafeApi> {
 public:
 	void selectApiVersion(int apiVersion) override;
 	const char* getClientVersion() override;
-	ThreadFuture<uint64_t> getServerProtocol(const char* clusterFilePath) override;
 
 	void setNetworkOption(FDBNetworkOptions::Option option, Optional<StringRef> value = Optional<StringRef>()) override;
 	void setupNetwork() override;

fdbclient/Tuple.cpp

@@ -20,7 +20,20 @@
 
 #include "fdbclient/Tuple.h"
 
-static size_t find_string_terminator(const StringRef data, size_t offset) {
+// TODO: Many functions copied from bindings/flow/Tuple.cpp. Merge at some point.
+static float bigEndianFloat(float orig) {
+	int32_t big = *(int32_t*)&orig;
+	big = bigEndian32(big);
+	return *(float*)&big;
+}
+
+static double bigEndianDouble(double orig) {
+	int64_t big = *(int64_t*)&orig;
+	big = bigEndian64(big);
+	return *(double*)&big;
+}
+
+static size_t findStringTerminator(const StringRef data, size_t offset) {
 	size_t i = offset;
 	while (i < data.size() - 1 && !(data[i] == '\x00' && data[i + 1] != (uint8_t)'\xff')) {
 		i += (data[i] == '\x00' ? 2 : 1);
@@ -29,6 +42,20 @@ static size_t find_string_terminator(const StringRef data, size_t offset) {
 	return i;
 }
 
+// If encoding and the sign bit is 1 (the number is negative), flip all the bits.
+// If decoding and the sign bit is 0 (the number is negative), flip all the bits.
+// Otherwise, the number is positive, so flip the sign bit.
+static void adjustFloatingPoint(uint8_t* bytes, size_t size, bool encode) {
+	if ((encode && ((uint8_t)(bytes[0] & 0x80) != (uint8_t)0x00)) ||
+	    (!encode && ((uint8_t)(bytes[0] & 0x80) != (uint8_t)0x80))) {
+		for (size_t i = 0; i < size; i++) {
+			bytes[i] ^= (uint8_t)0xff;
+		}
+	} else {
+		bytes[0] ^= (uint8_t)0x80;
+	}
+}
+
 Tuple::Tuple(StringRef const& str, bool exclude_incomplete) {
 	data.append(data.arena(), str.begin(), str.size());
 
@@ -37,9 +64,13 @@ Tuple::Tuple(StringRef const& str, bool exclude_incomplete) {
 		offsets.push_back(i);
 
 		if (data[i] == '\x01' || data[i] == '\x02') {
-			i = find_string_terminator(str, i + 1) + 1;
+			i = findStringTerminator(str, i + 1) + 1;
 		} else if (data[i] >= '\x0c' && data[i] <= '\x1c') {
 			i += abs(data[i] - '\x14') + 1;
+		} else if (data[i] == 0x20) {
+			i += sizeof(float) + 1;
+		} else if (data[i] == 0x21) {
+			i += sizeof(double) + 1;
 		} else if (data[i] == '\x00') {
 			i += 1;
 		} else {
@@ -113,6 +144,29 @@ Tuple& Tuple::append(int64_t value) {
 	return *this;
 }
 
+Tuple& Tuple::appendFloat(float value) {
+	offsets.push_back(data.size());
+	float swap = bigEndianFloat(value);
+	uint8_t* bytes = (uint8_t*)&swap;
+	adjustFloatingPoint(bytes, sizeof(float), true);
+
+	data.push_back(data.arena(), 0x20);
+	data.append(data.arena(), bytes, sizeof(float));
+	return *this;
+}
+
+Tuple& Tuple::appendDouble(double value) {
+	offsets.push_back(data.size());
+	double swap = value;
+	swap = bigEndianDouble(swap);
+	uint8_t* bytes = (uint8_t*)&swap;
+	adjustFloatingPoint(bytes, sizeof(double), true);
+
+	data.push_back(data.arena(), 0x21);
+	data.append(data.arena(), bytes, sizeof(double));
+	return *this;
+}
+
 Tuple& Tuple::appendNull() {
 	offsets.push_back(data.size());
 	data.push_back(data.arena(), (uint8_t)'\x00');
@@ -134,6 +188,10 @@ Tuple::ElementType Tuple::getType(size_t index) const {
 		return ElementType::UTF8;
 	} else if (code >= '\x0c' && code <= '\x1c') {
 		return ElementType::INT;
+	} else if (code == 0x20) {
+		return ElementType::FLOAT;
+	} else if (code == 0x21) {
+		return ElementType::DOUBLE;
 	} else {
 		throw invalid_tuple_data_type();
 	}
@@ -228,6 +286,45 @@ int64_t Tuple::getInt(size_t index, bool allow_incomplete) const {
 	return swap;
 }
 
+// TODO: Combine with bindings/flow/Tuple.*. This code is copied from there.
+float Tuple::getFloat(size_t index) const {
+	if (index >= offsets.size()) {
+		throw invalid_tuple_index();
+	}
+	ASSERT_LT(offsets[index], data.size());
+	uint8_t code = data[offsets[index]];
+	if (code != 0x20) {
+		throw invalid_tuple_data_type();
+	}
+
+	float swap;
+	uint8_t* bytes = (uint8_t*)&swap;
+	ASSERT_LE(offsets[index] + 1 + sizeof(float), data.size());
+	swap = *(float*)(data.begin() + offsets[index] + 1);
+	adjustFloatingPoint(bytes, sizeof(float), false);
+
+	return bigEndianFloat(swap);
+}
+
+double Tuple::getDouble(size_t index) const {
+	if (index >= offsets.size()) {
+		throw invalid_tuple_index();
+	}
+	ASSERT_LT(offsets[index], data.size());
+	uint8_t code = data[offsets[index]];
+	if (code != 0x21) {
+		throw invalid_tuple_data_type();
+	}
+
+	double swap;
+	uint8_t* bytes = (uint8_t*)&swap;
+	ASSERT_LE(offsets[index] + 1 + sizeof(double), data.size());
+	swap = *(double*)(data.begin() + offsets[index] + 1);
+	adjustFloatingPoint(bytes, sizeof(double), false);
+
+	return bigEndianDouble(swap);
+}
+
 KeyRange Tuple::range(Tuple const& tuple) const {
 	VectorRef<uint8_t> begin;
 	VectorRef<uint8_t> end;

fdbclient/Tuple.h

@@ -38,6 +38,10 @@ struct Tuple {
 	Tuple& append(Tuple const& tuple);
 	Tuple& append(StringRef const& str, bool utf8 = false);
 	Tuple& append(int64_t);
+	// There are some ambiguous append calls in fdbclient, so to make it easier
+	// to add append for floats and doubles, name them differently for now.
+	Tuple& appendFloat(float);
+	Tuple& appendDouble(double);
 	Tuple& appendNull();
 
 	StringRef pack() const { return StringRef(data.begin(), data.size()); }
@@ -47,7 +51,7 @@ struct Tuple {
 		return append(t);
 	}
 
-	enum ElementType { NULL_TYPE, INT, BYTES, UTF8 };
+	enum ElementType { NULL_TYPE, INT, BYTES, UTF8, FLOAT, DOUBLE };
 
 	// this is number of elements, not length of data
 	size_t size() const { return offsets.size(); }
@@ -55,6 +59,8 @@ struct Tuple {
 	ElementType getType(size_t index) const;
 	Standalone<StringRef> getString(size_t index) const;
 	int64_t getInt(size_t index, bool allow_incomplete = false) const;
+	float getFloat(size_t index) const;
+	double getDouble(size_t index) const;
 
 	KeyRange range(Tuple const& tuple = Tuple()) const;
 

fdbrpc/AsyncFileNonDurable.actor.h

@@ -197,7 +197,7 @@ private:
 		this->file = file;
 		this->filename = filename;
 		this->diskParameters = diskParameters;
-		maxWriteDelay = 5.0;
+		maxWriteDelay = FLOW_KNOBS->NON_DURABLE_MAX_WRITE_DELAY;
 		hasBeenSynced = false;
 
 		killMode = (KillMode)deterministicRandom()->randomInt(1, 3);
@@ -434,7 +434,8 @@ private:
 		state TaskPriority currentTaskID = g_network->getCurrentTask();
 		wait(g_simulator.onMachine(currentProcess));
 
-		state double delayDuration = deterministicRandom()->random01() * self->maxWriteDelay;
+		state double delayDuration =
+		    g_simulator.speedUpSimulation ? 0.0001 : (deterministicRandom()->random01() * self->maxWriteDelay);
 		state Standalone<StringRef> dataCopy(StringRef((uint8_t*)data, length));
 
 		state Future<bool> startSyncFuture = self->startSyncPromise.getFuture();
@@ -606,7 +607,8 @@ private:
 		state TaskPriority currentTaskID = g_network->getCurrentTask();
 		wait(g_simulator.onMachine(currentProcess));
 
-		state double delayDuration = deterministicRandom()->random01() * self->maxWriteDelay;
+		state double delayDuration =
+		    g_simulator.speedUpSimulation ? 0.0001 : (deterministicRandom()->random01() * self->maxWriteDelay);
 		state Future<bool> startSyncFuture = self->startSyncPromise.getFuture();
 
 		try {

fdbrpc/Locality.cpp

@@ -63,7 +63,7 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 		default:
 			return ProcessClass::NeverAssign;
 		}
-	case ProcessClass::CommitProxy:
+	case ProcessClass::CommitProxy: // Resolver, Master, CommitProxy, and GrvProxy need to be the same besides best fit
 		switch (_class) {
 		case ProcessClass::CommitProxyClass:
 			return ProcessClass::BestFit;
@@ -71,10 +71,6 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 			return ProcessClass::GoodFit;
 		case ProcessClass::UnsetClass:
 			return ProcessClass::UnsetFit;
-		case ProcessClass::GrvProxyClass:
-			return ProcessClass::OkayFit;
-		case ProcessClass::ResolutionClass:
-			return ProcessClass::OkayFit;
 		case ProcessClass::TransactionClass:
 			return ProcessClass::OkayFit;
 		case ProcessClass::CoordinatorClass:
@@ -84,7 +80,7 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 		default:
 			return ProcessClass::WorstFit;
 		}
-	case ProcessClass::GrvProxy:
+	case ProcessClass::GrvProxy: // Resolver, Master, CommitProxy, and GrvProxy need to be the same besides best fit
 		switch (_class) {
 		case ProcessClass::GrvProxyClass:
 			return ProcessClass::BestFit;
@@ -92,10 +88,6 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 			return ProcessClass::GoodFit;
 		case ProcessClass::UnsetClass:
 			return ProcessClass::UnsetFit;
-		case ProcessClass::CommitProxyClass:
-			return ProcessClass::OkayFit;
-		case ProcessClass::ResolutionClass:
-			return ProcessClass::OkayFit;
 		case ProcessClass::TransactionClass:
 			return ProcessClass::OkayFit;
 		case ProcessClass::CoordinatorClass:
@@ -105,7 +97,7 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 		default:
 			return ProcessClass::WorstFit;
 		}
-	case ProcessClass::Master:
+	case ProcessClass::Master: // Resolver, Master, CommitProxy, and GrvProxy need to be the same besides best fit
 		switch (_class) {
 		case ProcessClass::MasterClass:
 			return ProcessClass::BestFit;
@@ -113,7 +105,7 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 			return ProcessClass::GoodFit;
 		case ProcessClass::UnsetClass:
 			return ProcessClass::UnsetFit;
-		case ProcessClass::ResolutionClass:
+		case ProcessClass::TransactionClass:
 			return ProcessClass::OkayFit;
 		case ProcessClass::CoordinatorClass:
 		case ProcessClass::TesterClass:
@@ -122,7 +114,7 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 		default:
 			return ProcessClass::WorstFit;
 		}
-	case ProcessClass::Resolver:
+	case ProcessClass::Resolver: // Resolver, Master, CommitProxy, and GrvProxy need to be the same besides best fit
 		switch (_class) {
 		case ProcessClass::ResolutionClass:
 			return ProcessClass::BestFit;
@@ -147,8 +139,6 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 			return ProcessClass::GoodFit;
 		case ProcessClass::UnsetClass:
 			return ProcessClass::UnsetFit;
-		case ProcessClass::ResolutionClass:
-			return ProcessClass::OkayFit;
 		case ProcessClass::TransactionClass:
 			return ProcessClass::OkayFit;
 		case ProcessClass::CoordinatorClass:
@@ -167,8 +157,6 @@ ProcessClass::Fitness ProcessClass::machineClassFitness(ClusterRole role) const
 			return ProcessClass::GoodFit;
 		case ProcessClass::UnsetClass:
 			return ProcessClass::UnsetFit;
-		case ProcessClass::ResolutionClass:
-			return ProcessClass::OkayFit;
 		case ProcessClass::TransactionClass:
 			return ProcessClass::OkayFit;
 		case ProcessClass::CoordinatorClass:

fdbserver/SimulatedCluster.actor.cpp

@@ -21,6 +21,7 @@
 #include <cstdint>
 #include <fstream>
 #include <ostream>
+#include <sstream>
 #include "fdbrpc/Locality.h"
 #include "fdbrpc/simulator.h"
 #include "fdbclient/DatabaseContext.h"
@@ -874,7 +875,9 @@ void SimulationConfig::set_config(std::string config) {
 StringRef StringRefOf(const char* s) {
 	return StringRef((uint8_t*)s, strlen(s));
 }
-
+// Generates and sets an appropriate configuration for the database according to
+// the provided testConfig. Some attributes are randomly generated for more coverage
+// of different combinations
 void SimulationConfig::generateNormalConfig(const TestConfig& testConfig) {
 	set_config("new");
 	const bool simple = false; // Set true to simplify simulation configs for easier debugging
@@ -897,7 +900,9 @@ void SimulationConfig::generateNormalConfig(const TestConfig& testConfig) {
 		db.resolverCount = deterministicRandom()->randomInt(1, 7);
 	int storage_engine_type = deterministicRandom()->randomInt(0, 4);
 	// Continuously re-pick the storage engine type if it's the one we want to exclude
-	while (storage_engine_type == testConfig.storageEngineExcludeType) {
+	while (std::find(testConfig.storageEngineExcludeTypes.begin(),
+	                 testConfig.storageEngineExcludeTypes.end(),
+	                 storage_engine_type) != testConfig.storageEngineExcludeTypes.end()) {
 		storage_engine_type = deterministicRandom()->randomInt(0, 4);
 	}
 	switch (storage_engine_type) {
@@ -989,11 +994,11 @@ void SimulationConfig::generateNormalConfig(const TestConfig& testConfig) {
 	if (deterministicRandom()->random01() < 0.5) {
 		int logSpill = deterministicRandom()->randomInt(TLogSpillType::VALUE, TLogSpillType::END);
 		set_config(format("log_spill:=%d", logSpill));
-		int logVersion = deterministicRandom()->randomInt(TLogVersion::MIN_RECRUITABLE, TLogVersion::MAX_SUPPORTED + 1);
+		int logVersion = deterministicRandom()->randomInt(TLogVersion::MIN_RECRUITABLE, testConfig.maxTLogVersion + 1);
 		set_config(format("log_version:=%d", logVersion));
 	} else {
 		if (deterministicRandom()->random01() < 0.7)
-			set_config(format("log_version:=%d", TLogVersion::MAX_SUPPORTED));
+			set_config(format("log_version:=%d", testConfig.maxTLogVersion));
 		if (deterministicRandom()->random01() < 0.5)
 			set_config(format("log_spill:=%d", TLogSpillType::DEFAULT));
 	}
@@ -1663,8 +1668,17 @@ void checkTestConf(const char* testFile, TestConfig* testConfig) {
 			sscanf(value.c_str(), "%d", &testConfig->logAntiQuorum);
 		}
 
-		if (attrib == "storageEngineExcludeType") {
-			sscanf(value.c_str(), "%d", &testConfig->storageEngineExcludeType);
+		if (attrib == "storageEngineExcludeTypes") {
+			std::stringstream ss(value);
+			for (int i; ss >> i;) {
+				testConfig->storageEngineExcludeTypes.push_back(i);
+				if (ss.peek() == ',') {
+					ss.ignore();
+				}
+			}
+		}
+		if (attrib == "maxTLogVersion") {
+			sscanf(value.c_str(), "%d", &testConfig->maxTLogVersion);
 		}
 	}
 

fdbserver/TesterInterface.actor.h

@@ -29,6 +29,7 @@
 #include "fdbrpc/fdbrpc.h"
 #include "fdbrpc/PerfMetric.h"
 #include "fdbclient/NativeAPI.actor.h"
+#include "flow/UnitTest.h"
 #include "flow/actorcompiler.h" // has to be last include
 struct CheckReply {
 	constexpr static FileIdentifier file_identifier = 11;
@@ -109,12 +110,15 @@ struct TestConfig {
 	bool startIncompatibleProcess = false;
 	int logAntiQuorum = -1;
 	// Storage Engine Types: Verify match with SimulationConfig::generateNormalConfig
-	//	-1 = None
 	//	0 = "ssd"
 	//	1 = "memory"
 	//	2 = "memory-radixtree-beta"
 	//	3 = "ssd-redwood-experimental"
-	int storageEngineExcludeType = -1;
+	// Requires a comma-separated list of numbers WITHOUT whitespaces
+	std::vector<int> storageEngineExcludeTypes;
+	// Set the maximum TLog version that can be selected for a test
+	// Refer to FDBTypes.h::TLogVersion. Defaults to the maximum supported version.
+	int maxTLogVersion = TLogVersion::MAX_SUPPORTED;
 };
 
 struct TesterInterface {
@@ -135,7 +139,7 @@ ACTOR Future<Void> testerServerCore(TesterInterface interf,
                                     LocalityData locality);
 
 enum test_location_t { TEST_HERE, TEST_ON_SERVERS, TEST_ON_TESTERS };
-enum test_type_t { TEST_TYPE_FROM_FILE, TEST_TYPE_CONSISTENCY_CHECK };
+enum test_type_t { TEST_TYPE_FROM_FILE, TEST_TYPE_CONSISTENCY_CHECK, TEST_TYPE_UNIT_TESTS };
 
 ACTOR Future<Void> runTests(Reference<ClusterConnectionFile> connFile,
                             test_type_t whatToRun,
@@ -143,7 +147,8 @@ ACTOR Future<Void> runTests(Reference<ClusterConnectionFile> connFile,
                             int minTestersExpected,
                             std::string fileName = std::string(),
                             StringRef startingConfiguration = StringRef(),
-                            LocalityData locality = LocalityData());
+                            LocalityData locality = LocalityData(),
+                            UnitTestParameters testOptions = UnitTestParameters());
 
 #include "flow/unactorcompiler.h"
 #endif

fdbserver/VersionedBTree.actor.cpp

@@ -6956,7 +6956,7 @@ RedwoodRecordRef randomRedwoodRecordRef(const std::string& keyBuffer, const std:
 	return rec;
 }
 
-TEST_CASE("!/redwood/correctness/unit/RedwoodRecordRef") {
+TEST_CASE("/redwood/correctness/unit/RedwoodRecordRef") {
 	ASSERT(RedwoodRecordRef::Delta::LengthFormatSizes[0] == 3);
 	ASSERT(RedwoodRecordRef::Delta::LengthFormatSizes[1] == 4);
 	ASSERT(RedwoodRecordRef::Delta::LengthFormatSizes[2] == 6);
@@ -7029,7 +7029,7 @@ TEST_CASE("!/redwood/correctness/unit/RedwoodRecordRef") {
 		bytes += deltaTest(a, b);
 	}
 	double elapsed = timer() - start;
-	printf("DeltaTest() on random large records %g M/s  %g MB/s\n", count / elapsed / 1e6, bytes / elapsed / 1e6);
+	printf("DeltaTest() on random large records %f M/s  %f MB/s\n", count / elapsed / 1e6, bytes / elapsed / 1e6);
 
 	keyBuffer.resize(30);
 	valueBuffer.resize(100);
@@ -7041,7 +7041,7 @@ TEST_CASE("!/redwood/correctness/unit/RedwoodRecordRef") {
 		RedwoodRecordRef b = randomRedwoodRecordRef(keyBuffer, valueBuffer);
 		bytes += deltaTest(a, b);
 	}
-	printf("DeltaTest() on random small records %g M/s  %g MB/s\n", count / elapsed / 1e6, bytes / elapsed / 1e6);
+	printf("DeltaTest() on random small records %f M/s  %f MB/s\n", count / elapsed / 1e6, bytes / elapsed / 1e6);
 
 	RedwoodRecordRef rec1;
 	RedwoodRecordRef rec2;
@@ -7058,7 +7058,7 @@ TEST_CASE("!/redwood/correctness/unit/RedwoodRecordRef") {
 	for (i = 0; i < count; ++i) {
 		total += rec1.getCommonPrefixLen(rec2, 50);
 	}
-	printf("%" PRId64 " getCommonPrefixLen(skip=50) %g M/s\n", total, count / (timer() - start) / 1e6);
+	printf("%" PRId64 " getCommonPrefixLen(skip=50) %f M/s\n", total, count / (timer() - start) / 1e6);
 
 	start = timer();
 	total = 0;
@@ -7066,7 +7066,7 @@ TEST_CASE("!/redwood/correctness/unit/RedwoodRecordRef") {
 	for (i = 0; i < count; ++i) {
 		total += rec1.getCommonPrefixLen(rec2, 0);
 	}
-	printf("%" PRId64 " getCommonPrefixLen(skip=0) %g M/s\n", total, count / (timer() - start) / 1e6);
+	printf("%" PRId64 " getCommonPrefixLen(skip=0) %f M/s\n", total, count / (timer() - start) / 1e6);
 
 	char buf[1000];
 	RedwoodRecordRef::Delta& d = *(RedwoodRecordRef::Delta*)buf;
@@ -7079,7 +7079,7 @@ TEST_CASE("!/redwood/correctness/unit/RedwoodRecordRef") {
 	for (i = 0; i < count; ++i) {
 		total += rec1.writeDelta(d, rec2, commonPrefix);
 	}
-	printf("%" PRId64 " writeDelta(commonPrefix=%d) %g M/s\n", total, commonPrefix, count / (timer() - start) / 1e6);
+	printf("%" PRId64 " writeDelta(commonPrefix=%d) %f M/s\n", total, commonPrefix, count / (timer() - start) / 1e6);
 
 	start = timer();
 	total = 0;
@@ -7087,12 +7087,12 @@ TEST_CASE("!/redwood/correctness/unit/RedwoodRecordRef") {
 	for (i = 0; i < count; ++i) {
 		total += rec1.writeDelta(d, rec2);
 	}
-	printf("%" PRId64 " writeDelta() %g M/s\n", total, count / (timer() - start) / 1e6);
+	printf("%" PRId64 " writeDelta() %f M/s\n", total, count / (timer() - start) / 1e6);
 
 	return Void();
 }
 
-TEST_CASE("!/redwood/correctness/unit/deltaTree/RedwoodRecordRef") {
+TEST_CASE("/redwood/correctness/unit/deltaTree/RedwoodRecordRef") {
 	// Sanity check on delta tree node format
 	ASSERT(DeltaTree<RedwoodRecordRef>::Node::headerSize(false) == 4);
 	ASSERT(DeltaTree<RedwoodRecordRef>::Node::headerSize(true) == 8);
@@ -7271,7 +7271,7 @@ TEST_CASE("!/redwood/correctness/unit/deltaTree/RedwoodRecordRef") {
 	return Void();
 }
 
-TEST_CASE("!/redwood/correctness/unit/deltaTree/IntIntPair") {
+TEST_CASE("/redwood/correctness/unit/deltaTree/IntIntPair") {
 	const int N = 200;
 	IntIntPair prev = { 1, 0 };
 	IntIntPair next = { 10000, 10000 };
@@ -7615,7 +7615,7 @@ struct SimpleCounter {
 	std::string toString() { return format("%" PRId64 "/%.2f/%.2f", x, rate() / 1e6, avgRate() / 1e6); }
 };
 
-TEST_CASE("!/redwood/performance/mutationBuffer") {
+TEST_CASE(":/redwood/performance/mutationBuffer") {
 	// This test uses pregenerated short random keys
 	int count = 10e6;
 
@@ -7643,34 +7643,47 @@ TEST_CASE("!/redwood/performance/mutationBuffer") {
 	return Void();
 }
 
-TEST_CASE("!/redwood/correctness/btree") {
+TEST_CASE("/redwood/correctness/btree") {
 	g_redwoodMetricsActor = Void(); // Prevent trace event metrics from starting
 	g_redwoodMetrics.clear();
 
-	state std::string pagerFile = "unittest_pageFile.redwood";
+	state std::string fileName = params.get("fileName").orDefault("unittest_pageFile.redwood");
 	IPager2* pager;
 
-	state bool serialTest = deterministicRandom()->coinflip();
-	state bool shortTest = deterministicRandom()->coinflip();
+	state bool serialTest = params.getInt("serialTest").orDefault(deterministicRandom()->coinflip());
+	state bool shortTest = params.getInt("shortTest").orDefault(deterministicRandom()->coinflip());
 
 	state int pageSize =
 	    shortTest ? 200 : (deterministicRandom()->coinflip() ? 4096 : deterministicRandom()->randomInt(200, 400));
 
-	state int64_t targetPageOps = shortTest ? 50000 : 1000000;
-	state bool pagerMemoryOnly = shortTest && (deterministicRandom()->random01() < .001);
-	state int maxKeySize = deterministicRandom()->randomInt(1, pageSize * 2);
-	state int maxValueSize = randomSize(pageSize * 25);
-	state int maxCommitSize = shortTest ? 1000 : randomSize(std::min<int>((maxKeySize + maxValueSize) * 20000, 10e6));
-	state double clearProbability = deterministicRandom()->random01() * .1;
-	state double clearSingleKeyProbability = deterministicRandom()->random01();
-	state double clearPostSetProbability = deterministicRandom()->random01() * .1;
-	state double coldStartProbability = pagerMemoryOnly ? 0 : (deterministicRandom()->random01() * 0.3);
-	state double advanceOldVersionProbability = deterministicRandom()->random01();
+	state int64_t targetPageOps = params.getInt("targetPageOps").orDefault(shortTest ? 50000 : 1000000);
+	state bool pagerMemoryOnly =
+	    params.getInt("pagerMemoryOnly").orDefault(shortTest && (deterministicRandom()->random01() < .001));
+	state int maxKeySize = params.getInt("maxKeySize").orDefault(deterministicRandom()->randomInt(1, pageSize * 2));
+	state int maxValueSize = params.getInt("maxValueSize").orDefault(randomSize(pageSize * 25));
+	state int maxCommitSize =
+	    params.getInt("maxCommitSize")
+	        .orDefault(shortTest ? 1000 : randomSize(std::min<int>((maxKeySize + maxValueSize) * 20000, 10e6)));
+	state double clearProbability =
+	    params.getDouble("clearProbability").orDefault(deterministicRandom()->random01() * .1);
+	state double clearSingleKeyProbability =
+	    params.getDouble("clearSingleKeyProbability").orDefault(deterministicRandom()->random01());
+	state double clearPostSetProbability =
+	    params.getDouble("clearPostSetProbability").orDefault(deterministicRandom()->random01() * .1);
+	state double coldStartProbability = params.getDouble("coldStartProbability")
+	                                        .orDefault(pagerMemoryOnly ? 0 : (deterministicRandom()->random01() * 0.3));
+	state double advanceOldVersionProbability =
+	    params.getDouble("advanceOldVersionProbability").orDefault(deterministicRandom()->random01());
 	state int64_t cacheSizeBytes =
-	    pagerMemoryOnly ? 2e9 : (pageSize * deterministicRandom()->randomInt(1, (BUGGIFY ? 2 : 10000) + 1));
-	state Version versionIncrement = deterministicRandom()->randomInt64(1, 1e8);
-	state Version remapCleanupWindow = BUGGIFY ? 0 : deterministicRandom()->randomInt64(1, versionIncrement * 50);
-	state int maxVerificationMapEntries = 300e3;
+	    params.getInt("cacheSizeBytes")
+	        .orDefault(pagerMemoryOnly ? 2e9
+	                                   : (pageSize * deterministicRandom()->randomInt(1, (BUGGIFY ? 2 : 10000) + 1)));
+	state Version versionIncrement =
+	    params.getInt("versionIncrement").orDefault(deterministicRandom()->randomInt64(1, 1e8));
+	state Version remapCleanupWindow =
+	    params.getInt("remapCleanupWindow")
+	        .orDefault(BUGGIFY ? 0 : deterministicRandom()->randomInt64(1, versionIncrement * 50));
+	state int maxVerificationMapEntries = params.getInt("maxVerificationMapEntries").orDefault(300e3);
 
 	printf("\n");
 	printf("targetPageOps: %" PRId64 "\n", targetPageOps);
@@ -7693,11 +7706,11 @@ TEST_CASE("!/redwood/correctness/btree") {
 	printf("\n");
 
 	printf("Deleting existing test data...\n");
-	deleteFile(pagerFile);
+	deleteFile(fileName);
 
 	printf("Initializing...\n");
-	pager = new DWALPager(pageSize, pagerFile, cacheSizeBytes, remapCleanupWindow, pagerMemoryOnly);
-	state VersionedBTree* btree = new VersionedBTree(pager, pagerFile);
+	pager = new DWALPager(pageSize, fileName, cacheSizeBytes, remapCleanupWindow, pagerMemoryOnly);
+	state VersionedBTree* btree = new VersionedBTree(pager, fileName);
 	wait(btree->init());
 
 	state std::map<std::pair<std::string, Version>, Optional<std::string>> written;
@@ -7900,8 +7913,8 @@ TEST_CASE("!/redwood/correctness/btree") {
 				wait(closedFuture);
 
 				printf("Reopening btree from disk.\n");
-				IPager2* pager = new DWALPager(pageSize, pagerFile, cacheSizeBytes, remapCleanupWindow);
-				btree = new VersionedBTree(pager, pagerFile);
+				IPager2* pager = new DWALPager(pageSize, fileName, cacheSizeBytes, remapCleanupWindow);
+				btree = new VersionedBTree(pager, fileName);
 				wait(btree->init());
 
 				Version v = btree->getLatestVersion();
@@ -7937,7 +7950,7 @@ TEST_CASE("!/redwood/correctness/btree") {
 	state Future<Void> closedFuture = btree->onClosed();
 	btree->close();
 	wait(closedFuture);
-	btree = new VersionedBTree(new DWALPager(pageSize, pagerFile, cacheSizeBytes, 0), pagerFile);
+	btree = new VersionedBTree(new DWALPager(pageSize, fileName, cacheSizeBytes, 0), fileName);
 	wait(btree->init());
 
 	wait(btree->clearAllAndCheckSanity());
@@ -8003,7 +8016,7 @@ ACTOR Future<Void> randomScans(VersionedBTree* btree,
 	return Void();
 }
 
-TEST_CASE("!/redwood/correctness/pager/cow") {
+TEST_CASE(":/redwood/correctness/pager/cow") {
 	state std::string pagerFile = "unittest_pageFile.redwood";
 	printf("Deleting old test data\n");
 	deleteFile(pagerFile);
@@ -8030,7 +8043,7 @@ TEST_CASE("!/redwood/correctness/pager/cow") {
 	return Void();
 }
 
-TEST_CASE("!/redwood/performance/set") {
+TEST_CASE(":/redwood/performance/set") {
 	state SignalableActorCollection actors;
 
 	g_redwoodMetricsActor = Void(); // Prevent trace event metrics from starting
@@ -8045,21 +8058,22 @@ TEST_CASE("!/redwood/performance/set") {
 		deleteFile(pagerFile);
 	}
 
-	state int pageSize = SERVER_KNOBS->REDWOOD_DEFAULT_PAGE_SIZE;
-	state int64_t pageCacheBytes = FLOW_KNOBS->PAGE_CACHE_4K;
-	state int nodeCount = 1e9;
-	state int maxRecordsPerCommit = 20000;
-	state int maxKVBytesPerCommit = 20e6;
-	state int64_t kvBytesTarget = 4e9;
-	state int minKeyPrefixBytes = 25;
-	state int maxKeyPrefixBytes = 25;
-	state int minValueSize = 100;
-	state int maxValueSize = 500;
-	state int minConsecutiveRun = 1;
-	state int maxConsecutiveRun = 100000;
-	state char firstKeyChar = 'a';
-	state char lastKeyChar = 'm';
-	state Version remapCleanupWindow = SERVER_KNOBS->REDWOOD_REMAP_CLEANUP_WINDOW;
+	state int pageSize = params.getInt("pageSize").orDefault(SERVER_KNOBS->REDWOOD_DEFAULT_PAGE_SIZE);
+	state int64_t pageCacheBytes = params.getInt("pageCacheBytes").orDefault(FLOW_KNOBS->PAGE_CACHE_4K);
+	state int nodeCount = params.getInt("nodeCount").orDefault(1e9);
+	state int maxRecordsPerCommit = params.getInt("maxRecordsPerCommit").orDefault(20000);
+	state int maxKVBytesPerCommit = params.getInt("maxKVBytesPerCommit").orDefault(20e6);
+	state int64_t kvBytesTarget = params.getInt("kvBytesTarget").orDefault(4e9);
+	state int minKeyPrefixBytes = params.getInt("minKeyPrefixBytes").orDefault(25);
+	state int maxKeyPrefixBytes = params.getInt("maxKeyPrefixBytes").orDefault(25);
+	state int minValueSize = params.getInt("minValueSize").orDefault(100);
+	state int maxValueSize = params.getInt("maxValueSize").orDefault(500);
+	state int minConsecutiveRun = params.getInt("minConsecutiveRun").orDefault(1);
+	state int maxConsecutiveRun = params.getInt("maxConsecutiveRun").orDefault(100);
+	state char firstKeyChar = params.get("firstKeyChar").orDefault("a")[0];
+	state char lastKeyChar = params.get("lastKeyChar").orDefault("m")[0];
+	state Version remapCleanupWindow =
+	    params.getInt("remapCleanupWindow").orDefault(SERVER_KNOBS->REDWOOD_REMAP_CLEANUP_WINDOW);
 
 	printf("pageSize: %d\n", pageSize);
 	printf("pageCacheBytes: %" PRId64 "\n", pageCacheBytes);
@@ -8541,11 +8555,11 @@ ACTOR Future<Void> doPrefixInsertComparison(int suffixSize,
 	return Void();
 }
 
-TEST_CASE("!/redwood/performance/prefixSizeComparison") {
-	state int suffixSize = 12;
-	state int valueSize = 100;
-	state int recordCountTarget = 100e6;
-	state int usePrefixesInOrder = false;
+TEST_CASE(":/redwood/performance/prefixSizeComparison") {
+	state int suffixSize = params.getInt("suffixSize").orDefault(12);
+	state int valueSize = params.getInt("valueSize").orDefault(100);
+	state int recordCountTarget = params.getInt("recordCountTarget").orDefault(100e6);
+	state bool usePrefixesInOrder = params.getInt("usePrefixesInOrder").orDefault(0);
 
 	wait(doPrefixInsertComparison(
 	    suffixSize, valueSize, recordCountTarget, usePrefixesInOrder, KVSource({ { 10, 100000 } })));
@@ -8562,10 +8576,10 @@ TEST_CASE("!/redwood/performance/prefixSizeComparison") {
 	return Void();
 }
 
-TEST_CASE("!/redwood/performance/sequentialInsert") {
-	state int prefixLen = 30;
-	state int valueSize = 100;
-	state int recordCountTarget = 100e6;
+TEST_CASE(":/redwood/performance/sequentialInsert") {
+	state int prefixLen = params.getInt("prefixLen").orDefault(30);
+	state int valueSize = params.getInt("valueSize").orDefault(100);
+	state int recordCountTarget = params.getInt("recordCountTarget").orDefault(100e6);
 
 	deleteFile("test.redwood");
 	wait(delay(5));

fdbserver/fdbserver.actor.cpp

@@ -67,6 +67,7 @@
 #include "flow/TLSConfig.actor.h"
 #include "flow/Tracing.h"
 #include "flow/WriteOnlySet.h"
+#include "flow/UnitTest.h"
 
 #if defined(__linux__) || defined(__FreeBSD__)
 #include <execinfo.h>
@@ -89,7 +90,7 @@ enum {
 	OPT_CONNFILE, OPT_SEEDCONNFILE, OPT_SEEDCONNSTRING, OPT_ROLE, OPT_LISTEN, OPT_PUBLICADDR, OPT_DATAFOLDER, OPT_LOGFOLDER, OPT_PARENTPID, OPT_TRACER, OPT_NEWCONSOLE,
 	OPT_NOBOX, OPT_TESTFILE, OPT_RESTARTING, OPT_RESTORING, OPT_RANDOMSEED, OPT_KEY, OPT_MEMLIMIT, OPT_STORAGEMEMLIMIT, OPT_CACHEMEMLIMIT, OPT_MACHINEID,
 	OPT_DCID, OPT_MACHINE_CLASS, OPT_BUGGIFY, OPT_VERSION, OPT_BUILD_FLAGS, OPT_CRASHONERROR, OPT_HELP, OPT_NETWORKIMPL, OPT_NOBUFSTDOUT, OPT_BUFSTDOUTERR,
-	OPT_TRACECLOCK, OPT_NUMTESTERS, OPT_DEVHELP, OPT_ROLLSIZE, OPT_MAXLOGS, OPT_MAXLOGSSIZE, OPT_KNOB, OPT_TESTSERVERS, OPT_TEST_ON_SERVERS, OPT_METRICSCONNFILE,
+	OPT_TRACECLOCK, OPT_NUMTESTERS, OPT_DEVHELP, OPT_ROLLSIZE, OPT_MAXLOGS, OPT_MAXLOGSSIZE, OPT_KNOB, OPT_UNITTESTPARAM, OPT_TESTSERVERS, OPT_TEST_ON_SERVERS, OPT_METRICSCONNFILE,
 	OPT_METRICSPREFIX, OPT_LOGGROUP, OPT_LOCALITY, OPT_IO_TRUST_SECONDS, OPT_IO_TRUST_WARN_ONLY, OPT_FILESYSTEM, OPT_PROFILER_RSS_SIZE, OPT_KVFILE,
 	OPT_TRACE_FORMAT, OPT_WHITELIST_BINPATH, OPT_BLOB_CREDENTIAL_FILE
 };
@@ -163,6 +164,7 @@ CSimpleOpt::SOption g_rgOptions[] = {
 	{ OPT_HELP,                  "--help",                      SO_NONE },
 	{ OPT_DEVHELP,               "--dev-help",                  SO_NONE },
 	{ OPT_KNOB,                  "--knob_",                     SO_REQ_SEP },
+	{ OPT_UNITTESTPARAM,         "--test_",                     SO_REQ_SEP },
 	{ OPT_LOCALITY,              "--locality_",                 SO_REQ_SEP },
 	{ OPT_TESTSERVERS,           "--testservers",               SO_REQ_SEP },
 	{ OPT_TEST_ON_SERVERS,       "--testonservers",             SO_NONE },
@@ -623,16 +625,19 @@ static void printUsage(const char* name, bool devhelp) {
 	printOptionUsage("-h, -?, --help", "Display this help and exit.");
 	if (devhelp) {
 		printf("  --build_flags  Print build information and exit.\n");
-		printOptionUsage("-r ROLE, --role ROLE",
-		                 " Server role (valid options are fdbd, test, multitest,"
-		                 " simulation, networktestclient, networktestserver, restore"
-		                 " consistencycheck, kvfileintegritycheck, kvfilegeneratesums). The default is `fdbd'.");
+		printOptionUsage(
+		    "-r ROLE, --role ROLE",
+		    " Server role (valid options are fdbd, test, multitest,"
+		    " simulation, networktestclient, networktestserver, restore"
+		    " consistencycheck, kvfileintegritycheck, kvfilegeneratesums, unittests). The default is `fdbd'.");
 #ifdef _WIN32
 		printOptionUsage("-n, --newconsole", " Create a new console.");
 		printOptionUsage("-q, --no_dialog", " Disable error dialog on crash.");
 		printOptionUsage("--parentpid PID", " Specify a process after whose termination to exit.");
 #endif
-		printOptionUsage("-f TESTFILE, --testfile", " Testfile to run, defaults to `tests/default.txt'.");
+		printOptionUsage("-f TESTFILE, --testfile",
+		                 " Testfile to run, defaults to `tests/default.txt'.  If role is `unittests', specifies which "
+		                 "unit tests to run as a search prefix.");
 		printOptionUsage("-R, --restarting", " Restart a previous simulation that was cleanly shut down.");
 		printOptionUsage("-s SEED, --seed SEED", " Random seed.");
 		printOptionUsage("-k KEY, --key KEY", "Target key for search role.");
@@ -652,6 +657,8 @@ static void printUsage(const char* name, bool devhelp) {
 		printOptionUsage("--num_testers NUM",
 		                 " A multitester will wait for NUM testers before starting"
 		                 " (defaults to 1).");
+		printOptionUsage("--test_PARAMNAME PARAMVALUE",
+		                 " Set a UnitTest named parameter to the given value.  Names are case sensitive.");
 #ifdef __linux__
 		printOptionUsage("--rsssize SIZE",
 		                 " Turns on automatic heap profiling when RSS memory size exceeds"
@@ -923,6 +930,7 @@ enum class ServerRole {
 	SkipListTest,
 	Test,
 	VersionedMapTest,
+	UnitTests
 };
 struct CLIOptions {
 	std::string commandLine;
@@ -971,6 +979,7 @@ struct CLIOptions {
 
 	Reference<ClusterConnectionFile> connectionFile;
 	Standalone<StringRef> machineId;
+	UnitTestParameters testParams;
 
 	static CLIOptions parseArgs(int argc, char* argv[]) {
 		CLIOptions opts;
@@ -1045,6 +1054,15 @@ private:
 				knobs.push_back(std::make_pair(syn, args.OptionArg()));
 				break;
 			}
+			case OPT_UNITTESTPARAM: {
+				std::string syn = args.OptionSyntax();
+				if (!StringRef(syn).startsWith(LiteralStringRef("--test_"))) {
+					fprintf(stderr, "ERROR: unable to parse knob option '%s'\n", syn.c_str());
+					flushAndExit(FDB_EXIT_ERROR);
+				}
+				testParams.set(syn.substr(7), args.OptionArg());
+				break;
+			}
 			case OPT_LOCALITY: {
 				std::string syn = args.OptionSyntax();
 				if (!StringRef(syn).startsWith(LiteralStringRef("--locality_"))) {
@@ -1103,6 +1121,8 @@ private:
 					role = ServerRole::KVFileGenerateIOLogChecksums;
 				else if (!strcmp(sRole, "consistencycheck"))
 					role = ServerRole::ConsistencyCheck;
+				else if (!strcmp(sRole, "unittests"))
+					role = ServerRole::UnitTests;
 				else {
 					fprintf(stderr, "ERROR: Unknown role `%s'\n", sRole);
 					printHelpTeaser(argv[0]);
@@ -1462,7 +1482,8 @@ private:
 			    return StringRef(addr).startsWith(LiteralStringRef("auto:"));
 		    });
 		if ((role != ServerRole::Simulation && role != ServerRole::CreateTemplateDatabase &&
-		     role != ServerRole::KVFileIntegrityCheck && role != ServerRole::KVFileGenerateIOLogChecksums) ||
+		     role != ServerRole::KVFileIntegrityCheck && role != ServerRole::KVFileGenerateIOLogChecksums &&
+		     role != ServerRole::UnitTests) ||
 		    autoPublicAddress) {
 
 			if (seedSpecified && !fileExists(connFile)) {
@@ -1999,6 +2020,18 @@ int main(int argc, char* argv[]) {
 			                       StringRef(),
 			                       opts.localities));
 			g_network->run();
+		} else if (role == ServerRole::UnitTests) {
+			setupRunLoopProfiler();
+			auto m = startSystemMonitor(opts.dataFolder, opts.dcId, opts.zoneId, opts.zoneId);
+			f = stopAfter(runTests(opts.connectionFile,
+			                       TEST_TYPE_UNIT_TESTS,
+			                       TEST_HERE,
+			                       1,
+			                       opts.testFile,
+			                       StringRef(),
+			                       opts.localities,
+			                       opts.testParams));
+			g_network->run();
 		} else if (role == ServerRole::CreateTemplateDatabase) {
 			createTemplateDatabase();
 		} else if (role == ServerRole::NetworkTestClient) {

fdbserver/networktest.actor.cpp

@@ -517,13 +517,6 @@ struct P2PNetworkTest {
 		       self->listeners.size(),
 		       self->remotes.size(),
 		       self->connectionsOut);
-		printf("Request size: %s\n", self->requestBytes.toString().c_str());
-		printf("Response size: %s\n", self->replyBytes.toString().c_str());
-		printf("Requests per outgoing session: %d\n", self->requests.toString().c_str());
-		printf("Delay before socket read: %s\n", self->waitReadMilliseconds.toString().c_str());
-		printf("Delay before socket write: %s\n", self->waitWriteMilliseconds.toString().c_str());
-		printf("Delay before session close: %s\n", self->idleMilliseconds.toString().c_str());
-		printf("Send/Recv size %d bytes\n", FLOW_KNOBS->MAX_PACKET_SEND_BYTES);
 
 		for (auto n : self->remotes) {
 			printf("Remote: %s\n", n.toString().c_str());
@@ -534,6 +527,19 @@ struct P2PNetworkTest {
 			actors.add(incoming(self, el));
 		}
 
+		printf("Request size: %s\n", self->requestBytes.toString().c_str());
+		printf("Response size: %s\n", self->replyBytes.toString().c_str());
+		printf("Requests per outgoing session: %s\n", self->requests.toString().c_str());
+		printf("Delay before socket read: %s\n", self->waitReadMilliseconds.toString().c_str());
+		printf("Delay before socket write: %s\n", self->waitWriteMilliseconds.toString().c_str());
+		printf("Delay before session close: %s\n", self->idleMilliseconds.toString().c_str());
+		printf("Send/Recv size %d bytes\n", FLOW_KNOBS->MAX_PACKET_SEND_BYTES);
+
+		if ((self->remotes.empty() || self->connectionsOut == 0) && self->listeners.empty()) {
+			printf("No listeners and no remotes or connectionsOut, so there is nothing to do!\n");
+			ASSERT((!self->remotes.empty() && (self->connectionsOut > 0)) || !self->listeners.empty());
+		}
+
 		if (!self->remotes.empty()) {
 			for (int i = 0; i < self->connectionsOut; ++i) {
 				actors.add(outgoing(self));
@@ -549,27 +555,30 @@ struct P2PNetworkTest {
 	Future<Void> run() { return run_impl(this); }
 };
 
-int getEnvInt(const char* name, int defaultValue = 0) {
-	const char* val = getenv(name);
-	return val != nullptr ? atol(val) : defaultValue;
-}
-
-std::string getEnvStr(const char* name, std::string defaultValue = "") {
-	const char* val = getenv(name);
-	return val != nullptr ? val : defaultValue;
-}
-
-// TODO: Remove this hacky thing and make a "networkp2ptest" role in fdbserver
-TEST_CASE("!p2ptest") {
-	state P2PNetworkTest p2p(getEnvStr("listenerAddresses", ""),
-	                         getEnvStr("remoteAddresses", ""),
-	                         getEnvInt("connectionsOut", 0),
-	                         getEnvStr("requestBytes", "0"),
-	                         getEnvStr("replyBytes", "0"),
-	                         getEnvStr("requests", "0"),
-	                         getEnvStr("idleMilliseconds", "0"),
-	                         getEnvStr("waitReadMilliseconds", "0"),
-	                         getEnvStr("waitWriteMilliseconds", "0"));
+// Peer-to-Peer network test.
+// One or more instances can be run and set to talk to each other.
+// Each instance
+//   - listens on 0 or more listenerAddresses
+//   - maintains 0 or more connectionsOut at a time, each to a random choice from remoteAddresses
+// Address lists are a string of comma-separated IP:port[:tls] strings.
+//
+// The other arguments can be specified as "fixedValue" or "minValue:maxValue".
+// Each outgoing connection will live for a random requests count.
+// Each request will
+//   - send a random requestBytes sized message
+//   - wait for a random replyBytes sized response.
+// The client will close the connection after a random idleMilliseconds.
+// Reads and writes can optionally preceded by random delays, waitReadMilliseconds and waitWriteMilliseconds.
+TEST_CASE(":/network/p2ptest") {
+	state P2PNetworkTest p2p(params.get("listenerAddresses").orDefault(""),
+	                         params.get("remoteAddresses").orDefault(""),
+	                         params.getInt("connectionsOut").orDefault(1),
+	                         params.get("requestBytes").orDefault("50:100"),
+	                         params.get("replyBytes").orDefault("500:1000"),
+	                         params.get("requests").orDefault("10:10000"),
+	                         params.get("idleMilliseconds").orDefault("0"),
+	                         params.get("waitReadMilliseconds").orDefault("0"),
+	                         params.get("waitWriteMilliseconds").orDefault("0"));
 
 	wait(p2p.run());
 	return Void();

fdbserver/tester.actor.cpp

@@ -763,7 +763,7 @@ ACTOR Future<DistributedTestResults> runWorkload(Database cx, std::vector<Tester
 		req.title = spec.title;
 		req.useDatabase = spec.useDB;
 		req.timeout = spec.timeout;
-		req.databasePingDelay = spec.databasePingDelay;
+		req.databasePingDelay = spec.useDB ? spec.databasePingDelay : 0.0;
 		req.options = spec.options;
 		req.clientId = i;
 		req.clientCount = testers.size();
@@ -1036,8 +1036,10 @@ std::map<std::string, std::function<void(const std::string&)>> testSpecGlobalKey
 	  } },
 	{ "startIncompatibleProcess",
 	  [](const std::string& value) { TraceEvent("TestParserTest").detail("ParsedStartIncompatibleProcess", value); } },
-	{ "storageEngineExcludeType",
-	  [](const std::string& value) { TraceEvent("TestParserTest").detail("ParsedStorageEngineExcludeType", ""); } }
+	{ "storageEngineExcludeTypes",
+	  [](const std::string& value) { TraceEvent("TestParserTest").detail("ParsedStorageEngineExcludeTypes", ""); } },
+	{ "maxTLogVersion",
+	  [](const std::string& value) { TraceEvent("TestParserTest").detail("ParsedMaxTLogVersion", ""); } }
 };
 
 std::map<std::string, std::function<void(const std::string& value, TestSpec* spec)>> testSpecTestKeys = {
@@ -1572,13 +1574,16 @@ ACTOR Future<Void> runTests(Reference<ClusterConnectionFile> connFile,
                             int minTestersExpected,
                             std::string fileName,
                             StringRef startingConfiguration,
-                            LocalityData locality) {
+                            LocalityData locality,
+                            UnitTestParameters testOptions) {
 	state vector<TestSpec> testSpecs;
 	auto cc = makeReference<AsyncVar<Optional<ClusterControllerFullInterface>>>();
 	auto ci = makeReference<AsyncVar<Optional<ClusterInterface>>>();
 	vector<Future<Void>> actors;
-	actors.push_back(reportErrors(monitorLeader(connFile, cc), "MonitorLeader"));
-	actors.push_back(reportErrors(extractClusterInterface(cc, ci), "ExtractClusterInterface"));
+	if (connFile) {
+		actors.push_back(reportErrors(monitorLeader(connFile, cc), "MonitorLeader"));
+		actors.push_back(reportErrors(extractClusterInterface(cc, ci), "ExtractClusterInterface"));
+	}
 
 	if (whatToRun == TEST_TYPE_CONSISTENCY_CHECK) {
 		TestSpec spec;
@@ -1603,6 +1608,22 @@ ACTOR Future<Void> runTests(Reference<ClusterConnectionFile> connFile,
 		                       KeyValueRef(LiteralStringRef("shuffleShards"), LiteralStringRef("true")));
 		spec.options.push_back_deep(spec.options.arena(), options);
 		testSpecs.push_back(spec);
+	} else if (whatToRun == TEST_TYPE_UNIT_TESTS) {
+		TestSpec spec;
+		Standalone<VectorRef<KeyValueRef>> options;
+		spec.title = LiteralStringRef("UnitTests");
+		spec.startDelay = 0;
+		spec.useDB = false;
+		spec.timeout = 0;
+		options.push_back_deep(options.arena(),
+		                       KeyValueRef(LiteralStringRef("testName"), LiteralStringRef("UnitTests")));
+		options.push_back_deep(options.arena(), KeyValueRef(LiteralStringRef("testsMatching"), fileName));
+		// Add unit test options as test spec options
+		for (auto& kv : testOptions.params) {
+			options.push_back_deep(options.arena(), KeyValueRef(kv.first, kv.second));
+		}
+		spec.options.push_back_deep(spec.options.arena(), options);
+		testSpecs.push_back(spec);
 	} else {
 		ifstream ifs;
 		ifs.open(fileName.c_str(), ifstream::in);

fdbserver/workloads/ClientTransactionProfileCorrectness.actor.cpp

@@ -1,5 +1,6 @@
 #include "fdbserver/workloads/workloads.actor.h"
 #include "fdbserver/ServerDBInfo.h"
+#include "fdbclient/GlobalConfig.actor.h"
 #include "fdbclient/ManagementAPI.actor.h"
 #include "fdbclient/RunTransaction.actor.h"
 #include "flow/actorcompiler.h" // has to be last include
@@ -269,10 +270,12 @@ struct ClientTransactionProfileCorrectnessWorkload : TestWorkload {
 	ACTOR Future<Void> changeProfilingParameters(Database cx, int64_t sizeLimit, double sampleProbability) {
 
 		wait(runRYWTransaction(cx, [=](Reference<ReadYourWritesTransaction> tr) -> Future<Void> {
-			tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
+			tr->setOption(FDBTransactionOptions::SPECIAL_KEY_SPACE_ENABLE_WRITES);
 			tr->setOption(FDBTransactionOptions::LOCK_AWARE);
-			tr->set(fdbClientInfoTxnSampleRate, BinaryWriter::toValue(sampleProbability, Unversioned()));
-			tr->set(fdbClientInfoTxnSizeLimit, BinaryWriter::toValue(sizeLimit, Unversioned()));
+			Tuple rate = Tuple().appendDouble(sampleProbability);
+			Tuple size = Tuple().append(sizeLimit);
+			tr->set(GlobalConfig::prefixedKey(fdbClientInfoTxnSampleRate), rate.pack());
+			tr->set(GlobalConfig::prefixedKey(fdbClientInfoTxnSizeLimit), size.pack());
 			return Void();
 		}));
 		return Void();

fdbserver/workloads/SpecialKeySpaceCorrectness.actor.cpp

@@ -21,6 +21,7 @@
 #include "boost/lexical_cast.hpp"
 #include "boost/algorithm/string.hpp"
 
+#include "fdbclient/GlobalConfig.actor.h"
 #include "fdbclient/ManagementAPI.actor.h"
 #include "fdbclient/NativeAPI.actor.h"
 #include "fdbclient/ReadYourWrites.h"

fdbserver/workloads/UnitTests.actor.cpp

@@ -34,6 +34,7 @@ struct UnitTestWorkload : TestWorkload {
 	bool enabled;
 	std::string testPattern;
 	int testRunLimit;
+	UnitTestParameters testParams;
 
 	PerfIntCounter testsAvailable, testsExecuted, testsFailed;
 	PerfDoubleCounter totalWallTime, totalSimTime;
@@ -45,6 +46,14 @@ struct UnitTestWorkload : TestWorkload {
 		enabled = !clientId; // only do this on the "first" client
 		testPattern = getOption(options, LiteralStringRef("testsMatching"), Value()).toString();
 		testRunLimit = getOption(options, LiteralStringRef("maxTestCases"), -1);
+
+		// Consume all remaining options as testParams which the unit test can access
+		for (auto& kv : options) {
+			if (kv.value.size() != 0) {
+				testParams.set(kv.key.toString(), getOption(options, kv.key, StringRef()).toString());
+			}
+		}
+
 		forceLinkIndexedSetTests();
 		forceLinkDequeTests();
 		forceLinkFlowTests();
@@ -94,7 +103,7 @@ struct UnitTestWorkload : TestWorkload {
 			state double start_timer = timer();
 
 			try {
-				wait(test->func());
+				wait(test->func(self->testParams));
 			} catch (Error& e) {
 				++self->testsFailed;
 				result = e;

flow/Knobs.cpp

@@ -135,6 +135,7 @@ void FlowKnobs::initialize(bool randomize, bool isSimulated) {
 	init( DISABLE_POSIX_KERNEL_AIO,                              0 );
 
 	//AsyncFileNonDurable
+	init( NON_DURABLE_MAX_WRITE_DELAY,                         5.0 );
 	init( MAX_PRIOR_MODIFICATION_DELAY,                        1.0 ); if( randomize && BUGGIFY ) MAX_PRIOR_MODIFICATION_DELAY = 10.0;
 
 	//GenericActors

flow/Knobs.h

@@ -149,6 +149,7 @@ public:
 	int DISABLE_POSIX_KERNEL_AIO;
 
 	// AsyncFileNonDurable
+	double NON_DURABLE_MAX_WRITE_DELAY;
 	double MAX_PRIOR_MODIFICATION_DELAY;
 
 	// GenericActors

flow/UnitTest.cpp

@@ -26,3 +26,40 @@ UnitTest::UnitTest(const char* name, const char* file, int line, TestFunction fu
   : name(name), file(file), line(line), func(func), next(g_unittests.tests) {
 	g_unittests.tests = this;
 }
+
+void UnitTestParameters::set(const std::string& name, const std::string& value) {
+	printf("setting %s = %s\n", name.c_str(), value.c_str());
+	params[name] = value;
+}
+
+Optional<std::string> UnitTestParameters::get(const std::string& name) const {
+	auto it = params.find(name);
+	if (it != params.end()) {
+		return it->second;
+	}
+	return {};
+}
+
+void UnitTestParameters::set(const std::string& name, int64_t value) {
+	set(name, format("%" PRId64, value));
+};
+
+void UnitTestParameters::set(const std::string& name, double value) {
+	set(name, format("%g", value));
+};
+
+Optional<int64_t> UnitTestParameters::getInt(const std::string& name) const {
+	auto opt = get(name);
+	if (opt.present()) {
+		return atoll(opt.get().c_str());
+	}
+	return {};
+}
+
+Optional<double> UnitTestParameters::getDouble(const std::string& name) const {
+	auto opt = get(name);
+	if (opt.present()) {
+		return atof(opt.get().c_str());
+	}
+	return {};
+}

flow/UnitTest.h

@@ -45,8 +45,34 @@
 
 #include "flow/flow.h"
 
+#include <cinttypes>
+
+struct UnitTestParameters {
+	// Map of named case-sensitive parameters
+	std::map<std::string, std::string> params;
+
+	// Set a named parameter to a string value, replacing any existing value
+	void set(const std::string& name, const std::string& value);
+
+	// Set a named parameter to an integer converted to a string value, replacing any existing value
+	void set(const std::string& name, int64_t value);
+
+	// Set a named parameter to a double converted to a string value, replacing any existing value
+	void set(const std::string& name, double value);
+
+	// Get a parameter's value, will return !present() if parameter was not set
+	Optional<std::string> get(const std::string& name) const;
+
+	// Get a parameter's value as an integer, will return !present() if parameter was not set
+	Optional<int64_t> getInt(const std::string& name) const;
+
+	// Get a parameter's value parsed as a double, will return !present() if parameter was not set
+	Optional<double> getDouble(const std::string& name) const;
+};
+
+// Unit test definition structured as a linked list item
 struct UnitTest {
-	typedef Future<Void> (*TestFunction)();
+	typedef Future<Void> (*TestFunction)(const UnitTestParameters& params);
 
 	const char* name;
 	const char* file;
@@ -57,6 +83,7 @@ struct UnitTest {
 	UnitTest(const char* name, const char* file, int line, TestFunction func);
 };
 
+// Collection of unit tests in the form of a linked list
 struct UnitTestCollection {
 	UnitTest* tests;
 };
@@ -71,17 +98,17 @@ extern UnitTestCollection g_unittests;
 
 #ifdef FLOW_DISABLE_UNIT_TESTS
 
-#define TEST_CASE(name) static Future<Void> FILE_UNIQUE_NAME(disabled_testcase_func)()
+#define TEST_CASE(name) static Future<Void> FILE_UNIQUE_NAME(disabled_testcase_func)(const UnitTestParameters& params)
 #define ACTOR_TEST_CASE(actorname, name)
 
 #else
 
 #define TEST_CASE(name)                                                                                                \
-	static Future<Void> FILE_UNIQUE_NAME(testcase_func)();                                                             \
+	static Future<Void> FILE_UNIQUE_NAME(testcase_func)(const UnitTestParameters& params);                             \
 	namespace {                                                                                                        \
 	static UnitTest FILE_UNIQUE_NAME(testcase)(name, __FILE__, __LINE__, &FILE_UNIQUE_NAME(testcase_func));            \
 	}                                                                                                                  \
-	static Future<Void> FILE_UNIQUE_NAME(testcase_func)()
+	static Future<Void> FILE_UNIQUE_NAME(testcase_func)(const UnitTestParameters& params)
 
 // ACTOR_TEST_CASE generated by actorcompiler; don't use directly
 #define ACTOR_TEST_CASE(actorname, name)                                                                               \

flow/actorcompiler/ActorParser.cs

@@ -535,7 +535,13 @@ namespace actorcompiler
             actor.testCaseParameters = str(paramRange);
 
             actor.name = "flowTestCase" + toks.First().SourceLine;
-            actor.parameters = new VarDeclaration[] { };
+            actor.parameters = new VarDeclaration[] { new VarDeclaration {
+                    name = "params",
+                    type = "UnitTestParameters",
+                    initializer = "",
+                    initializerConstructorSyntax = false
+                }
+            };
             actor.returnType = "Void";
         }
 

flow/network.h

@@ -482,7 +482,8 @@ public:
 		enBlobCredentialFiles = 10,
 		enNetworkAddressesFunc = 11,
 		enClientFailureMonitor = 12,
-		enSQLiteInjectedError = 13
+		enSQLiteInjectedError = 13,
+		enGlobalConfig = 14
 	};
 
 	virtual void longTaskCheck(const char* name) {}

tests/RedwoodCorrectness.txt

@@ -4,4 +4,4 @@ useDB=false
 
     testName=UnitTests
     maxTestCases=0
-    testsMatching=!/redwood/correctness/
+    testsMatching=/redwood/correctness/

tests/RedwoodCorrectnessBTree.txt

@@ -4,4 +4,4 @@ useDB=false
 
     testName=UnitTests
     maxTestCases=0
-    testsMatching=!/redwood/correctness/btree
+    testsMatching=/redwood/correctness/btree

tests/RedwoodCorrectnessPager.txt

@@ -4,4 +4,4 @@ useDB=false
 
     testName=UnitTests
     maxTestCases=0
-    testsMatching=!/redwood/correctness/pager
+    testsMatching=:/redwood/correctness/pager

tests/RedwoodCorrectnessUnits.txt

@@ -4,4 +4,4 @@ useDB=false
 
     testName=UnitTests
     maxTestCases=0
-    testsMatching=!/redwood/correctness/unit/
+    testsMatching=/redwood/correctness/unit/

tests/RedwoodPerfPrefixCompression.txt

@@ -4,4 +4,4 @@ useDB=false
 
     testName=UnitTests
     maxTestCases=0
-    testsMatching=!/redwood/performance/prefixSizeComparison
+    testsMatching=:/redwood/performance/prefixSizeComparison

tests/RedwoodPerfSequentialInsert.txt

@@ -4,4 +4,4 @@ useDB=false
 
     testName=UnitTests
     maxTestCases=0
-    testsMatching=!/redwood/performance/sequentialInsert
+    testsMatching=:/redwood/performance/sequentialInsert

tests/RedwoodPerfSet.txt

@@ -4,4 +4,4 @@ useDB=false
 
     testName=UnitTests
     maxTestCases=0
-    testsMatching=!/redwood/performance/set
+    testsMatching=:/redwood/performance/set

tests/RedwoodPerfTests.txt

@@ -4,4 +4,4 @@ useDB=false
 
     testName=UnitTests
     maxTestCases=0
-    testsMatching=!/redwood/performance/
+    testsMatching=:/redwood/performance/

tests/TestRunner/TestRunner.py

@@ -264,6 +264,40 @@ def process_traces(basedir, testname, path, out, aggregationPolicy, symbolicateB
     parser.writeObject({'CMakeSEED': str(cmake_seed)})
     return res
 
+class RestartTestPolicy:
+    def __init__(self, name, old_binary, new_binary):
+        # Default is to use the same binary for the restart test, unless constraints are satisfied.
+        self._first_binary = new_binary
+        self._second_binary = new_binary
+        if old_binary is None:
+            _logger.info("No old binary provided")
+        old_binary_version_raw = subprocess.check_output([old_binary, '--version']).decode('utf-8')
+        match = re.match('FoundationDB.*\(v([0-9]+\.[0-9]+\.[0-9]+)\)', old_binary_version_raw)
+        assert match, old_binary_version_raw
+        old_binary_version = tuple(map(int, match.group(1).split('.')))
+        match = re.match('.*/restarting/from_([0-9]+\.[0-9]+\.[0-9]+)/', name)
+        if match: # upgrading _from_
+            lower_bound = tuple(map(int, match.group(1).split('.')))
+            if old_binary_version >= lower_bound:
+                self._first_binary = old_binary
+                _logger.info("Using old binary as first binary: {} >= {}".format(old_binary_version, lower_bound))
+            else:
+                _logger.info("Using new binary as first binary: {} < {}".format(old_binary_version, lower_bound))
+        match = re.match('.*/restarting/to_([0-9]+\.[0-9]+\.[0-9]+)/', name)
+        if match: # downgrading _to_
+            lower_bound = tuple(map(int, match.group(1).split('.')))
+            if old_binary_version >= lower_bound:
+                self._second_binary = old_binary
+                _logger.info("Using old binary as second binary: {} >= {}".format(old_binary_version, lower_bound))
+            else:
+                _logger.info("Using new binary as second binary: {} < {}".format(old_binary_version, lower_bound))
+
+    def first_binary(self):
+        return self._first_binary
+
+    def second_binary(self):
+        return self._second_binary
+
 def run_simulation_test(basedir, options):
     fdbserver = os.path.join(basedir, 'bin', 'fdbserver')
     pargs = [fdbserver,
@@ -298,14 +332,19 @@ def run_simulation_test(basedir, options):
     os.mkdir(wd)
     return_codes = {} # {command: return_code}
     first = True
+    restart_test_policy = None
+    if len(options.testfile) > 1:
+        restart_test_policy = RestartTestPolicy(options.testfile[0], options.old_binary, fdbserver)
     for testfile in options.testfile:
         tmp = list(pargs)
-        # old_binary is not under test, so don't run under valgrind
         valgrind_args = []
-        if first and options.old_binary is not None and len(options.testfile) > 1:
-            _logger.info("Run old binary at {}".format(options.old_binary))
-            tmp[0] = options.old_binary
-        elif options.use_valgrind:
+        if restart_test_policy is not None:
+            if first:
+                tmp[0] = restart_test_policy.first_binary()
+            else:
+                tmp[0] = restart_test_policy.second_binary()
+        # old_binary is not under test, so don't run under valgrind
+        if options.use_valgrind and tmp[0] == fdbserver:
             valgrind_args = ['valgrind', '--error-exitcode=99', '--']
         if not first:
             tmp.append('-R')

tests/rare/RedwoodCorrectnessBTree.toml

@@ -6,4 +6,4 @@ startDelay = 0
     [[test.workload]]
     testName = 'UnitTests'
     maxTestCases = 0
-    testsMatching = '!/redwood/correctness/btree'
+    testsMatching = '/redwood/correctness/btree'

tests/restarting/to_6.3.10/CycleTestRestart-1.txt

@@ -1,4 +1,5 @@
-storageEngineExcludeType=-1
+storageEngineExcludeTypes=-1,-2
+maxTLogVersion=6
 testTitle=Clogged
     clearAfterTest=false
     testName=Cycle

tests/restarting/to_6.3.10/CycleTestRestart-2.txt

@@ -1,4 +1,5 @@
-storageEngineExcludeType=-1
+storageEngineExcludeTypes=-1,-2
+maxTLogVersion=6
 testTitle=Clogged
     runSetup=false
     testName=Cycle