foundationdb/fdbclient/ManagementAPI.actor.cpp

/*
 * ManagementAPI.actor.cpp
 *
 * This source file is part of the FoundationDB open source project
 *
 * Copyright 2013-2018 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 <cinttypes>

#include "fdbclient/ManagementAPI.actor.h"

#include "fdbclient/SystemData.h"
#include "fdbclient/NativeAPI.actor.h"
#include "fdbclient/CoordinationInterface.h"
#include "fdbclient/DatabaseContext.h"
#include "fdbrpc/simulator.h"
#include "fdbclient/StatusClient.h"
#include "flow/UnitTest.h"
#include "fdbrpc/ReplicationPolicy.h"
#include "fdbrpc/Replication.h"
#include "flow/actorcompiler.h"  // This must be the last #include.

ACTOR static Future<vector<AddressExclusion>> getExcludedServers(Transaction* tr);

bool isInteger(const std::string& s) {
	if( s.empty() ) return false;
	char *p;
	strtol(s.c_str(), &p, 10);
	return (*p == 0);
}

// Defines the mapping between configuration names (as exposed by fdbcli, buildConfiguration()) and actual configuration parameters
std::map<std::string, std::string> configForToken( std::string const& mode ) {
	std::map<std::string, std::string> out;
	std::string p = configKeysPrefix.toString();

	if (mode == "new") {
		out[p+"initialized"]="1";
		return out;
	}

	size_t pos;

	// key:=value is unvalidated and unchecked
	pos = mode.find( ":=" );
	if( pos != std::string::npos ) {
		out[p+mode.substr(0, pos)] = mode.substr(pos+2);
		return out;
	}

	// key=value is constrained to a limited set of options and basic validation is performed
	pos = mode.find( "=" );
	if( pos != std::string::npos ) {
		std::string key = mode.substr(0, pos);
		std::string value = mode.substr(pos+1);

		if( (key == "logs" || key == "proxies" || key == "resolvers" || key == "remote_logs" || key == "log_routers" || key == "satellite_logs" || key == "usable_regions" || key == "repopulate_anti_quorum") && isInteger(value) ) {
			out[p+key] = value;
		}

		if( key == "regions" ) {
			json_spirit::mValue mv;
			json_spirit::read_string( value, mv );

			StatusObject regionObj;
			regionObj["regions"] = mv;
			out[p+key] = BinaryWriter::toValue(regionObj, IncludeVersion()).toString();
		}

		return out;
	}

	Optional<KeyValueStoreType> logType;
	Optional<KeyValueStoreType> storeType;
	if (mode == "ssd-1") {
		logType = KeyValueStoreType::SSD_BTREE_V1;
		storeType = KeyValueStoreType::SSD_BTREE_V1;
	} else if (mode == "ssd" || mode == "ssd-2") {
		logType = KeyValueStoreType::SSD_BTREE_V2;
		storeType = KeyValueStoreType::SSD_BTREE_V2;
	} else if (mode == "ssd-redwood-experimental") {
		logType = KeyValueStoreType::SSD_BTREE_V2;
		storeType = KeyValueStoreType::SSD_REDWOOD_V1;
	} else if (mode == "memory" || mode == "memory-2") {
		logType = KeyValueStoreType::SSD_BTREE_V2;
		storeType= KeyValueStoreType::MEMORY;
	} else if (mode == "memory-1") {
		logType = KeyValueStoreType::MEMORY;
		storeType= KeyValueStoreType::MEMORY;
	}
	// Add any new store types to fdbserver/workloads/ConfigureDatabase, too

	if (storeType.present()) {
		out[p+"log_engine"] = format("%d", logType.get());
		out[p+"storage_engine"] = format("%d", storeType.get());
		return out;
	}

	std::string redundancy, log_replicas;
	Reference<IReplicationPolicy> storagePolicy;
	Reference<IReplicationPolicy> tLogPolicy;

	bool redundancySpecified = true;
	if (mode == "single") {
		redundancy="1";
		log_replicas="1";
		storagePolicy = tLogPolicy = Reference<IReplicationPolicy>(new PolicyOne());

	} else if(mode == "double" || mode == "fast_recovery_double") {
		redundancy="2";
		log_replicas="2";
		storagePolicy = tLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(2, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())));
	} else if(mode == "triple" || mode == "fast_recovery_triple") {
		redundancy="3";
		log_replicas="3";
		storagePolicy = tLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(3, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())));
	} else if(mode == "three_datacenter" || mode == "multi_dc") {
		redundancy="6";
		log_replicas="4";
		storagePolicy = Reference<IReplicationPolicy>(new PolicyAcross(3, "dcid",
			Reference<IReplicationPolicy>(new PolicyAcross(2, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())))
		));
		tLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(2, "dcid",
			Reference<IReplicationPolicy>(new PolicyAcross(2, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())))
		));
	} else if(mode == "three_datacenter_fallback") {
		redundancy="4";
		log_replicas="4";
		storagePolicy = tLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(2, "dcid", Reference<IReplicationPolicy>(new PolicyAcross(2, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())))));
	} else if(mode == "three_data_hall") {
		redundancy="3";
		log_replicas="4";
		storagePolicy = Reference<IReplicationPolicy>(new PolicyAcross(3, "data_hall", Reference<IReplicationPolicy>(new PolicyOne())));
		tLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(2, "data_hall",
			Reference<IReplicationPolicy>(new PolicyAcross(2, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())))
		));
	} else if(mode == "three_data_hall_fallback") {
		redundancy="2";
		log_replicas="4";
		storagePolicy = Reference<IReplicationPolicy>(new PolicyAcross(2, "data_hall", Reference<IReplicationPolicy>(new PolicyOne())));
		tLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(2, "data_hall",
			Reference<IReplicationPolicy>(new PolicyAcross(2, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())))
		));
	} else
		redundancySpecified = false;
	if (redundancySpecified) {
		out[p+"storage_replicas"] = redundancy;
		out[p+"log_replicas"] = log_replicas;
		out[p+"log_anti_quorum"] = "0";

		BinaryWriter policyWriter(IncludeVersion());
		serializeReplicationPolicy(policyWriter, storagePolicy);
		out[p+"storage_replication_policy"] = policyWriter.toValue().toString();

		policyWriter = BinaryWriter(IncludeVersion());
		serializeReplicationPolicy(policyWriter, tLogPolicy);
		out[p+"log_replication_policy"] = policyWriter.toValue().toString();
		return out;
	}

	std::string remote_redundancy, remote_log_replicas;
	Reference<IReplicationPolicy> remoteTLogPolicy;
	bool remoteRedundancySpecified = true;
	if (mode == "remote_default") {
		remote_redundancy="0";
		remote_log_replicas="0";
		remoteTLogPolicy = Reference<IReplicationPolicy>();
	} else if (mode == "remote_single") {
		remote_redundancy="1";
		remote_log_replicas="1";
		remoteTLogPolicy = Reference<IReplicationPolicy>(new PolicyOne());
	} else if(mode == "remote_double") {
		remote_redundancy="2";
		remote_log_replicas="2";
		remoteTLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(2, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())));
	} else if(mode == "remote_triple") {
		remote_redundancy="3";
		remote_log_replicas="3";
		remoteTLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(3, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())));
	} else if(mode == "remote_three_data_hall") { //FIXME: not tested in simulation
		remote_redundancy="3";
		remote_log_replicas="4";
		remoteTLogPolicy = Reference<IReplicationPolicy>(new PolicyAcross(2, "data_hall",
			Reference<IReplicationPolicy>(new PolicyAcross(2, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())))
		));
	} else
		remoteRedundancySpecified = false;
	if (remoteRedundancySpecified) {
		out[p+"remote_log_replicas"] = remote_log_replicas;

		BinaryWriter policyWriter(IncludeVersion());
		serializeReplicationPolicy(policyWriter, remoteTLogPolicy);
		out[p+"remote_log_policy"] = policyWriter.toValue().toString();
		return out;
	}

	return out;
}

ConfigurationResult::Type buildConfiguration( std::vector<StringRef> const& modeTokens, std::map<std::string, std::string>& outConf ) {
	for(auto it : modeTokens) {
		std::string mode = it.toString();
		auto m = configForToken( mode );
		if( !m.size() ) {
			TraceEvent(SevWarnAlways, "UnknownOption").detail("Option", mode);
			return ConfigurationResult::UNKNOWN_OPTION;
		}

		for( auto t = m.begin(); t != m.end(); ++t ) {
			if( outConf.count( t->first ) ) {
				TraceEvent(SevWarnAlways, "ConflictingOption").detail("Option", t->first);
				return ConfigurationResult::CONFLICTING_OPTIONS;
			}
			outConf[t->first] = t->second;
		}
	}
	auto p = configKeysPrefix.toString();
	if(!outConf.count(p + "storage_replication_policy") && outConf.count(p + "storage_replicas")) {
		int storageCount = stoi(outConf[p + "storage_replicas"]);
		Reference<IReplicationPolicy> storagePolicy = Reference<IReplicationPolicy>(new PolicyAcross(storageCount, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())));
		BinaryWriter policyWriter(IncludeVersion());
		serializeReplicationPolicy(policyWriter, storagePolicy);
		outConf[p+"storage_replication_policy"] = policyWriter.toValue().toString();
	}

	if(!outConf.count(p + "log_replication_policy") && outConf.count(p + "log_replicas")) {
		int logCount = stoi(outConf[p + "log_replicas"]);
		Reference<IReplicationPolicy> logPolicy = Reference<IReplicationPolicy>(new PolicyAcross(logCount, "zoneid", Reference<IReplicationPolicy>(new PolicyOne())));
		BinaryWriter policyWriter(IncludeVersion());
		serializeReplicationPolicy(policyWriter, logPolicy);
		outConf[p+"log_replication_policy"] = policyWriter.toValue().toString();
	}
	return ConfigurationResult::SUCCESS;
}

ConfigurationResult::Type buildConfiguration( std::string const& configMode, std::map<std::string, std::string>& outConf ) {
	std::vector<StringRef> modes;

	int p = 0;
	while ( p < configMode.size() ) {
		int end = configMode.find_first_of(' ', p);
		if (end == configMode.npos) end = configMode.size();
		modes.push_back( StringRef(configMode).substr(p, end-p) );
		p = end+1;
	}

	return buildConfiguration( modes, outConf );
}

bool isCompleteConfiguration( std::map<std::string, std::string> const& options ) {
	std::string p = configKeysPrefix.toString();

	return 	options.count( p+"log_replicas" ) == 1 &&
			options.count( p+"log_anti_quorum" ) == 1 &&
			options.count( p+"storage_replicas" ) == 1 &&
			options.count( p+"log_engine" ) == 1 &&
			options.count( p+"storage_engine" ) == 1;
}

ACTOR Future<DatabaseConfiguration> getDatabaseConfiguration( Database cx ) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption(FDBTransactionOptions::LOCK_AWARE);
			Standalone<RangeResultRef> res = wait( tr.getRange(configKeys, CLIENT_KNOBS->TOO_MANY) );
			ASSERT( res.size() < CLIENT_KNOBS->TOO_MANY );
			DatabaseConfiguration config;
			config.fromKeyValues((VectorRef<KeyValueRef>) res);
			return config;
		} catch( Error &e ) {
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<ConfigurationResult::Type> changeConfig( Database cx, std::map<std::string, std::string> m, bool force ) {
	state StringRef initIdKey = LiteralStringRef( "\xff/init_id" );
	state Transaction tr(cx);

	if (!m.size()) {
		return ConfigurationResult::NO_OPTIONS_PROVIDED;
	}

	// make sure we have essential configuration options
	std::string initKey = configKeysPrefix.toString() + "initialized";
	state bool creating = m.count( initKey ) != 0;
	if (creating) {
		m[initIdKey.toString()] = deterministicRandom()->randomUniqueID().toString();
		if (!isCompleteConfiguration(m)) {
			return ConfigurationResult::INCOMPLETE_CONFIGURATION;
		}
	}

	state Future<Void> tooLong = delay(60);
	state Key versionKey = BinaryWriter::toValue(deterministicRandom()->randomUniqueID(),Unversioned());
	state bool oldReplicationUsesDcId = false;
	loop {
		try {
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			tr.setOption( FDBTransactionOptions::USE_PROVISIONAL_PROXIES );

			if(!creating && !force) {
				state Future<Standalone<RangeResultRef>> fConfig = tr.getRange(configKeys, CLIENT_KNOBS->TOO_MANY);
				state Future<vector<ProcessData>> fWorkers = getWorkers(&tr);
				wait( success(fConfig) || tooLong );

				if(!fConfig.isReady()) {
					return ConfigurationResult::DATABASE_UNAVAILABLE;
				}

				if(fConfig.isReady()) {
					ASSERT( fConfig.get().size() < CLIENT_KNOBS->TOO_MANY );
					state DatabaseConfiguration oldConfig;
					oldConfig.fromKeyValues((VectorRef<KeyValueRef>) fConfig.get());
					state DatabaseConfiguration newConfig = oldConfig;
					for(auto kv : m) {
						newConfig.set(kv.first, kv.second);
					}
					if(!newConfig.isValid()) {
						return ConfigurationResult::INVALID_CONFIGURATION;
					}

					if(newConfig.tLogPolicy->attributeKeys().count("dcid") && newConfig.regions.size()>0) {
						return ConfigurationResult::REGION_REPLICATION_MISMATCH;
					}

					oldReplicationUsesDcId = oldReplicationUsesDcId || oldConfig.tLogPolicy->attributeKeys().count("dcid");

					if(oldConfig.usableRegions != newConfig.usableRegions) {
						//cannot change region configuration
						std::map<Key,int32_t> dcId_priority;
						for(auto& it : newConfig.regions) {
							dcId_priority[it.dcId] = it.priority;
						}
						for(auto& it : oldConfig.regions) {
							if(!dcId_priority.count(it.dcId) || dcId_priority[it.dcId] != it.priority) {
								return ConfigurationResult::REGIONS_CHANGED;
							}
						}

						//must only have one region with priority >= 0
						int activeRegionCount = 0;
						for(auto& it : newConfig.regions) {
							if(it.priority >= 0) {
								activeRegionCount++;
							}
						}
						if(activeRegionCount > 1) {
							return ConfigurationResult::MULTIPLE_ACTIVE_REGIONS;
						}
					}

					state Future<Standalone<RangeResultRef>> fServerList = (newConfig.regions.size()) ? tr.getRange( serverListKeys, CLIENT_KNOBS->TOO_MANY ) : Future<Standalone<RangeResultRef>>();

					if(newConfig.usableRegions==2) {
						if(oldReplicationUsesDcId) {
								state Future<Standalone<RangeResultRef>> fLocalityList = tr.getRange( tagLocalityListKeys, CLIENT_KNOBS->TOO_MANY );
								wait( success(fLocalityList) || tooLong );
								if(!fLocalityList.isReady()) {
									return ConfigurationResult::DATABASE_UNAVAILABLE;
								}
								Standalone<RangeResultRef> localityList = fLocalityList.get();
								ASSERT( !localityList.more && localityList.size() < CLIENT_KNOBS->TOO_MANY );

								std::set<Key> localityDcIds;
								for(auto& s : localityList) {
									auto dc = decodeTagLocalityListKey( s.key );
									if(dc.present()) {
										localityDcIds.insert(dc.get());
									}
								}

								for(auto& it : newConfig.regions) {
									if(localityDcIds.count(it.dcId) == 0) {
										return ConfigurationResult::DCID_MISSING;
									}
								}
						} else {
							//all regions with priority >= 0 must be fully replicated
							state std::vector<Future<Optional<Value>>> replicasFutures;
							for(auto& it : newConfig.regions) {
								if(it.priority >= 0) {
									replicasFutures.push_back(tr.get(datacenterReplicasKeyFor(it.dcId)));
								}
							}
							wait( waitForAll(replicasFutures) || tooLong );

							for(auto& it : replicasFutures) {
								if(!it.isReady()) {
									return ConfigurationResult::DATABASE_UNAVAILABLE;
								}
								if(!it.get().present()) {
									return ConfigurationResult::REGION_NOT_FULLY_REPLICATED;
								}
							}
						}
					}

					if(newConfig.regions.size()) {
						//all storage servers must be in one of the regions
						wait( success(fServerList) || tooLong );
						if(!fServerList.isReady()) {
							return ConfigurationResult::DATABASE_UNAVAILABLE;
						}
						Standalone<RangeResultRef> serverList = fServerList.get();
						ASSERT( !serverList.more && serverList.size() < CLIENT_KNOBS->TOO_MANY );

						std::set<Key> newDcIds;
						for(auto& it : newConfig.regions) {
							newDcIds.insert(it.dcId);
						}
						std::set<Key> missingDcIds;
						for(auto& s : serverList) {
							auto ssi = decodeServerListValue( s.value );
							if ( !ssi.locality.dcId().present() || !newDcIds.count(ssi.locality.dcId().get()) ) {
								missingDcIds.insert(ssi.locality.dcId().get());
							}
						}
						if(missingDcIds.size() > (oldReplicationUsesDcId ? 1 : 0)) {
							return ConfigurationResult::STORAGE_IN_UNKNOWN_DCID;
						}
					}

					wait( success(fWorkers) || tooLong );
					if(!fWorkers.isReady()) {
						return ConfigurationResult::DATABASE_UNAVAILABLE;
					}

					if(newConfig.regions.size()) {
						std::map<Optional<Key>, std::set<Optional<Key>>> dcId_zoneIds;
						for(auto& it : fWorkers.get()) {
							if( it.processClass.machineClassFitness(ProcessClass::Storage) <= ProcessClass::WorstFit ) {
								dcId_zoneIds[it.locality.dcId()].insert(it.locality.zoneId());
							}
						}
						for(auto& region : newConfig.regions) {
							if(dcId_zoneIds[region.dcId].size() < std::max(newConfig.storageTeamSize, newConfig.tLogReplicationFactor)) {
								return ConfigurationResult::NOT_ENOUGH_WORKERS;
							}
							if(region.satelliteTLogReplicationFactor > 0 && region.priority >= 0) {
								int totalSatelliteProcesses = 0;
								for(auto& sat : region.satellites) {
									totalSatelliteProcesses += dcId_zoneIds[sat.dcId].size();
								}
								if(totalSatelliteProcesses < region.satelliteTLogReplicationFactor) {
									return ConfigurationResult::NOT_ENOUGH_WORKERS;
								}
							}
						}
					} else {
						std::set<Optional<Key>> zoneIds;
						for(auto& it : fWorkers.get()) {
							if( it.processClass.machineClassFitness(ProcessClass::Storage) <= ProcessClass::WorstFit ) {
								zoneIds.insert(it.locality.zoneId());
							}
						}
						if(zoneIds.size() < std::max(newConfig.storageTeamSize, newConfig.tLogReplicationFactor)) {
							return ConfigurationResult::NOT_ENOUGH_WORKERS;
						}
					}
				}
			}

			if (creating) {
				tr.setOption( FDBTransactionOptions::INITIALIZE_NEW_DATABASE );
				tr.addReadConflictRange( singleKeyRange( initIdKey ) );
			} else if (m.size()) {
				// might be used in an emergency transaction, so make sure it is retry-self-conflicting and CAUSAL_WRITE_RISKY
				tr.setOption( FDBTransactionOptions::CAUSAL_WRITE_RISKY );
				tr.addReadConflictRange( singleKeyRange(m.begin()->first) );
			}

			for(auto i=m.begin(); i!=m.end(); ++i)
				tr.set( StringRef(i->first), StringRef(i->second) );

			tr.addReadConflictRange( singleKeyRange(moveKeysLockOwnerKey) );
			tr.set( moveKeysLockOwnerKey, versionKey );

			wait( tr.commit() );
			break;
		} catch (Error& e) {
			state Error e1(e);
			if ( (e.code() == error_code_not_committed || e.code() == error_code_transaction_too_old ) && creating) {
				// The database now exists.  Determine whether we created it or it was already existing/created by someone else.  The latter is an error.
				tr.reset();
				loop {
					try {
						tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );
						tr.setOption( FDBTransactionOptions::LOCK_AWARE );
						tr.setOption( FDBTransactionOptions::USE_PROVISIONAL_PROXIES );

						Optional<Value> v = wait( tr.get( initIdKey ) );
						if (v != m[initIdKey.toString()])
							return ConfigurationResult::DATABASE_ALREADY_CREATED;
						else
							return ConfigurationResult::DATABASE_CREATED;
					} catch (Error& e2) {
						wait( tr.onError(e2) );
					}
				}
			}
			wait( tr.onError(e1) );
		}
	}
	return ConfigurationResult::SUCCESS;
}

ConfigureAutoResult parseConfig( StatusObject const& status ) {
	ConfigureAutoResult result;
	StatusObjectReader statusObj(status);

	StatusObjectReader statusObjCluster;
	if (!statusObj.get("cluster", statusObjCluster))
		return ConfigureAutoResult();

	StatusObjectReader statusObjConfig;
	if (!statusObjCluster.get("configuration", statusObjConfig))
		return ConfigureAutoResult();

	if (!statusObjConfig.get("redundancy.factor", result.old_replication))
		return ConfigureAutoResult();

	result.auto_replication = result.old_replication;

	int storage_replication;
	int log_replication;
	if( result.old_replication == "single" ) {
		result.auto_replication = "double";
		storage_replication = 2;
		log_replication = 2;
	} else if( result.old_replication == "double" || result.old_replication == "fast_recovery_double" ) {
		storage_replication = 2;
		log_replication = 2;
	} else if( result.old_replication == "triple" || result.old_replication == "fast_recovery_triple" ) {
		storage_replication = 3;
		log_replication = 3;
	} else if( result.old_replication == "three_datacenter" ) {
		storage_replication = 6;
		log_replication = 4;
	} else if( result.old_replication == "three_datacenter_fallback" ) {
		storage_replication = 4;
		log_replication = 4;
	} else if( result.old_replication == "three_data_hall" ) {
		storage_replication = 3;
		log_replication = 4;
	} else if( result.old_replication == "three_data_hall_fallback" ) {
		storage_replication = 2;
		log_replication = 4;
	} else
		return ConfigureAutoResult();

	StatusObjectReader machinesMap;
	if (!statusObjCluster.get("machines", machinesMap))
		return ConfigureAutoResult();

	std::map<std::string, std::string> machineid_dcid;
	std::set<std::string> datacenters;
	int machineCount = 0;
	for (auto mach : machinesMap.obj()) {
		StatusObjectReader machine(mach.second);
		std::string dcId;
		if (machine.get("datacenter_id", dcId)) {
			machineid_dcid[mach.first] = dcId;
			datacenters.insert(dcId);
		}
		machineCount++;
	}

	result.machines = machineCount;

	if(datacenters.size() > 1)
		return ConfigureAutoResult();

	StatusObjectReader processesMap;
	if (!statusObjCluster.get("processes", processesMap))
		return ConfigureAutoResult();

	std::set<std::string> oldMachinesWithTransaction;
	int oldTransactionProcesses = 0;
	std::map<std::string, std::vector<std::pair<NetworkAddress, ProcessClass>>> machine_processes;
	int processCount = 0;
	for (auto proc : processesMap.obj()){
		StatusObjectReader process(proc.second);
		if (!process.has("excluded") || !process.last().get_bool()) {
			std::string addrStr;
			if (!process.get("address", addrStr))
				return ConfigureAutoResult();
			std::string class_source;
			if (!process.get("class_source", class_source))
				return ConfigureAutoResult();
			std::string class_type;
			if (!process.get("class_type", class_type))
				return ConfigureAutoResult();
			std::string machineId;
			if (!process.get("machine_id", machineId))
				return ConfigureAutoResult();

			NetworkAddress addr = NetworkAddress::parse(addrStr);
			ProcessClass processClass(class_type, class_source);

			if(processClass.classType() == ProcessClass::TransactionClass || processClass.classType() == ProcessClass::LogClass) {
				oldMachinesWithTransaction.insert(machineId);
			}

			if(processClass.classType() == ProcessClass::TransactionClass || processClass.classType() == ProcessClass::ProxyClass || processClass.classType() == ProcessClass::ResolutionClass || processClass.classType() == ProcessClass::StatelessClass || processClass.classType() == ProcessClass::LogClass) {
				oldTransactionProcesses++;
			}

			if( processClass.classSource() == ProcessClass::AutoSource ) {
				processClass = ProcessClass(ProcessClass::UnsetClass, ProcessClass::CommandLineSource);
				result.address_class[addr] = processClass;
			}

			if( processClass.classType() != ProcessClass::TesterClass ) {
				machine_processes[machineId].push_back(std::make_pair(addr, processClass));
				processCount++;
			}
		}
	}

	result.processes = processCount;
	result.old_processes_with_transaction = oldTransactionProcesses;
	result.old_machines_with_transaction = oldMachinesWithTransaction.size();

	std::map<std::pair<int, std::string>, std::vector<std::pair<NetworkAddress, ProcessClass>>> count_processes;
	for( auto& it : machine_processes ) {
		count_processes[std::make_pair(it.second.size(), it.first)] = it.second;
	}

	std::set<std::string> machinesWithTransaction;
	std::set<std::string> machinesWithStorage;
	int totalTransactionProcesses = 0;
	int existingProxyCount = 0;
	int existingResolverCount = 0;
	int existingStatelessCount = 0;
	for( auto& it : machine_processes ) {
		for(auto& proc : it.second ) {
			if(proc.second == ProcessClass::TransactionClass || proc.second == ProcessClass::LogClass) {
				totalTransactionProcesses++;
				machinesWithTransaction.insert(it.first);
			}
			if(proc.second == ProcessClass::StatelessClass) {
				existingStatelessCount++;
			}
			if(proc.second == ProcessClass::ProxyClass) {
				existingProxyCount++;
			}
			if(proc.second == ProcessClass::ResolutionClass) {
				existingResolverCount++;
			}
			if(proc.second == ProcessClass::StorageClass) {
				machinesWithStorage.insert(it.first);
			}
			if(proc.second == ProcessClass::UnsetClass && proc.second.classSource() == ProcessClass::DBSource) {
				machinesWithStorage.insert(it.first);
			}
		}
	}

	if( processCount < 10 )
		return ConfigureAutoResult();

	result.desired_resolvers = 1;
	int resolverCount;
	if (!statusObjConfig.get("resolvers", result.old_resolvers)) {
		result.old_resolvers = CLIENT_KNOBS->DEFAULT_AUTO_RESOLVERS;
		statusObjConfig.get("auto_resolvers", result.old_resolvers);
		result.auto_resolvers = result.desired_resolvers;
		resolverCount = result.auto_resolvers;
	} else {
		result.auto_resolvers = result.old_resolvers;
		resolverCount = result.old_resolvers;
	}

	result.desired_proxies = std::min( 12, processCount / 15 );
	int proxyCount;
	if (!statusObjConfig.get("proxies", result.old_proxies)) {
		result.old_proxies = CLIENT_KNOBS->DEFAULT_AUTO_PROXIES;
		statusObjConfig.get("auto_proxies", result.old_proxies);
		result.auto_proxies = result.desired_proxies;
		proxyCount = result.auto_proxies;
	} else {
		result.auto_proxies = result.old_proxies;
		proxyCount = result.old_proxies;
	}

	result.desired_logs = std::min( 12, processCount / 20 );
	result.desired_logs = std::max( result.desired_logs, log_replication + 1 );
	result.desired_logs = std::min<int>( result.desired_logs, machine_processes.size() );
	int logCount;
	if (!statusObjConfig.get("logs", result.old_logs)) {
		result.old_logs = CLIENT_KNOBS->DEFAULT_AUTO_LOGS;
		statusObjConfig.get("auto_logs", result.old_logs);
		result.auto_logs = result.desired_logs;
		logCount = result.auto_logs;
	} else {
		result.auto_logs = result.old_logs;
		logCount = result.old_logs;
	}

	logCount = std::max(logCount, log_replication);

	totalTransactionProcesses += std::min(existingProxyCount, proxyCount);
	totalTransactionProcesses += std::min(existingResolverCount, resolverCount);
	totalTransactionProcesses += existingStatelessCount;

	//if one process on a machine is transaction class, make them all transaction class
	for( auto& it : count_processes ) {
		if( machinesWithTransaction.count(it.first.second) && !machinesWithStorage.count(it.first.second) ) {
			for(auto& proc : it.second ) {
				if(proc.second == ProcessClass::UnsetClass && proc.second.classSource() == ProcessClass::CommandLineSource) {
					result.address_class[proc.first] = ProcessClass(ProcessClass::TransactionClass, ProcessClass::AutoSource);
					totalTransactionProcesses++;
				}
			}
		}
	}

	int desiredTotalTransactionProcesses = logCount + resolverCount + proxyCount;

	//add machines with all transaction class until we have enough processes and enough machines
	for( auto& it : count_processes ) {
		if( machinesWithTransaction.size() >= logCount && totalTransactionProcesses >= desiredTotalTransactionProcesses )
			break;

		if( !machinesWithTransaction.count(it.first.second) && !machinesWithStorage.count(it.first.second) ) {
			for(auto& proc : it.second ) {
				if(proc.second == ProcessClass::UnsetClass && proc.second.classSource() == ProcessClass::CommandLineSource) {
					ASSERT(proc.second != ProcessClass::TransactionClass);
					result.address_class[proc.first] = ProcessClass(ProcessClass::TransactionClass, ProcessClass::AutoSource);
					totalTransactionProcesses++;
					machinesWithTransaction.insert(it.first.second);
				}
			}
		}
	}

	if( machinesWithTransaction.size() < logCount || totalTransactionProcesses < desiredTotalTransactionProcesses )
		return ConfigureAutoResult();

	result.auto_processes_with_transaction = totalTransactionProcesses;
	result.auto_machines_with_transaction = machinesWithTransaction.size();

	if( 3*totalTransactionProcesses > processCount )
		return ConfigureAutoResult();

	return result;
}

ACTOR Future<ConfigurationResult::Type> autoConfig( Database cx, ConfigureAutoResult conf ) {
	state Transaction tr(cx);
	state Key versionKey = BinaryWriter::toValue(deterministicRandom()->randomUniqueID(),Unversioned());

	if(!conf.address_class.size())
		return ConfigurationResult::INCOMPLETE_CONFIGURATION; //FIXME: correct return type

	loop {
		try {
			tr.setOption( FDBTransactionOptions::ACCESS_SYSTEM_KEYS );
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			tr.setOption( FDBTransactionOptions::USE_PROVISIONAL_PROXIES );

			vector<ProcessData> workers = wait( getWorkers(&tr) );
			std::map<NetworkAddress, Optional<Standalone<StringRef>>> address_processId;
			for(auto& w : workers) {
				address_processId[w.address] = w.locality.processId();
			}

			for(auto& it : conf.address_class) {
				if( it.second.classSource() == ProcessClass::CommandLineSource ) {
					tr.clear(processClassKeyFor(address_processId[it.first].get()));
				} else {
					tr.set(processClassKeyFor(address_processId[it.first].get()), processClassValue(it.second));
				}
			}

			if(conf.address_class.size())
				tr.set(processClassChangeKey, deterministicRandom()->randomUniqueID().toString());

			if(conf.auto_logs != conf.old_logs)
				tr.set(configKeysPrefix.toString() + "auto_logs", format("%d", conf.auto_logs));

			if(conf.auto_proxies != conf.old_proxies)
				tr.set(configKeysPrefix.toString() + "auto_proxies", format("%d", conf.auto_proxies));

			if(conf.auto_resolvers != conf.old_resolvers)
				tr.set(configKeysPrefix.toString() + "auto_resolvers", format("%d", conf.auto_resolvers));


			if( conf.auto_replication != conf.old_replication ) {
				std::vector<StringRef> modes;
				modes.push_back(conf.auto_replication);
				std::map<std::string,std::string> m;
				auto r = buildConfiguration( modes, m );
				if (r != ConfigurationResult::SUCCESS)
					return r;

				for(auto& kv : m)
					tr.set(kv.first, kv.second);
			}

			tr.addReadConflictRange( singleKeyRange(moveKeysLockOwnerKey) );
			tr.set( moveKeysLockOwnerKey, versionKey );

			wait( tr.commit() );
			return ConfigurationResult::SUCCESS;
		} catch( Error &e ) {
			wait( tr.onError(e));
		}
	}
}

Future<ConfigurationResult::Type> changeConfig( Database const& cx, std::vector<StringRef> const& modes, Optional<ConfigureAutoResult> const& conf, bool force ) {
	if( modes.size() && modes[0] == LiteralStringRef("auto") && conf.present() ) {
		return autoConfig(cx, conf.get());
	}

	std::map<std::string,std::string> m;
	auto r = buildConfiguration( modes, m );
	if (r != ConfigurationResult::SUCCESS)
		return r;
	return changeConfig(cx, m, force);
}

Future<ConfigurationResult::Type> changeConfig( Database const& cx, std::string const& modes, bool force ) {
	TraceEvent("ChangeConfig").detail("Mode", modes);
	std::map<std::string,std::string> m;
	auto r = buildConfiguration( modes, m );
	if (r != ConfigurationResult::SUCCESS)
		return r;
	return changeConfig(cx, m, force);
}

ACTOR Future<vector<ProcessData>> getWorkers( Transaction* tr ) {
	state Future<Standalone<RangeResultRef>> processClasses = tr->getRange( processClassKeys, CLIENT_KNOBS->TOO_MANY );
	state Future<Standalone<RangeResultRef>> processData = tr->getRange( workerListKeys, CLIENT_KNOBS->TOO_MANY );

	wait( success(processClasses) && success(processData) );
	ASSERT( !processClasses.get().more && processClasses.get().size() < CLIENT_KNOBS->TOO_MANY );
	ASSERT( !processData.get().more && processData.get().size() < CLIENT_KNOBS->TOO_MANY );

	std::map<Optional<Standalone<StringRef>>,ProcessClass> id_class;
	for( int i = 0; i < processClasses.get().size(); i++ ) {
		id_class[decodeProcessClassKey(processClasses.get()[i].key)] = decodeProcessClassValue(processClasses.get()[i].value);
	}

	std::vector<ProcessData> results;

	for( int i = 0; i < processData.get().size(); i++ ) {
		ProcessData data = decodeWorkerListValue(processData.get()[i].value);
		ProcessClass processClass = id_class[data.locality.processId()];

		if(processClass.classSource() == ProcessClass::DBSource || data.processClass.classType() == ProcessClass::UnsetClass)
			data.processClass = processClass;

		if(data.processClass.classType() != ProcessClass::TesterClass)
			results.push_back(data);
	}

	return results;
}

ACTOR Future<vector<ProcessData>> getWorkers( Database cx ) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption( FDBTransactionOptions::READ_SYSTEM_KEYS );
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );  // necessary?
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			vector<ProcessData> workers = wait( getWorkers(&tr) );
			return workers;
		} catch (Error& e) {
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<std::vector<NetworkAddress>> getCoordinators( Database cx ) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			Optional<Value> currentKey = wait( tr.get( coordinatorsKey ) );
			if (!currentKey.present())
				return std::vector<NetworkAddress>();

			return ClusterConnectionString( currentKey.get().toString() ).coordinators();
		} catch (Error& e) {
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<CoordinatorsResult::Type> changeQuorum( Database cx, Reference<IQuorumChange> change ) {
	state Transaction tr(cx);
	state int retries = 0;
	state std::vector<NetworkAddress> desiredCoordinators;
	state int notEnoughMachineResults = 0;

	loop {
		try {
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			tr.setOption( FDBTransactionOptions::USE_PROVISIONAL_PROXIES );
			Optional<Value> currentKey = wait( tr.get( coordinatorsKey ) );

			if (!currentKey.present())
				return CoordinatorsResult::BAD_DATABASE_STATE;  // Someone deleted this key entirely?

			state ClusterConnectionString old( currentKey.get().toString() );
			if ( cx->getConnectionFile() && old.clusterKeyName().toString() != cx->getConnectionFile()->getConnectionString().clusterKeyName() )
				return CoordinatorsResult::BAD_DATABASE_STATE;  // Someone changed the "name" of the database??

			state CoordinatorsResult::Type result = CoordinatorsResult::SUCCESS;
			if(!desiredCoordinators.size()) {
				std::vector<NetworkAddress> _desiredCoordinators = wait( change->getDesiredCoordinators( &tr, old.coordinators(), Reference<ClusterConnectionFile>(new ClusterConnectionFile(old)), result ) );
				desiredCoordinators = _desiredCoordinators;
			}

			if(result == CoordinatorsResult::NOT_ENOUGH_MACHINES && notEnoughMachineResults < 1) {
				//we could get not_enough_machines if we happen to see the database while the cluster controller is updating the worker list, so make sure it happens twice before returning a failure
				notEnoughMachineResults++;
				wait( delay(1.0) );
				tr.reset();
				continue;
			}
			if (result != CoordinatorsResult::SUCCESS)
				return result;
			if (!desiredCoordinators.size())
				return CoordinatorsResult::INVALID_NETWORK_ADDRESSES;
			std::sort(desiredCoordinators.begin(), desiredCoordinators.end());

			std::string newName = change->getDesiredClusterKeyName();
			if (newName.empty()) newName = old.clusterKeyName().toString();

			if ( old.coordinators() == desiredCoordinators && old.clusterKeyName() == newName)
				return retries ? CoordinatorsResult::SUCCESS : CoordinatorsResult::SAME_NETWORK_ADDRESSES;

			state ClusterConnectionString conn( desiredCoordinators, StringRef( newName + ':' + deterministicRandom()->randomAlphaNumeric( 32 ) ) );

			if(g_network->isSimulated()) {
				for(int i = 0; i < (desiredCoordinators.size()/2)+1; i++) {
					auto address = NetworkAddress(desiredCoordinators[i].ip,desiredCoordinators[i].port,true,false);
					g_simulator.protectedAddresses.insert(address);
					TraceEvent("ProtectCoordinator").detail("Address", address).backtrace();
				}
			}

			TraceEvent("AttemptingQuorumChange").detail("FromCS", old.toString()).detail("ToCS", conn.toString());
			TEST(old.clusterKeyName() != conn.clusterKeyName());  // Quorum change with new name
			TEST(old.clusterKeyName() == conn.clusterKeyName()); // Quorum change with unchanged name

			vector<Future<Optional<LeaderInfo>>> leaderServers;
			ClientCoordinators coord( Reference<ClusterConnectionFile>( new ClusterConnectionFile( conn ) ) );
			for( int i = 0; i < coord.clientLeaderServers.size(); i++ )
				leaderServers.push_back( retryBrokenPromise( coord.clientLeaderServers[i].getLeader, GetLeaderRequest( coord.clusterKey, UID() ), TaskPriority::CoordinationReply ) );

			choose {
				when( wait( waitForAll( leaderServers ) ) ) {}
				when( wait( delay(5.0) ) ) {
					return CoordinatorsResult::COORDINATOR_UNREACHABLE;
				}
			}

			tr.set( coordinatorsKey, conn.toString() );

			wait( tr.commit() );
			ASSERT( false ); //commit should fail, but the value has changed
		} catch (Error& e) {
			TraceEvent("RetryQuorumChange").error(e).detail("Retries", retries);
			wait( tr.onError(e) );
			++retries;
		}
	}
}

struct SpecifiedQuorumChange : IQuorumChange {
	vector<NetworkAddress> desired;
	explicit SpecifiedQuorumChange( vector<NetworkAddress> const& desired ) : desired(desired) {}
	virtual Future<vector<NetworkAddress>> getDesiredCoordinators( Transaction* tr, vector<NetworkAddress> oldCoordinators, Reference<ClusterConnectionFile>, CoordinatorsResult::Type& ) {
		return desired;
	}
};
Reference<IQuorumChange> specifiedQuorumChange(vector<NetworkAddress> const& addresses) { return Reference<IQuorumChange>(new SpecifiedQuorumChange(addresses)); }

struct NoQuorumChange : IQuorumChange {
	virtual Future<vector<NetworkAddress>> getDesiredCoordinators( Transaction* tr, vector<NetworkAddress> oldCoordinators, Reference<ClusterConnectionFile>, CoordinatorsResult::Type& ) {
		return oldCoordinators;
	}
};
Reference<IQuorumChange> noQuorumChange() { return Reference<IQuorumChange>(new NoQuorumChange); }

struct NameQuorumChange : IQuorumChange {
	std::string newName;
	Reference<IQuorumChange> otherChange;
	explicit NameQuorumChange( std::string const& newName, Reference<IQuorumChange> const& otherChange ) : newName(newName), otherChange(otherChange) {}
	virtual Future<vector<NetworkAddress>> getDesiredCoordinators( Transaction* tr, vector<NetworkAddress> oldCoordinators, Reference<ClusterConnectionFile> cf, CoordinatorsResult::Type& t ) {
		return otherChange->getDesiredCoordinators(tr, oldCoordinators, cf, t);
	}
	virtual std::string getDesiredClusterKeyName() {
		return newName;
	}
};
Reference<IQuorumChange> nameQuorumChange(std::string const& name, Reference<IQuorumChange> const& other) {
	return Reference<IQuorumChange>(new NameQuorumChange( name, other ));
}

struct AutoQuorumChange : IQuorumChange {
	int desired;
	explicit AutoQuorumChange( int desired ) : desired(desired) {}

	virtual Future<vector<NetworkAddress>> getDesiredCoordinators( Transaction* tr, vector<NetworkAddress> oldCoordinators, Reference<ClusterConnectionFile> ccf, CoordinatorsResult::Type& err ) {
		return getDesired( this, tr, oldCoordinators, ccf, &err );
	}

	ACTOR static Future<int> getRedundancy( AutoQuorumChange* self, Transaction* tr ) {
		state Future<Optional<Value>> fStorageReplicas = tr->get( LiteralStringRef("storage_replicas").withPrefix( configKeysPrefix ) );
		state Future<Optional<Value>> fLogReplicas = tr->get( LiteralStringRef("log_replicas").withPrefix( configKeysPrefix ) );
		wait( success( fStorageReplicas ) && success( fLogReplicas ) );
		int redundancy = std::min(
			atoi( fStorageReplicas.get().get().toString().c_str() ),
			atoi( fLogReplicas.get().get().toString().c_str() ) );

		return redundancy;
	}

	ACTOR static Future<bool> isAcceptable( AutoQuorumChange* self, Transaction* tr, vector<NetworkAddress> oldCoordinators, Reference<ClusterConnectionFile> ccf, int desiredCount, std::set<AddressExclusion>* excluded ) {
		// Are there enough coordinators for the redundancy level?
		if (oldCoordinators.size() < desiredCount) return false;
		if (oldCoordinators.size() % 2 != 1) return false;

		// Check availability
		ClientCoordinators coord(ccf);
		vector<Future<Optional<LeaderInfo>>> leaderServers;
		for( int i = 0; i < coord.clientLeaderServers.size(); i++ )
			leaderServers.push_back( retryBrokenPromise( coord.clientLeaderServers[i].getLeader, GetLeaderRequest( coord.clusterKey, UID() ), TaskPriority::CoordinationReply ) );
		Optional<vector<Optional<LeaderInfo>>> results = wait( timeout( getAll(leaderServers), CLIENT_KNOBS->IS_ACCEPTABLE_DELAY ) );
		if (!results.present()) return false;  // Not all responded
		for(auto& r : results.get())
			if (!r.present())
				return false;   // Coordinator doesn't know about this database?

		// Check exclusions
		for(auto& c : oldCoordinators) {
			if (addressExcluded(*excluded, c)) return false;
		}

		// Check locality
		// FIXME: Actual locality!
		std::sort( oldCoordinators.begin(), oldCoordinators.end() );
		for(int i=1; i<oldCoordinators.size(); i++)
			if (oldCoordinators[i-1].ip == oldCoordinators[i].ip)
				return false;  // Multiple coordinators share an IP

		return true; // The status quo seems fine
	}

	ACTOR static Future<vector<NetworkAddress>> getDesired( AutoQuorumChange* self, Transaction* tr, vector<NetworkAddress> oldCoordinators, Reference<ClusterConnectionFile> ccf, CoordinatorsResult::Type* err ) {
		state int desiredCount = self->desired;

		if(desiredCount == -1) {
			int redundancy = wait( getRedundancy( self, tr ) );
			desiredCount = redundancy*2 - 1;
		}

		std::vector<AddressExclusion> excl = wait( getExcludedServers( tr ) );
		state std::set<AddressExclusion> excluded( excl.begin(), excl.end() );

		vector<ProcessData> _workers = wait(getWorkers(tr));
		state vector<ProcessData> workers = _workers;

		std::map<NetworkAddress, LocalityData> addr_locality;
		for(auto w : workers)
			addr_locality[w.address] = w.locality;

		// since we don't have the locality data for oldCoordinators:
		//     check if every old coordinator is in the workers vector and
		//     check if multiple old coordinators map to the same locality data (same machine)
		bool checkAcceptable = true;
		std::set<Optional<Standalone<StringRef>>> checkDuplicates;
		for (auto addr : oldCoordinators) {
			auto findResult = addr_locality.find(addr);
			if (findResult == addr_locality.end() || checkDuplicates.count(findResult->second.zoneId())){
				checkAcceptable = false;
				break;
			}
			checkDuplicates.insert(findResult->second.zoneId());
		}

		if (checkAcceptable){
			bool ok = wait(isAcceptable(self, tr, oldCoordinators, ccf, desiredCount, &excluded));
			if (ok) return oldCoordinators;
		}

		std::vector<NetworkAddress> chosen;
		self->addDesiredWorkers(chosen, workers, desiredCount, excluded);

		if (chosen.size() < desiredCount) {
			if (chosen.size() < oldCoordinators.size()) {
				TraceEvent("NotEnoughMachinesForCoordinators").detail("EligibleWorkers", workers.size()).detail("DesiredCoordinators", desiredCount).detail("CurrentCoordinators", oldCoordinators.size());
				*err = CoordinatorsResult::NOT_ENOUGH_MACHINES;
				return vector<NetworkAddress>();
			}
			desiredCount = std::max(oldCoordinators.size(), (workers.size() - 1) | 1);
			chosen.resize(desiredCount);
		}

		return chosen;
	}

	void addDesiredWorkers(vector<NetworkAddress>& chosen, const vector<ProcessData>& workers, int desiredCount, const std::set<AddressExclusion>& excluded) {
		vector<ProcessData> remainingWorkers(workers);
		deterministicRandom()->randomShuffle(remainingWorkers);

		std::partition(remainingWorkers.begin(), remainingWorkers.end(), [](const ProcessData& data) { return (data.processClass == ProcessClass::CoordinatorClass); });

		std::map<StringRef, int> maxCounts;
		std::map<StringRef, std::map<StringRef, int>> currentCounts;
		std::map<StringRef, int> hardLimits;

		vector<StringRef> fields({
			LiteralStringRef("dcid"),
			LiteralStringRef("data_hall"),
			LiteralStringRef("zoneid"),
			LiteralStringRef("machineid")
		});

		for(auto field = fields.begin(); field != fields.end(); field++) {
			if(field->toString() == "zoneid") {
				hardLimits[*field] = 1;
			}
			else {
				hardLimits[*field] = desiredCount;
			}
		}

		while(chosen.size() < desiredCount) {
			bool found = false;
			for (auto worker = remainingWorkers.begin(); worker != remainingWorkers.end(); worker++) {
				if(addressExcluded(excluded, worker->address)) {
					continue;
				}
				bool valid = true;
				for(auto field = fields.begin(); field != fields.end(); field++) {
					if(maxCounts[*field] == 0) {
						maxCounts[*field] = 1;
					}
					auto value = worker->locality.get(*field).orDefault(LiteralStringRef(""));
					auto currentCount = currentCounts[*field][value];
					if(currentCount >= maxCounts[*field]) {
						valid = false;
						break;
					}
				}
				if(valid) {
					for(auto field = fields.begin(); field != fields.end(); field++) {
						auto value = worker->locality.get(*field).orDefault(LiteralStringRef(""));
						currentCounts[*field][value] += 1;
					}
					chosen.push_back(worker->address);
					remainingWorkers.erase(worker);
					found = true;
					break;
				}
			}
			if(!found) {
				bool canIncrement = false;
				for(auto field = fields.begin(); field != fields.end(); field++) {
					if(maxCounts[*field] < hardLimits[*field]) {
						maxCounts[*field] += 1;
						canIncrement = true;
						break;
					}
				}
				if(!canIncrement) {
					break;
				}
			}
		}
	}
};
Reference<IQuorumChange> autoQuorumChange( int desired ) { return Reference<IQuorumChange>(new AutoQuorumChange(desired)); }

ACTOR Future<Void> excludeServers( Database cx, vector<AddressExclusion> servers ) {
	state Transaction tr(cx);
	state Key versionKey = BinaryWriter::toValue(deterministicRandom()->randomUniqueID(),Unversioned());
	state std::string excludeVersionKey = deterministicRandom()->randomUniqueID().toString();

	loop {
		try {
			tr.setOption( FDBTransactionOptions::ACCESS_SYSTEM_KEYS );
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			tr.setOption( FDBTransactionOptions::USE_PROVISIONAL_PROXIES );

			tr.addReadConflictRange( singleKeyRange(excludedServersVersionKey) ); //To conflict with parallel includeServers
			tr.addReadConflictRange( singleKeyRange(moveKeysLockOwnerKey) );
			tr.set( moveKeysLockOwnerKey, versionKey );
			tr.set( excludedServersVersionKey, excludeVersionKey );
			for(auto& s : servers)
				tr.set( encodeExcludedServersKey(s), StringRef() );

			TraceEvent("ExcludeServersCommit").detail("Servers", describe(servers));

			wait( tr.commit() );
			return Void();
		} catch (Error& e) {
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<Void> includeServers( Database cx, vector<AddressExclusion> servers ) {
	state bool includeAll = false;
	state Transaction tr(cx);
	state Key versionKey = BinaryWriter::toValue(deterministicRandom()->randomUniqueID(),Unversioned());
	state std::string excludeVersionKey = deterministicRandom()->randomUniqueID().toString();

	loop {
		try {
			tr.setOption( FDBTransactionOptions::ACCESS_SYSTEM_KEYS );
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			tr.setOption( FDBTransactionOptions::USE_PROVISIONAL_PROXIES );

			// includeServers might be used in an emergency transaction, so make sure it is retry-self-conflicting and CAUSAL_WRITE_RISKY
			tr.setOption( FDBTransactionOptions::CAUSAL_WRITE_RISKY );
			tr.addReadConflictRange( singleKeyRange(excludedServersVersionKey) );
			tr.addReadConflictRange( singleKeyRange(moveKeysLockOwnerKey) );

			tr.set( moveKeysLockOwnerKey, versionKey );
			tr.set( excludedServersVersionKey, excludeVersionKey );

			for(auto& s : servers ) {
				if (!s.isValid()) {
					tr.clear( excludedServersKeys );
					includeAll = true;
				} else if (s.isWholeMachine()) {
					// Eliminate both any ip-level exclusion (1.2.3.4) and any
					// port-level exclusions (1.2.3.4:5)
					// The range ['IP', 'IP;'] was originally deleted. ';' is
					// char(':' + 1). This does not work, as other for all
					// x between 0 and 9, 'IPx' will also be in this range.
					//
					// This is why we now make two clears: first only of the ip
					// address, the second will delete all ports.
					auto addr = encodeExcludedServersKey(s);
					tr.clear(singleKeyRange(addr));
					tr.clear(KeyRangeRef(addr + ':', addr + char(':' + 1)));
				} else {
					tr.clear( encodeExcludedServersKey(s) );
				}
			}

			TraceEvent("IncludeServersCommit").detail("Servers", describe(servers));

			wait( tr.commit() );
			return Void();
		} catch (Error& e) {
			TraceEvent("IncludeServersError").error(e, true);
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<Void> setClass( Database cx, AddressExclusion server, ProcessClass processClass ) {
	state Transaction tr(cx);

	loop {
		try {
			tr.setOption( FDBTransactionOptions::ACCESS_SYSTEM_KEYS );
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			tr.setOption( FDBTransactionOptions::USE_PROVISIONAL_PROXIES );

			vector<ProcessData> workers = wait( getWorkers(&tr) );

			bool foundChange = false;
			for(int i = 0; i < workers.size(); i++) {
				if( server.excludes(workers[i].address) ) {
					if(processClass.classType() != ProcessClass::InvalidClass)
						tr.set(processClassKeyFor(workers[i].locality.processId().get()), processClassValue(processClass));
					else
						tr.clear(processClassKeyFor(workers[i].locality.processId().get()));
					foundChange = true;
				}
			}

			if(foundChange)
				tr.set(processClassChangeKey, deterministicRandom()->randomUniqueID().toString());

			wait( tr.commit() );
			return Void();
		} catch (Error& e) {
			wait( tr.onError(e) );
		}
	}
}

ACTOR static Future<vector<AddressExclusion>> getExcludedServers( Transaction* tr ) {
	Standalone<RangeResultRef> r = wait( tr->getRange( excludedServersKeys, CLIENT_KNOBS->TOO_MANY ) );
	ASSERT( !r.more && r.size() < CLIENT_KNOBS->TOO_MANY );

	vector<AddressExclusion> exclusions;
	for(auto i = r.begin(); i != r.end(); ++i) {
		auto a = decodeExcludedServersKey( i->key );
		if (a.isValid())
			exclusions.push_back( a );
	}
	return exclusions;
}

ACTOR Future<vector<AddressExclusion>> getExcludedServers( Database cx ) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption( FDBTransactionOptions::READ_SYSTEM_KEYS );
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );  // necessary?
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );
			vector<AddressExclusion> exclusions = wait( getExcludedServers(&tr) );
			return exclusions;
		} catch (Error& e) {
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<Void> checkDataDistributionStatus(Database cx, bool printWarningOnly) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption(FDBTransactionOptions::LOCK_AWARE);
			state Optional<Value> overallSwitch = wait(tr.get(dataDistributionModeKey));
			state int currentMode = -1;
			state Optional<Value> healthyZoneValue = wait(tr.get(healthyZoneKey));
			state Optional<Value> rebalanceDDIgnoreValue = wait(tr.get(rebalanceDDIgnoreKey));
			if (overallSwitch.present()) {
				BinaryReader rd(overallSwitch.get(), Unversioned());
				rd >> currentMode;
				if (currentMode == 0) {
					printf("WARNING: Data distribution is off.\n");
				}
			} else {
				currentMode = 1;
			}
			if (currentMode == 1 && !printWarningOnly) {
				printf("Data distribution is on.\n");
			}
			if (healthyZoneValue.present() && decodeHealthyZoneValue(healthyZoneValue.get()).first == ignoreSSFailure) {
				if (currentMode == 1) {
					printf("WARNING: Data distribution is currently turned on but disabled for all storage server "
					       "failures.\n");
				}
			}
			if (rebalanceDDIgnoreValue.present()) {
				if (currentMode == 1) {
					printf("WARNING: Data distribution is currently turned on but MoutainChopper and ValleyFiller are "
					       "currently disabled.\n");
				}
			}
			return Void();
		} catch (Error& e) {
			wait(tr.onError(e));
		}
	}
}

ACTOR Future<Void> printHealthyZone( Database cx ) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption(FDBTransactionOptions::LOCK_AWARE);
			Optional<Value> val = wait( tr.get(healthyZoneKey) );
			if(!val.present() || decodeHealthyZoneValue(val.get()).second <= tr.getReadVersion().get()) {
				printf("No ongoing maintenance.\n");
			} else if (val.present() && decodeHealthyZoneValue(val.get()).first == ignoreSSFailure) {
				printf("Data distribution has been disabled for all storage server failures in this cluster. No "
				       "ongoing maintenance.\n");
			} else {
				auto healthyZone = decodeHealthyZoneValue(val.get());
				printf("Maintenance for zone %s will continue for %" PRId64 " seconds.\n", healthyZone.first.toString().c_str(), (healthyZone.second-tr.getReadVersion().get())/CLIENT_KNOBS->CORE_VERSIONSPERSECOND);
			}
			return Void();
		} catch( Error &e ) {
			wait(tr.onError(e));
		}
	}
}

ACTOR Future<Void> clearHealthyZone(Database cx, bool calledFromCli) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption(FDBTransactionOptions::LOCK_AWARE);
			Optional<Value> val = wait(tr.get(healthyZoneKey));
			if (val.present() && decodeHealthyZoneValue(val.get()).first == ignoreSSFailure) {
				if (calledFromCli) {
					printf("Data distribution has been disabled for all storage server failures in this cluster and "
					       "thus you cannot use this command until you turn on DD by running 'datadistribution on'\n");
				}
				return Void();
			}

			tr.clear(healthyZoneKey);
			wait(tr.commit());
			return Void();
		} catch( Error &e ) {
			wait(tr.onError(e));
		}
	}
}

ACTOR Future<Void> setHealthyZone( Database cx, StringRef zoneId, double seconds ) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption(FDBTransactionOptions::LOCK_AWARE);
			Optional<Value> val = wait(tr.get(healthyZoneKey));
			if (val.present() && decodeHealthyZoneValue(val.get()).first == ignoreSSFailure) {
				printf("Data distribution has been disabled for all storage server failures in this cluster and thus "
				       "you cannot use this command until you turn on DD by running 'datadistribution on'\n");
				return Void();
			}
			Version readVersion = wait(tr.getReadVersion());
			tr.set(healthyZoneKey, healthyZoneValue(zoneId, readVersion + (seconds*CLIENT_KNOBS->CORE_VERSIONSPERSECOND)));
			wait(tr.commit());
			return Void();
		} catch( Error &e ) {
			wait(tr.onError(e));
		}
	}
}

ACTOR Future<Void> setDDIgnoreRebalanceSwitch(Database cx, bool ignoreRebalance) {
	state Transaction tr(cx);
	loop {
		try {
			tr.setOption(FDBTransactionOptions::LOCK_AWARE);
			Optional<Value> val = wait(tr.get(rebalanceDDIgnoreKey));
			if (ignoreRebalance) {
				tr.set(rebalanceDDIgnoreKey, LiteralStringRef("on"));
			} else {
				tr.clear(rebalanceDDIgnoreKey);
			}
			wait(tr.commit());
			return Void();
		} catch (Error& e) {
			wait(tr.onError(e));
		}
	}
}

ACTOR Future<int> setDDMode( Database cx, int mode ) {
	state Transaction tr(cx);
	state int oldMode = -1;
	state BinaryWriter wr(Unversioned());
	wr << mode;

	loop {
		try {
			Optional<Value> old = wait( tr.get( dataDistributionModeKey ) );
			if (oldMode < 0) {
				oldMode = 1;
				if (old.present()) {
					BinaryReader rd(old.get(), Unversioned());
					rd >> oldMode;
				}
			}
			BinaryWriter wrMyOwner(Unversioned());
			wrMyOwner << dataDistributionModeLock;
			tr.set( moveKeysLockOwnerKey, wrMyOwner.toValue() );
			BinaryWriter wrLastWrite(Unversioned());
			wrLastWrite << deterministicRandom()->randomUniqueID();
			tr.set( moveKeysLockWriteKey, wrLastWrite.toValue() );

			tr.set( dataDistributionModeKey, wr.toValue() );
			if (mode) {
				// set DDMode to 1 will enable all disabled parts, for instance the SS failure monitors.
				tr.clear(healthyZoneKey);
				tr.clear(rebalanceDDIgnoreKey);
			}
			wait( tr.commit() );
			return oldMode;
		} catch (Error& e) {
			TraceEvent("SetDDModeRetrying").error(e);
			wait (tr.onError(e));
		}
	}
}

ACTOR Future<std::set<NetworkAddress>> checkForExcludingServers(Database cx, vector<AddressExclusion> excl,
                                                                bool waitForAllExcluded) {
	state std::set<AddressExclusion> exclusions( excl.begin(), excl.end() );
	state std::set<NetworkAddress> inProgressExclusion;

	if (!excl.size()) return inProgressExclusion;

	loop {
		state Transaction tr(cx);

		try {
			tr.setOption( FDBTransactionOptions::READ_SYSTEM_KEYS );
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );  // necessary?
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );

			// Just getting a consistent read version proves that a set of tlogs satisfying the exclusions has completed recovery

			// Check that there aren't any storage servers with addresses violating the exclusions
			Standalone<RangeResultRef> serverList = wait( tr.getRange( serverListKeys, CLIENT_KNOBS->TOO_MANY ) );
			ASSERT( !serverList.more && serverList.size() < CLIENT_KNOBS->TOO_MANY );

			state bool ok = true;
			inProgressExclusion.clear();
			for(auto& s : serverList) {
				auto addr = decodeServerListValue( s.value ).address();
				if ( addressExcluded(exclusions, addr) ) {
					ok = false;
					inProgressExclusion.insert(addr);
				}
			}

			if (ok) {
				Optional<Standalone<StringRef>> value = wait( tr.get(logsKey) );
				ASSERT(value.present());
				auto logs = decodeLogsValue(value.get());
				for( auto const& log : logs.first ) {
					if (log.second == NetworkAddress() || addressExcluded(exclusions, log.second)) {
						ok = false;
						inProgressExclusion.insert(log.second);
					}
				}
				for( auto const& log : logs.second ) {
					if (log.second == NetworkAddress() || addressExcluded(exclusions, log.second)) {
						ok = false;
						inProgressExclusion.insert(log.second);
					}
				}
			}

			if (ok) return inProgressExclusion;
			if (!waitForAllExcluded) break;

			wait( delayJittered( 1.0 ) );  // SOMEDAY: watches!
		} catch (Error& e) {
			wait( tr.onError(e) );
		}
	}

	return inProgressExclusion;
}

ACTOR Future<UID> mgmtSnapCreate(Database cx, StringRef snapCmd) {
	state UID snapUID = deterministicRandom()->randomUniqueID();
	try {
		wait(snapCreate(cx, snapCmd, snapUID));
		TraceEvent("SnapCreateSucceeded").detail("snapUID", snapUID);
		return snapUID;
	} catch (Error& e) {
		TraceEvent(SevWarn, "SnapCreateFailed").detail("snapUID", snapUID).error(e);
		throw;
	}
}

ACTOR Future<Void> waitForFullReplication( Database cx ) {
	state ReadYourWritesTransaction tr(cx);
	loop {
		try {
			tr.setOption( FDBTransactionOptions::READ_SYSTEM_KEYS );
			tr.setOption( FDBTransactionOptions::PRIORITY_SYSTEM_IMMEDIATE );
			tr.setOption( FDBTransactionOptions::LOCK_AWARE );

			Standalone<RangeResultRef> confResults = wait( tr.getRange(configKeys, CLIENT_KNOBS->TOO_MANY) );
			ASSERT( !confResults.more && confResults.size() < CLIENT_KNOBS->TOO_MANY );
			state DatabaseConfiguration config;
			config.fromKeyValues((VectorRef<KeyValueRef>) confResults);

			state std::vector<Future<Optional<Value>>> replicasFutures;
			for(auto& region : config.regions) {
				replicasFutures.push_back(tr.get(datacenterReplicasKeyFor(region.dcId)));
			}
			wait( waitForAll(replicasFutures) );

			state std::vector<Future<Void>> watchFutures;
			for(int i = 0; i < config.regions.size(); i++) {
				if( !replicasFutures[i].get().present() || decodeDatacenterReplicasValue(replicasFutures[i].get().get()) < config.storageTeamSize ) {
					watchFutures.push_back(tr.watch(datacenterReplicasKeyFor(config.regions[i].dcId)));
				}
			}

			if( !watchFutures.size() || (config.usableRegions == 1 && watchFutures.size() < config.regions.size())) {
				return Void();
			}

			wait( tr.commit() );
			wait( waitForAny(watchFutures) );
			tr.reset();
		} catch (Error& e) {
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<Void> timeKeeperSetDisable(Database cx) {
	loop {
		state Transaction tr(cx);
		try {
			tr.setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
			tr.setOption(FDBTransactionOptions::LOCK_AWARE);
			tr.set(timeKeeperDisableKey, StringRef());
			wait(tr.commit());
			return Void();
		} catch (Error &e) {
			wait(tr.onError(e));
		}
	}
}

ACTOR Future<Void> lockDatabase( Transaction* tr, UID id ) {
	tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
	tr->setOption(FDBTransactionOptions::LOCK_AWARE);
	Optional<Value> val = wait( tr->get(databaseLockedKey) );

	if(val.present()) {
		if(BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()) == id) {
			return Void();
		} else {
			//TraceEvent("DBA_LockLocked").detail("Expecting", id).detail("Lock", BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()));
			throw database_locked();
		}
	}

	tr->atomicOp(databaseLockedKey, BinaryWriter::toValue(id, Unversioned()).withPrefix(LiteralStringRef("0123456789")).withSuffix(LiteralStringRef("\x00\x00\x00\x00")), MutationRef::SetVersionstampedValue);
	tr->addWriteConflictRange(normalKeys);
	return Void();
}

ACTOR Future<Void> lockDatabase( Reference<ReadYourWritesTransaction> tr, UID id ) {
	tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
	tr->setOption(FDBTransactionOptions::LOCK_AWARE);
	Optional<Value> val = wait( tr->get(databaseLockedKey) );

	if(val.present()) {
		if(BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()) == id) {
			return Void();
		} else {
			//TraceEvent("DBA_LockLocked").detail("Expecting", id).detail("Lock", BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()));
			throw database_locked();
		}
	}

	tr->atomicOp(databaseLockedKey, BinaryWriter::toValue(id, Unversioned()).withPrefix(LiteralStringRef("0123456789")).withSuffix(LiteralStringRef("\x00\x00\x00\x00")), MutationRef::SetVersionstampedValue);
	tr->addWriteConflictRange(normalKeys);
	return Void();
}

ACTOR Future<Void> lockDatabase( Database cx, UID id ) {
	state Transaction tr(cx);
	loop {
		try {
			wait( lockDatabase(&tr, id) );
			wait( tr.commit() );
			return Void();
		} catch( Error &e ) {
			if(e.code() == error_code_database_locked)
				throw e;
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<Void> unlockDatabase( Transaction* tr, UID id ) {
	tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
	tr->setOption(FDBTransactionOptions::LOCK_AWARE);
	Optional<Value> val = wait( tr->get(databaseLockedKey) );

	if(!val.present())
		return Void();

	if(val.present() && BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()) != id) {
		//TraceEvent("DBA_UnlockLocked").detail("Expecting", id).detail("Lock", BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()));
		throw database_locked();
	}

	tr->clear(singleKeyRange(databaseLockedKey));
	return Void();
}

ACTOR Future<Void> unlockDatabase( Reference<ReadYourWritesTransaction> tr, UID id ) {
	tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
	tr->setOption(FDBTransactionOptions::LOCK_AWARE);
	Optional<Value> val = wait( tr->get(databaseLockedKey) );

	if(!val.present())
		return Void();

	if(val.present() && BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()) != id) {
		//TraceEvent("DBA_UnlockLocked").detail("Expecting", id).detail("Lock", BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()));
		throw database_locked();
	}

	tr->clear(singleKeyRange(databaseLockedKey));
	return Void();
}

ACTOR Future<Void> unlockDatabase( Database cx, UID id ) {
	state Transaction tr(cx);
	loop {
		try {
			wait( unlockDatabase(&tr, id) );
			wait( tr.commit() );
			return Void();
		} catch( Error &e ) {
			if(e.code() == error_code_database_locked)
				throw e;
			wait( tr.onError(e) );
		}
	}
}

ACTOR Future<Void> checkDatabaseLock( Transaction* tr, UID id ) {
	tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
	tr->setOption(FDBTransactionOptions::LOCK_AWARE);
	Optional<Value> val = wait( tr->get(databaseLockedKey) );

	if (val.present() && BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()) != id) {
		//TraceEvent("DBA_CheckLocked").detail("Expecting", id).detail("Lock", BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned())).backtrace();
		throw database_locked();
	}

	return Void();
}

ACTOR Future<Void> checkDatabaseLock( Reference<ReadYourWritesTransaction> tr, UID id ) {
	tr->setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
	tr->setOption(FDBTransactionOptions::LOCK_AWARE);
	Optional<Value> val = wait( tr->get(databaseLockedKey) );

	if (val.present() && BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned()) != id) {
		//TraceEvent("DBA_CheckLocked").detail("Expecting", id).detail("Lock", BinaryReader::fromStringRef<UID>(val.get().substr(10), Unversioned())).backtrace();
		throw database_locked();
	}

	return Void();
}

ACTOR Future<Void> forceRecovery( Reference<ClusterConnectionFile> clusterFile, Key dcId ) {
	state Reference<AsyncVar<Optional<ClusterInterface>>> clusterInterface(new AsyncVar<Optional<ClusterInterface>>);
	state Future<Void> leaderMon = monitorLeader<ClusterInterface>(clusterFile, clusterInterface);

	loop {
		choose {
			when ( wait( clusterInterface->get().present() ? brokenPromiseToNever( clusterInterface->get().get().forceRecovery.getReply( ForceRecoveryRequest(dcId) ) ) : Never() ) ) {
				return Void();
			}
			when ( wait( clusterInterface->onChange() )) {}
		}
	}
}

ACTOR Future<Void> waitForPrimaryDC( Database cx, StringRef dcId ) {
	state ReadYourWritesTransaction tr(cx);

	loop {
		try {
			tr.setOption(FDBTransactionOptions::ACCESS_SYSTEM_KEYS);
			Optional<Value> res = wait( tr.get(primaryDatacenterKey) );
			if(res.present() && res.get() == dcId) {
				return Void();
			}

			state Future<Void> watchFuture = tr.watch(primaryDatacenterKey);
			wait(tr.commit());
			wait(watchFuture);
			tr.reset();
		} catch (Error& e) {
			wait( tr.onError(e) );
		}
	}
}

json_spirit::Value_type normJSONType(json_spirit::Value_type type) {
	if (type == json_spirit::int_type)
		return json_spirit::real_type;
	return type;
}

void schemaCoverage( std::string const& spath, bool covered ) {
	static std::map<bool, std::set<std::string>> coveredSchemaPaths;

	if( coveredSchemaPaths[covered].insert(spath).second ) {
		TraceEvent ev(SevInfo, "CodeCoverage");
		ev.detail("File", "documentation/StatusSchema.json/" + spath).detail("Line", 0);
		if (!covered)
			ev.detail("Covered", 0);
	}
}

bool schemaMatch( json_spirit::mValue const& schemaValue, json_spirit::mValue const& resultValue, std::string& errorStr, Severity sev, bool checkCoverage, std::string path, std::string schemaPath ) {
	// Returns true if everything in `result` is permitted by `schema`
	bool ok = true;

	try {
		if(normJSONType(schemaValue.type()) != normJSONType(resultValue.type())) {
			errorStr += format("ERROR: Incorrect value type for key `%s'\n", path.c_str());
			TraceEvent(sev, "SchemaMismatch").detail("Path", path).detail("SchemaType", schemaValue.type()).detail("ValueType", resultValue.type());
			return false;
		}

		if(resultValue.type() == json_spirit::obj_type) {
			auto& result = resultValue.get_obj();
			auto& schema = schemaValue.get_obj();

			for(auto& rkv : result) {
				auto& key = rkv.first;
				auto& rv = rkv.second;
				std::string kpath = path + "." + key;
				std::string spath = schemaPath + "." + key;

				if(checkCoverage) {
					schemaCoverage(spath);
				}

				if(!schema.count(key)) {
					errorStr += format("ERROR: Unknown key `%s'\n", kpath.c_str());
					TraceEvent(sev, "SchemaMismatch").detail("Path", kpath).detail("SchemaPath", spath);
					ok = false;
					continue;
				}
				auto& sv = schema.at(key);

				if(sv.type() == json_spirit::obj_type && sv.get_obj().count("$enum")) {
					auto& enum_values = sv.get_obj().at("$enum").get_array();

					bool any_match = false;
					for(auto& enum_item : enum_values)
						if(enum_item == rv) {
							any_match = true;
							if(checkCoverage) {
								schemaCoverage(spath + ".$enum." + enum_item.get_str());
							}
							break;
						}
					if(!any_match) {
						errorStr += format("ERROR: Unknown value `%s' for key `%s'\n", json_spirit::write_string(rv).c_str(), kpath.c_str());
						TraceEvent(sev, "SchemaMismatch").detail("Path", kpath).detail("SchemaEnumItems", enum_values.size()).detail("Value", json_spirit::write_string(rv));
						if(checkCoverage) {
							schemaCoverage(spath + ".$enum." + json_spirit::write_string(rv));
						}
						ok = false;
					}
				} else if(sv.type() == json_spirit::obj_type && sv.get_obj().count("$map")) {
					if(rv.type() != json_spirit::obj_type) {
						errorStr += format("ERROR: Expected an object as the value for key `%s'\n", kpath.c_str());
						TraceEvent(sev, "SchemaMismatch").detail("Path", kpath).detail("SchemaType", sv.type()).detail("ValueType", rv.type());
						ok = false;
						continue;
					}
					if(sv.get_obj().at("$map").type() != json_spirit::obj_type) {
						continue;
					}
					auto& schemaVal = sv.get_obj().at("$map");
					auto& valueObj = rv.get_obj();

					if(checkCoverage) {
						schemaCoverage(spath + ".$map");
					}

					for(auto& valuePair : valueObj) {
						auto vpath = kpath + "[" + valuePair.first + "]";
						auto upath = spath + ".$map";
						if (valuePair.second.type() != json_spirit::obj_type) {
							errorStr += format("ERROR: Expected an object for `%s'\n", vpath.c_str());
							TraceEvent(sev, "SchemaMismatch").detail("Path", vpath).detail("ValueType", valuePair.second.type());
							ok = false;
							continue;
						}
						if(!schemaMatch(schemaVal, valuePair.second, errorStr, sev, checkCoverage, vpath, upath)) {
							ok = false;
						}
					}
				} else {
					if(!schemaMatch(sv, rv, errorStr, sev, checkCoverage, kpath, spath)) {
						ok = false;
					}
				}
			}
		} else if(resultValue.type() == json_spirit::array_type) {
			auto& valueArray = resultValue.get_array();
			auto& schemaArray = schemaValue.get_array();
			if(!schemaArray.size()) {
				// An empty schema array means that the value array is required to be empty
				if(valueArray.size()) {
					errorStr += format("ERROR: Expected an empty array for key `%s'\n", path.c_str());
					TraceEvent(sev, "SchemaMismatch").detail("Path", path).detail("SchemaSize", schemaArray.size()).detail("ValueSize", valueArray.size());
					return false;
				}
			} else if(schemaArray.size() == 1) {
				// A one item schema array means that all items in the value must match the first item in the schema
				int index = 0;
				for(auto &valueItem : valueArray) {
					if(!schemaMatch(schemaArray[0], valueItem, errorStr, sev, checkCoverage, path + format("[%d]", index), schemaPath + "[0]")) {
						ok = false;
					}
					index++;
				}
			} else {
				ASSERT(false);  // Schema doesn't make sense
			}
		}
		return ok;
	} catch (std::exception& e) {
		TraceEvent(SevError, "SchemaMatchException").detail("What", e.what()).detail("Path", path).detail("SchemaPath", schemaPath);
		throw unknown_error();
	}
}

TEST_CASE("/ManagementAPI/AutoQuorumChange/checkLocality") {
	wait(Future<Void>(Void()));

	std::vector<ProcessData> workers;
	std::vector<NetworkAddress> chosen;
	std::set<AddressExclusion> excluded;
	AutoQuorumChange change(5);

	for(int i = 0; i < 10; i++) {
		ProcessData data;
		auto dataCenter = std::to_string(i / 4 % 2);
		auto dataHall = dataCenter + std::to_string(i / 2 % 2);
		auto rack = dataHall + std::to_string(i % 2);
		auto machineId = rack + std::to_string(i);
		data.locality.set(LiteralStringRef("dcid"), StringRef(dataCenter));
		data.locality.set(LiteralStringRef("data_hall"), StringRef(dataHall));
		data.locality.set(LiteralStringRef("rack"), StringRef(rack));
		data.locality.set(LiteralStringRef("zoneid"), StringRef(rack));
		data.locality.set(LiteralStringRef("machineid"), StringRef(machineId));
		data.address.ip = IPAddress(i);

		workers.push_back(data);
	}

	auto noAssignIndex = deterministicRandom()->randomInt(0, workers.size());
	workers[noAssignIndex].processClass._class = ProcessClass::CoordinatorClass;

	change.addDesiredWorkers(chosen, workers, 5, excluded);
	std::map<StringRef, std::set<StringRef>> chosenValues;

	ASSERT(chosen.size() == 5);
	std::vector<StringRef> fields({
		LiteralStringRef("dcid"),
		LiteralStringRef("data_hall"),
		LiteralStringRef("zoneid"),
		LiteralStringRef("machineid")
	});
	for(auto worker = chosen.begin(); worker != chosen.end(); worker++) {
		ASSERT(worker->ip.toV4() < workers.size());
		LocalityData data = workers[worker->ip.toV4()].locality;
		for(auto field = fields.begin(); field != fields.end(); field++) {
			chosenValues[*field].insert(data.get(*field).get());
		}
	}

	ASSERT(chosenValues[LiteralStringRef("dcid")].size() == 2);
	ASSERT(chosenValues[LiteralStringRef("data_hall")].size() == 4);
	ASSERT(chosenValues[LiteralStringRef("zoneid")].size() == 5);
	ASSERT(chosenValues[LiteralStringRef("machineid")].size() == 5);
	ASSERT(std::find(chosen.begin(), chosen.end(), workers[noAssignIndex].address) != chosen.end());

	return Void();
}