From e898e59d18abc3d60a5690d45415586c62492bc7 Mon Sep 17 00:00:00 2001
From: "A.J. Beamon" <aj.beamon@snowflake.com>
Date: Tue, 1 Mar 2022 08:27:00 -0800
Subject: [PATCH] Fix merge issue that caused tenant serialization problems.
 Fix case where arena was passed by value rather than reference. Watches
 should check the tenant map at the latest version rather than the watch
 version.

---
 fdbclient/Tenant.h                |  1 -
 fdbserver/storageserver.actor.cpp | 26 ++++++++++++++++----------
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/fdbclient/Tenant.h b/fdbclient/Tenant.h
index 1d14ea3b12..7c5750e0dd 100644
--- a/fdbclient/Tenant.h
+++ b/fdbclient/Tenant.h
@@ -65,7 +65,6 @@ public:
 	template <class Ar>
 	void serialize(Ar& ar) {
 		KeyRef subspace;
-		serializer(ar, id);
 		if (ar.isDeserializing) {
 			serializer(ar, id, subspace);
 			if (id >= 0) {
diff --git a/fdbserver/storageserver.actor.cpp b/fdbserver/storageserver.actor.cpp
index 9ca5013028..13f744ef18 100644
--- a/fdbserver/storageserver.actor.cpp
+++ b/fdbserver/storageserver.actor.cpp
@@ -2127,7 +2127,7 @@ ACTOR Future<Void> getShardStateQ(StorageServer* data, GetShardStateRequest req)
 	return Void();
 }
 
-KeyRef addPrefix(KeyRef const& key, Optional<Key> prefix, Arena arena) {
+KeyRef addPrefix(KeyRef const& key, Optional<Key> prefix, Arena& arena) {
 	if (prefix.present()) {
 		return key.withPrefix(prefix.get(), arena);
 	} else {
@@ -6855,7 +6855,7 @@ ACTOR Future<Void> watchValueWaitForVersion(StorageServer* self,
 	getCurrentLineage()->modify(&TransactionLineage::txID) = req.spanContext.first();
 	try {
 		wait(success(waitForVersionNoTooOld(self, req.version)));
-		Optional<TenantMapEntry> entry = self->getTenantEntry(req.version, req.tenantInfo.name);
+		Optional<TenantMapEntry> entry = self->getTenantEntry(latestVersion, req.tenantInfo.name);
 		if (entry.present()) {
 			req.key = req.key.withPrefix(entry.get().prefix);
 		}
@@ -6876,21 +6876,24 @@ ACTOR Future<Void> serveWatchValueRequestsImpl(StorageServer* self, FutureStream
 		state Span span("SS:serveWatchValueRequestsImpl"_loc, { req.spanContext });
 		getCurrentLineage()->modify(&TransactionLineage::txID) = req.spanContext.first();
 
-		if (!metadata.isValid()) { // case 1: no watch set for the current key
+		// case 1: no watch set for the current key
+		if (!metadata.isValid()) {
 			metadata = makeReference<ServerWatchMetadata>(req.key, req.value, req.version, req.tags, req.debugID);
 			KeyRef key = self->setWatchMetadata(metadata);
 			metadata->watch_impl = forward(watchWaitForValueChange(self, span.context, key), metadata->versionPromise);
 			self->actors.add(watchValueSendReply(self, req, metadata->versionPromise.getFuture(), span.context));
-		} else if (metadata->value ==
-		           req.value) { // case 2: there is a watch in the map and it has the same value so just update version
+		}
+		// case 2: there is a watch in the map and it has the same value so just update version
+		else if (metadata->value == req.value) {
 			if (req.version > metadata->version) {
 				metadata->version = req.version;
 				metadata->tags = req.tags;
 				metadata->debugID = req.debugID;
 			}
 			self->actors.add(watchValueSendReply(self, req, metadata->versionPromise.getFuture(), span.context));
-		} else if (req.version > metadata->version) { // case 3: version in map has a lower version so trigger watch and
-			                                          // create a new entry in map
+		}
+		// case 3: version in map has a lower version so trigger watch and create a new entry in map
+		else if (req.version > metadata->version) {
 			self->deleteWatchMetadata(req.key.contents());
 			metadata->versionPromise.send(req.version);
 			metadata->watch_impl.cancel();
@@ -6900,11 +6903,14 @@ ACTOR Future<Void> serveWatchValueRequestsImpl(StorageServer* self, FutureStream
 			metadata->watch_impl = forward(watchWaitForValueChange(self, span.context, key), metadata->versionPromise);
 
 			self->actors.add(watchValueSendReply(self, req, metadata->versionPromise.getFuture(), span.context));
-		} else if (req.version <
-		           metadata->version) { // case 4: version in the map is higher so immediately trigger watch
+		}
+		// case 4: version in the map is higher so immediately trigger watch
+		else if (req.version < metadata->version) {
 			TEST(true); // watch version in map is higher so trigger watch (case 4)
 			req.reply.send(WatchValueReply{ metadata->version });
-		} else { // case 5: watch value differs but their versions are the same (rare case) so check with the SS
+		}
+		// case 5: watch value differs but their versions are the same (rare case) so check with the SS
+		else {
 			TEST(true); // watch version in the map is the same but value is different (case 5)
 			loop {
 				try {