SERVER-68161 Do not wait for ShardRegistry reload at startup

7 files changed, 14 insertions, 44 deletions

diff --git a/src/mongo/db/mongod_main.cpp b/src/mongo/db/mongod_main.cpp
index 5b6f0b88d1c..6b4ba9d46bd 100644
--- a/src/mongo/db/mongod_main.cpp
+++ b/src/mongo/db/mongod_main.cpp
@@ -625,11 +625,10 @@ ExitCode _initAndListen(ServiceContext* serviceContext, int listenPort) {
     auto shardingInitialized = ShardingInitializationMongoD::get(startupOpCtx.get())
                                    ->initializeShardingAwarenessIfNeeded(startupOpCtx.get());
     if (shardingInitialized) {
-        auto status = waitForShardRegistryReload(startupOpCtx.get());
+        auto status = loadGlobalSettingsFromConfigServer(startupOpCtx.get());
         if (!status.isOK()) {
             LOGV2(20545,
-                  "Error loading shard registry at startup {error}",
-                  "Error loading shard registry at startup",
+                  "Error loading global settings from config server at startup",
                   "error"_attr = redact(status));
         }
     }
diff --git a/src/mongo/db/s/sharding_initialization_mongod.cpp b/src/mongo/db/s/sharding_initialization_mongod.cpp
index 9d423f65057..ff2b685cb93 100644
--- a/src/mongo/db/s/sharding_initialization_mongod.cpp
+++ b/src/mongo/db/s/sharding_initialization_mongod.cpp
@@ -495,11 +495,10 @@ void ShardingInitializationMongoD::onInitialDataAvailable(OperationContext* opCt
     // This function may take the global lock.
     auto shardingInitialized = initializeShardingAwarenessIfNeeded(opCtx);
     if (shardingInitialized) {
-        auto status = waitForShardRegistryReload(opCtx);
+        auto status = loadGlobalSettingsFromConfigServer(opCtx);
         if (!status.isOK()) {
             LOGV2(6460100,
-                  "Error loading shard registry at startup {error}",
-                  "Error loading shard registry at startup",
+                  "Error loading global settings from config server at startup",
                   "error"_attr = redact(status));
         }
     }
diff --git a/src/mongo/s/client/shard_registry.cpp b/src/mongo/s/client/shard_registry.cpp
index 6070f3ea82d..a2a50cf5b20 100644
--- a/src/mongo/s/client/shard_registry.cpp
+++ b/src/mongo/s/client/shard_registry.cpp
@@ -413,20 +413,6 @@ std::unique_ptr<Shard> ShardRegistry::createConnection(const ConnectionString& c
     return _shardFactory->createUniqueShard(ShardId("<unnamed>"), connStr);
 }
 
-bool ShardRegistry::isUp() {
-    if (_isUp.load())
-        return true;
-
-    // Before the first lookup is completed, the latest cached value is either empty or it is
-    // associated to the default constructed time
-    const auto latestCached = _cache->peekLatestCached(_kSingleton);
-    if (latestCached && latestCached.getTime() != Time()) {
-        _isUp.store(true);
-        return true;
-    }
-    return false;
-}
-
 void ShardRegistry::toBSON(BSONObjBuilder* result) const {
     BSONObjBuilder map;
     BSONObjBuilder hosts;
diff --git a/src/mongo/s/client/shard_registry.h b/src/mongo/s/client/shard_registry.h
index 0a3b5d3bc09..d606a3c0976 100644
--- a/src/mongo/s/client/shard_registry.h
+++ b/src/mongo/s/client/shard_registry.h
@@ -271,12 +271,6 @@ public:
      */
     std::unique_ptr<Shard> createConnection(const ConnectionString& connStr) const;
 
-    /**
-     * The ShardRegistry is "up" once a successful lookup from the config servers has been
-     * completed.
-     */
-    bool isUp();
-
     void toBSON(BSONObjBuilder* result) const;
 
     /**
diff --git a/src/mongo/s/mongos_main.cpp b/src/mongo/s/mongos_main.cpp
index 55a705eb346..81869a5d08a 100644
--- a/src/mongo/s/mongos_main.cpp
+++ b/src/mongo/s/mongos_main.cpp
@@ -158,9 +158,6 @@ Status waitForSigningKeys(OperationContext* opCtx) {
     auto const shardRegistry = Grid::get(opCtx)->shardRegistry();
 
     while (true) {
-        // This should be true when shard registry is up
-        invariant(shardRegistry->isUp());
-
         auto configCS = shardRegistry->getConfigServerConnectionString();
         auto rsm = ReplicaSetMonitor::get(configCS.getSetName());
         // mongod will set minWireVersion == maxWireVersion for hello requests from
@@ -443,7 +440,7 @@ Status initializeSharding(OperationContext* opCtx) {
         return status;
     }
 
-    status = waitForShardRegistryReload(opCtx);
+    status = loadGlobalSettingsFromConfigServer(opCtx);
     if (!status.isOK()) {
         return status;
     }
diff --git a/src/mongo/s/sharding_initialization.cpp b/src/mongo/s/sharding_initialization.cpp
index 94ee8465ad1..b526895db1e 100644
--- a/src/mongo/s/sharding_initialization.cpp
+++ b/src/mongo/s/sharding_initialization.cpp
@@ -220,7 +220,7 @@ void loadCWWCFromConfigServerForReplication(OperationContext* opCtx) {
     repl::ReplicationCoordinator::get(opCtx)->recordIfCWWCIsSetOnConfigServerOnStartup(opCtx);
 }
 
-Status waitForShardRegistryReload(OperationContext* opCtx) {
+Status loadGlobalSettingsFromConfigServer(OperationContext* opCtx) {
     if (serverGlobalParams.clusterRole == ClusterRole::ConfigServer) {
         return Status::OK();
     }
@@ -236,24 +236,19 @@ Status waitForShardRegistryReload(OperationContext* opCtx) {
                 opCtx, repl::ReadConcernLevel::kMajorityReadConcern));
             // Assert will be raised on failure to talk to config server.
             loadCWWCFromConfigServerForReplication(opCtx);
-            if (Grid::get(opCtx)->shardRegistry()->isUp()) {
-                return Status::OK();
-            }
-            sleepFor(kRetryInterval);
-            continue;
+            return Status::OK();
         } catch (const DBException& ex) {
             Status status = ex.toStatus();
-            LOGV2_WARNING(
-                23834,
-                "Error {error} initializing sharding state, sleeping for 2 seconds and retrying",
-                "Error initializing sharding state, sleeping for 2 seconds and retrying",
-                "error"_attr = status);
+            LOGV2_WARNING(23834,
+                          "Error loading global settings from config server. Sleeping for 2 "
+                          "seconds and retrying",
+                          "error"_attr = status);
             sleepFor(kRetryInterval);
             continue;
         }
     }
 
-    return {ErrorCodes::ShutdownInProgress, "aborting shard loading attempt"};
+    return {ErrorCodes::ShutdownInProgress, "aborted loading global settings from config server"};
 }
 
 void preCacheMongosRoutingInfo(OperationContext* opCtx) {
diff --git a/src/mongo/s/sharding_initialization.h b/src/mongo/s/sharding_initialization.h
index 2dbc3ae470b..1d35fc601d2 100644
--- a/src/mongo/s/sharding_initialization.h
+++ b/src/mongo/s/sharding_initialization.h
@@ -72,10 +72,10 @@ Status initializeGlobalShardingState(OperationContext* opCtx,
                                      boost::optional<size_t> taskExecutorPoolSize);
 
 /**
- * Loads cluster ID and waits for the reload of the Shard Registry.
+ * Loads global settings from config server such as cluster ID and default write concern.
  */
 
-Status waitForShardRegistryReload(OperationContext* opCtx);
+Status loadGlobalSettingsFromConfigServer(OperationContext* opCtx);
 
 /**
  * Pre-caches mongod routing info for the calling process.