SERVER-31520 metadata commands on mongos should transparently pass config server response back to client

Author: EshaMaharishi

src/mongo/s/commands/cluster_add_shard_cmd.cpp

@@ -41,6 +41,7 @@
 #include "mongo/s/grid.h"
 #include "mongo/s/request_types/add_shard_request_type.h"
 #include "mongo/util/log.h"
+#include "mongo/util/scopeguard.h"
 
 namespace mongo {
 
@@ -86,30 +87,22 @@ class AddShardCmd : public BasicCommand {
                      BSONObjBuilder& result) {
         auto parsedRequest = uassertStatusOK(AddShardRequest::parseFromMongosCommand(cmdObj));
 
+        // Force a reload of this node's shard list cache at the end of this command.
+        ON_BLOCK_EXIT([opCtx] {
+            if (!Grid::get(opCtx)->shardRegistry()->reload(opCtx)) {
+                Grid::get(opCtx)->shardRegistry()->reload(opCtx);
+            }
+        });
+
         auto configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
-        auto cmdResponseStatus = uassertStatusOK(
+        auto cmdResponse = uassertStatusOK(
             configShard->runCommandWithFixedRetryAttempts(opCtx,
                                                           kPrimaryOnlyReadPreference,
                                                           "admin",
                                                           parsedRequest.toCommandForConfig(),
                                                           Shard::RetryPolicy::kIdempotent));
-        uassertStatusOK(cmdResponseStatus.commandStatus);
-
-        string shardAdded;
-        uassertStatusOK(
-            bsonExtractStringField(cmdResponseStatus.response, kShardAdded, &shardAdded));
-        result << "shardAdded" << shardAdded;
-
-        // Ensure the added shard is visible to this process.
-        auto shardRegistry = Grid::get(opCtx)->shardRegistry();
-        if (!shardRegistry->getShard(opCtx, shardAdded).isOK()) {
-            return appendCommandStatus(result,
-                                       {ErrorCodes::OperationFailed,
-                                        "Could not find shard metadata for shard after adding it. "
-                                        "This most likely indicates that the shard was removed "
-                                        "immediately after it was added."});
-        }
 
+        Command::filterCommandReplyForPassthrough(cmdResponse.response, &result);
         return true;
     }
 

src/mongo/s/commands/cluster_enable_sharding_cmd.cpp

@@ -99,19 +99,14 @@ class EnableShardingCmd : public ErrmsgCommandDeprecated {
         ON_BLOCK_EXIT([opCtx, db] { Grid::get(opCtx)->catalogCache()->purgeDatabase(db); });
 
         auto configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
-        auto cmdResponseStatus = uassertStatusOK(configShard->runCommandWithFixedRetryAttempts(
+        auto cmdResponse = uassertStatusOK(configShard->runCommandWithFixedRetryAttempts(
             opCtx,
             ReadPreferenceSetting(ReadPreference::PrimaryOnly),
             "admin",
             Command::appendPassthroughFields(cmdObj, BSON("_configsvrEnableSharding" << db)),
             Shard::RetryPolicy::kIdempotent));
-        uassertStatusOK(cmdResponseStatus.commandStatus);
-
-        if (!cmdResponseStatus.writeConcernStatus.isOK()) {
-            appendWriteConcernErrorToCmdResponse(
-                configShard->getId(), cmdResponseStatus.response["writeConcernError"], result);
-        }
 
+        Command::filterCommandReplyForPassthrough(cmdResponse.response, &result);
         return true;
     }
 

src/mongo/s/commands/cluster_move_primary_cmd.cpp

@@ -112,19 +112,14 @@ class MoveDatabasePrimaryCommand : public BasicCommand {
 
         auto configShard = Grid::get(opCtx)->shardRegistry()->getConfigShard();
 
-        auto cmdResponseStatus = uassertStatusOK(configShard->runCommandWithFixedRetryAttempts(
+        auto cmdResponse = uassertStatusOK(configShard->runCommandWithFixedRetryAttempts(
             opCtx,
             ReadPreferenceSetting(ReadPreference::PrimaryOnly),
             "admin",
             Command::appendPassthroughFields(cmdObj, configMovePrimaryRequest.toBSON()),
             Shard::RetryPolicy::kIdempotent));
-        uassertStatusOK(cmdResponseStatus.commandStatus);
-
-        if (!cmdResponseStatus.writeConcernStatus.isOK()) {
-            appendWriteConcernErrorToCmdResponse(
-                configShard->getId(), cmdResponseStatus.response["writeConcernError"], result);
-        }
 
+        Command::filterCommandReplyForPassthrough(cmdResponse.response, &result);
         return true;
     }
 

src/mongo/s/commands/cluster_shard_collection_cmd.cpp

@@ -132,13 +132,7 @@ class ShardCollectionCmd : public BasicCommand {
             Command::appendPassthroughFields(cmdObj, configShardCollRequest.toBSON()),
             Shard::RetryPolicy::kIdempotent));
 
-        uassertStatusOK(cmdResponse.commandStatus);
-
-        if (!cmdResponse.writeConcernStatus.isOK()) {
-            appendWriteConcernErrorToCmdResponse(
-                configShard->getId(), cmdResponse.response["writeConcernError"], result);
-        }
-
+        Command::filterCommandReplyForPassthrough(cmdResponse.response, &result);
         return true;
     }