SERVER-42827 Allow sessions collection to return OK for creating indexes if at least one shard returns OK and others return CannotImplicitlyCreateCollection

4 files changed, 38 insertions, 22 deletions

diff --git a/src/mongo/db/sessions_collection_config_server.cpp b/src/mongo/db/sessions_collection_config_server.cpp
index b9b339a5606..63e16f14321 100644
--- a/src/mongo/db/sessions_collection_config_server.cpp
+++ b/src/mongo/db/sessions_collection_config_server.cpp
@@ -79,11 +79,11 @@ Status SessionsCollectionConfigServer::_shardCollectionIfNeeded(OperationContext
 
 Status SessionsCollectionConfigServer::_generateIndexesIfNeeded(OperationContext* opCtx) {
     try {
-        scatterGatherOnlyVersionIfUnsharded(opCtx,
-                                            NamespaceString::kLogicalSessionsNamespace,
-                                            SessionsCollection::generateCreateIndexesCmd(),
-                                            ReadPreferenceSetting::get(opCtx),
-                                            Shard::RetryPolicy::kNoRetry);
+        dispatchCommandAssertCollectionExistsOnAtLeastOneShard(
+            opCtx,
+            NamespaceString::kLogicalSessionsNamespace,
+            SessionsCollection::generateCreateIndexesCmd());
+
         return Status::OK();
     } catch (const DBException& ex) {
         return ex.toStatus();
diff --git a/src/mongo/s/cluster_commands_helpers.cpp b/src/mongo/s/cluster_commands_helpers.cpp
index 7eead10ebfa..a2fd9e350b2 100644
--- a/src/mongo/s/cluster_commands_helpers.cpp
+++ b/src/mongo/s/cluster_commands_helpers.cpp
@@ -570,4 +570,27 @@ StatusWith<CachedCollectionRoutingInfo> getCollectionRoutingInfoForTxnCmd(
     return catalogCache->getCollectionRoutingInfoAt(opCtx, nss, atClusterTime.asTimestamp());
 }
 
+std::vector<AsyncRequestsSender::Response> dispatchCommandAssertCollectionExistsOnAtLeastOneShard(
+    OperationContext* opCtx, const NamespaceString& nss, const BSONObj& cmdObj) {
+    auto shardResponses = scatterGatherOnlyVersionIfUnsharded(
+        opCtx,
+        nss,
+        CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+        ReadPreferenceSetting::get(opCtx),
+        Shard::RetryPolicy::kNoRetry,
+        {ErrorCodes::CannotImplicitlyCreateCollection});
+
+    if (std::all_of(shardResponses.begin(), shardResponses.end(), [](const auto& response) {
+            return response.swResponse.getStatus().isOK() &&
+                getStatusFromCommandResult(response.swResponse.getValue().data) ==
+                ErrorCodes::CannotImplicitlyCreateCollection;
+        })) {
+        // Propagate the ExtraErrorInfo from the first response.
+        uassertStatusOK(
+            getStatusFromCommandResult(shardResponses.front().swResponse.getValue().data));
+    }
+
+    return shardResponses;
+}
+
 }  // namespace mongo
diff --git a/src/mongo/s/cluster_commands_helpers.h b/src/mongo/s/cluster_commands_helpers.h
index 1e5ee9685fc..2a50e01d2a3 100644
--- a/src/mongo/s/cluster_commands_helpers.h
+++ b/src/mongo/s/cluster_commands_helpers.h
@@ -233,4 +233,12 @@ std::set<ShardId> getTargetedShardsForQuery(OperationContext* opCtx,
 StatusWith<CachedCollectionRoutingInfo> getCollectionRoutingInfoForTxnCmd(
     OperationContext* opCtx, const NamespaceString& nss);
 
+/**
+ * Utility for dispatching a command on a namespace that is sent to all shards. If all shards return
+ * CannotImplicitlyCreateCollection, will throw. If at least one shard succeeds, will ignore
+ * CannotImplicitlyCreateCollection errors.
+ */
+std::vector<AsyncRequestsSender::Response> dispatchCommandAssertCollectionExistsOnAtLeastOneShard(
+    OperationContext* opCtx, const NamespaceString& nss, const BSONObj& cmdObj);
+
 }  // namespace mongo
diff --git a/src/mongo/s/commands/cluster_create_indexes_cmd.cpp b/src/mongo/s/commands/cluster_create_indexes_cmd.cpp
index 31e0d36625a..7ec58e26000 100644
--- a/src/mongo/s/commands/cluster_create_indexes_cmd.cpp
+++ b/src/mongo/s/commands/cluster_create_indexes_cmd.cpp
@@ -73,23 +73,8 @@ public:
 
         createShardDatabase(opCtx, dbName);
 
-        auto shardResponses = scatterGatherOnlyVersionIfUnsharded(
-            opCtx,
-            nss,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
-            ReadPreferenceSetting::get(opCtx),
-            Shard::RetryPolicy::kNoRetry,
-            {ErrorCodes::CannotImplicitlyCreateCollection});
-
-        if (std::all_of(shardResponses.begin(), shardResponses.end(), [](const auto& response) {
-                return response.swResponse.getStatus().isOK() &&
-                    getStatusFromCommandResult(response.swResponse.getValue().data) ==
-                    ErrorCodes::CannotImplicitlyCreateCollection;
-            })) {
-            // Propagate the ExtraErrorInfo from the first response.
-            uassertStatusOK(
-                getStatusFromCommandResult(shardResponses.front().swResponse.getValue().data));
-        }
+        auto shardResponses =
+            dispatchCommandAssertCollectionExistsOnAtLeastOneShard(opCtx, nss, cmdObj);
 
         return appendRawResponses(opCtx,
                                   &errmsg,