SERVER-31184 Make servers automatically set up config.system.sessions

1 files changed, 23 insertions, 0 deletions

diff --git a/src/mongo/db/sessions_collection_sharded.cpp b/src/mongo/db/sessions_collection_sharded.cpp
index bbcf195d8dd..de7699eb962 100644
--- a/src/mongo/db/sessions_collection_sharded.cpp
+++ b/src/mongo/db/sessions_collection_sharded.cpp
@@ -35,7 +35,10 @@
 #include "mongo/db/query/canonical_query.h"
 #include "mongo/db/query/query_request.h"
 #include "mongo/db/sessions_collection_rs.h"
+#include "mongo/rpc/get_status_from_command_result.h"
+#include "mongo/s/catalog_cache.h"
 #include "mongo/s/commands/cluster_write.h"
+#include "mongo/s/grid.h"
 #include "mongo/s/query/cluster_find.h"
 #include "mongo/s/write_ops/batch_write_exec.h"
 #include "mongo/s/write_ops/batched_command_request.h"
@@ -52,6 +55,26 @@ BSONObj lsidQuery(const LogicalSessionId& lsid) {
 
 }  // namespace
 
+Status SessionsCollectionSharded::_checkCacheForSessionsCollection(OperationContext* opCtx) {
+    // If the collection doesn't exist, fail. Only the config servers generate it.
+    auto res = Grid::get(opCtx)->catalogCache()->getShardedCollectionRoutingInfoWithRefresh(
+        opCtx, NamespaceString(SessionsCollection::kSessionsFullNS.toString()));
+    if (!res.isOK()) {
+        return res.getStatus();
+    }
+
+    auto routingInfo = res.getValue();
+    if (routingInfo.cm()) {
+        return Status::OK();
+    }
+
+    return {ErrorCodes::NamespaceNotFound, "config.system.sessions is not yet sharded"};
+}
+
+Status SessionsCollectionSharded::setupSessionsCollection(OperationContext* opCtx) {
+    return _checkCacheForSessionsCollection(opCtx);
+}
+
 Status SessionsCollectionSharded::refreshSessions(OperationContext* opCtx,
                                                   const LogicalSessionRecordSet& sessions) {
     auto send = [&](BSONObj toSend) {