SERVER-33516 Make _configsvrCreateCollection take the db distlock to prevent conncurrent movePrimary

3 files changed, 35 insertions, 5 deletions

diff --git a/jstests/concurrency/fsm_workloads/view_catalog.js b/jstests/concurrency/fsm_workloads/view_catalog.js
index 31ed0072bb3..ebb44905bf4 100644
--- a/jstests/concurrency/fsm_workloads/view_catalog.js
+++ b/jstests/concurrency/fsm_workloads/view_catalog.js
@@ -79,9 +79,18 @@ var $config = (function() {
         dropCollections(db, pattern);
     }
 
+    // This test performs createCollection concurrently from many threads, and createCollection on a
+    // sharded cluster takes a distributed lock. Since a distributed lock is acquired by repeatedly
+    // attempting to grab the lock every half second for 20 seconds (a max of 40 attempts), it's
+    // possible that some thread will be starved by the other threads and fail to grab the lock
+    // after 40 attempts. To reduce the likelihood of this, we choose threadCount and iterations so
+    // that threadCount * iterations < 40.
+    // The threadCount and iterations can be increased once PM-697 ("Remove all usages of
+    // distributed lock") is complete.
+
     return {
-        threadCount: 10,
-        iterations: 100,
+        threadCount: 5,
+        iterations: 5,
         data: data,
         states: states,
         transitions: transitions,
diff --git a/jstests/concurrency/fsm_workloads/view_catalog_cycle_with_drop.js b/jstests/concurrency/fsm_workloads/view_catalog_cycle_with_drop.js
index f5d82b98fb6..9768ec7dee5 100644
--- a/jstests/concurrency/fsm_workloads/view_catalog_cycle_with_drop.js
+++ b/jstests/concurrency/fsm_workloads/view_catalog_cycle_with_drop.js
@@ -97,9 +97,18 @@ var $config = (function() {
         dropCollections(db, pattern);
     }
 
+    // This test performs createCollection concurrently from many threads, and createCollection on a
+    // sharded cluster takes a distributed lock. Since a distributed lock is acquired by repeatedly
+    // attempting to grab the lock every half second for 20 seconds (a max of 40 attempts), it's
+    // possible that some thread will be starved by the other threads and fail to grab the lock
+    // after 40 attempts. To reduce the likelihood of this, we choose threadCount and iterations so
+    // that threadCount * iterations < 40.
+    // The threadCount and iterations can be increased once PM-697 ("Remove all usages of
+    // distributed lock") is complete.
+
     return {
-        threadCount: 10,
-        iterations: 100,
+        threadCount: 5,
+        iterations: 5,
         data: data,
         states: states,
         startState: 'readFromView',
diff --git a/src/mongo/db/s/config/configsvr_create_collection_command.cpp b/src/mongo/db/s/config/configsvr_create_collection_command.cpp
index 7eba3758208..8745aeff00a 100644
--- a/src/mongo/db/s/config/configsvr_create_collection_command.cpp
+++ b/src/mongo/db/s/config/configsvr_create_collection_command.cpp
@@ -88,8 +88,12 @@ public:
         return Status::OK();
     }
 
+    std::string parseNs(const std::string& dbname, const BSONObj& cmdObj) const override {
+        return CommandHelpers::parseNsFullyQualified(dbname, cmdObj);
+    }
+
     bool run(OperationContext* opCtx,
-             const std::string& dbname,
+             const std::string& dbname_unused,
              const BSONObj& cmdObj,
              BSONObjBuilder& result) override {
 
@@ -113,6 +117,14 @@ public:
             uassertStatusOK(options.parse(*requestOptions));
         }
 
+        auto const catalogClient = Grid::get(opCtx)->catalogClient();
+        const NamespaceString nss(parseNs(dbname_unused, cmdObj));
+
+        auto dbDistLock = uassertStatusOK(catalogClient->getDistLockManager()->lock(
+            opCtx, nss.db(), "createCollection", DistLockManager::kDefaultLockTimeout));
+        auto collDistLock = uassertStatusOK(catalogClient->getDistLockManager()->lock(
+            opCtx, nss.ns(), "createCollection", DistLockManager::kDefaultLockTimeout));
+
         ShardingCatalogManager::get(opCtx)->createCollection(opCtx, createCmd.getNs(), options);
 
         return true;