SERVER-25715 in shutdown, delete WiredTigerSessions w/o closing the underlying WT_SESSION

(cherry picked from commit 8018f3bedcb6fb321d1581a47e8c471b31526926)

1 files changed, 7 insertions, 4 deletions

diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_session_cache.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_session_cache.cpp
index 836d42b9e42..3debe9d4a1a 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_session_cache.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_session_cache.cpp
@@ -272,10 +272,13 @@ void WiredTigerSessionCache::releaseSession(WiredTigerSession* session) {
     ON_BLOCK_EXIT([this] { _shuttingDown.fetchAndSubtract(1); });
 
     if (shuttingDown & kShuttingDownMask) {
-        // Leak the session in order to avoid race condition with clean shutdown, where the
-        // storage engine is ripped from underneath transactions, which are not "active"
-        // (i.e., do not have any locks), but are just about to delete the recovery unit.
-        // See SERVER-16031 for more information.
+        // There is a race condition with clean shutdown, where the storage engine is ripped from
+        // underneath OperationContexts, which are not "active" (i.e., do not have any locks), but
+        // are just about to delete the recovery unit. See SERVER-16031 for more information. Since
+        // shutting down the WT_CONNECTION will close all WT_SESSIONS, we shouldn't also try to
+        // directly close this session.
+        session->_session = nullptr;  // Prevents calling _session->close() in destructor.
+        delete session;
         return;
     }