SERVER-31367 Ignore _getNextSessionMods CommandNotFound errors

1 files changed, 7 insertions, 0 deletions

diff --git a/src/mongo/db/s/session_catalog_migration_destination.cpp b/src/mongo/db/s/session_catalog_migration_destination.cpp
index b1b373f17c5..6f6865d5f15 100644
--- a/src/mongo/db/s/session_catalog_migration_destination.cpp
+++ b/src/mongo/db/s/session_catalog_migration_destination.cpp
@@ -428,6 +428,13 @@ void SessionCatalogMigrationDestination::_retrieveSessionStateFromSource(Service
                 continue;
             }
 
+            if (excep.code() == ErrorCodes::CommandNotFound) {
+                // TODO: remove this after v3.7.
+                // This means that the donor shard is running at an older version so it is safe
+                // to just end this because there is no session information to transfer.
+                break;
+            }
+
             _errorOccurred(excep.toString());
             return;
         }