@@ -663,6 +663,15 @@ MtmResetTransaction(MtmCurrentTrans* x)
663663x -> status = TRANSACTION_STATUS_UNKNOWN ;
664664}
665665
666+
667+ static const char * const isoLevelStr []=
668+ {
669+ "read uncommitted" ,
670+ "read committed" ,
671+ "repeatable read" ,
672+ "serializable"
673+ };
674+
666675static void
667676MtmBeginTransaction (MtmCurrentTrans * x )
668677{
@@ -679,13 +688,16 @@ MtmBeginTransaction(MtmCurrentTrans* x)
679688x -> isPrepared = false;
680689x -> isTransactionBlock = IsTransactionBlock ();
681690/* Application name can be changed usnig PGAPPNAME environment variable */
682- if (! IsBackgroundWorker && x -> isDistributed && Mtm -> status != MTM_ONLINE && strcmp (application_name ,MULTIMASTER_ADMIN )!= 0 ) {
691+ if (x -> isDistributed && Mtm -> status != MTM_ONLINE && strcmp (application_name ,MULTIMASTER_ADMIN )!= 0 ) {
683692/* Reject all user's transactions at offline cluster.
684693 * Allow execution of transaction by bg-workers to make it possible to perform recovery.
685694 */
686695MtmUnlock ();
687696elog (ERROR ,"Multimaster node is not online: current status %s" ,MtmNodeStatusMnem [Mtm -> status ]);
688697}
698+ if (x -> isDistributed && XactIsoLevel != XACT_REPEATABLE_READ ) {
699+ elog (LOG ,"Isolation level %s is not supported by multimaster" ,isoLevelStr [XactIsoLevel ]);
700+ }
689701x -> containsDML = false;
690702x -> snapshot = MtmAssignCSN ();
691703x -> gtid .xid = InvalidTransactionId ;
@@ -2163,6 +2175,13 @@ _PG_init(void)
21632175NULL
21642176);
21652177
2178+ if (DefaultXactIsoLevel != XACT_REPEATABLE_READ ) {
2179+ elog (ERROR ,"Multimaster requires repeatable read default isolation level" );
2180+ }
2181+ if (synchronous_commit != SYNCHRONOUS_COMMIT_ON ) {
2182+ elog (ERROR ,"Multimaster requires synchronous commit on" );
2183+ }
2184+
21662185MtmSplitConnStrs ();
21672186MtmStartReceivers ();
21682187