http://www.slony.info/bugzilla/show_bug.cgi?id=258

           Summary: cleanup thread can block waiting on a lock
           Product: Slony-I
           Version: devel
          Platform: PC
        OS/Version: Linux
            Status: NEW
          Severity: enhancement
          Priority: low
         Component: stored procedures
        AssignedTo: slony1-bugs at lists.slony.info
        ReportedBy: ssinger at ca.afilias.info
                CC: slony1-bugs at lists.slony.info
   Estimated Hours: 0.0


We have observed cases where the cleanupThread will block waiting on a lock
before truncating sl_log_1 (or sl_log_2).  While the cleanup thread is waiting
no slon remoteHelper threads are able to query the sl_log tables.

Try the following

T1: begin;
T1: select * FROM _test.sl_log_1;
T2: begin;
T2; lock table _test.sl_log_1 in exclusive mode nowait;
T2: truncate _test.sl_log_1;

T2 blocks on the truncate even though it got the exclusive lock.

If we change the 'lock table' to get an access exclusive lock then it will fail
due to the nowait.

I propose we modify the cleanup function to do this.
Patch to be atttached.

-- 
Configure bugmail: http://www.slony.info/bugzilla/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.
You are the assignee for the bug.