db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Kathey Marsden (JIRA)" <j...@apache.org>
Subject [jira] Created: (DERBY-4055) Space may not be reclaimed if locks are not available after three retries (code inspection)
Date Thu, 12 Feb 2009 19:42:59 GMT
Space may not be reclaimed if locks are not available after three retries (code inspection)
-------------------------------------------------------------------------------------------

                 Key: DERBY-4055
                 URL: https://issues.apache.org/jira/browse/DERBY-4055
             Project: Derby
          Issue Type: Bug
          Components: Store
    Affects Versions: 10.4.2.0, 10.3.3.0, 10.2.2.0, 10.1.3.1, 10.5.0.0
            Reporter: Kathey Marsden
            Priority: Minor


I don't have a reproduction for these cases but there are two places in ReclaimSpaceHelper
where reclamation will give up after three tries if it cannot obtain the lock to reclaim the
space.  The first code path is:
ContainerHandle containerHdl = 
			openContainerNW(tran, container_rlock, work.getContainerId());

		if (containerHdl == null)
		{
			tran.abort();

			if (SanityManager.DEBUG)
            {
                if (SanityManager.DEBUG_ON(DaemonService.DaemonTrace))
                {
                    SanityManager.DEBUG(
                        DaemonService.DaemonTrace, " aborted " + work + 
                        " because container is locked or dropped");
                }
            }

			if (work.incrAttempts() < 3) // retry this for serveral times
            {
				return Serviceable.REQUEUE;
            }
			else
            {
                // If code gets here, the space will be lost forever, and
                // can only be reclaimed by a full offline compress of the
                // table/index.

                if (SanityManager.DEBUG)
                {
                    if (SanityManager.DEBUG_ON(DaemonService.DaemonTrace))
                    {
                        SanityManager.DEBUG(
                            DaemonService.DaemonTrace, 
                            "  gave up after 3 tries to get container lock " + 
                            work);
                    }
                }

				return Serviceable.DONE;
            }
		}	

the second is:
	RecordHandle headRecord = work.getHeadRowHandle();

		if (!container_rlock.lockRecordForWrite(
                tran, headRecord, false /* not insert */, false /* nowait */))
		{
			// cannot get the row lock, retry
			tran.abort();
			if (work.incrAttempts() < 3)
            {
				return Serviceable.REQUEUE;
            }
			else
            {
                // If code gets here, the space will be lost forever, and
                // can only be reclaimed by a full offline compress of the
                // table/index.

                if (SanityManager.DEBUG)
                {
                    if (SanityManager.DEBUG_ON(DaemonService.DaemonTrace))
                    {
                        SanityManager.DEBUG(
                            DaemonService.DaemonTrace, 
                            "  gave up after 3 tries to get row lock " + 
                            work);
                    }
                }
				return Serviceable.DONE;
            }
		}

If working to get a reproduction for these cases, you can set derby.debug.true=DaemonTrace
and look for "gave up" in the derby.log.




-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message