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https://issues.apache.org/jira/browse/TRAFODION-1996?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Sean Broeder updated TRAFODION-1996:
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Description: When deleting old entries in the TLOG tables a complete table
scan is performed and all regions for all TLOG tables are scanned in parallel.
This was done to try to improve performance by attempting to delete all old
entries as quickly as possible. However, with extremely large scans on busy
systems the scans can become quite large and in a worst case scenario can
starve out other requests in a regions server by dominating the handlers and
potentially causing a RS failure due to a long GC pause. (was: When deleting
old entries in the TLOG tables a complete table scan is performed and a list of
deletes is accumulated. This was done to try to improve performance by
attempting to delete all old entries in a single list of deletes. However,
with extremely large scans the list of deletes can become quite large and in a
worst case scenario if a RS failure occurs due to a long GC we would need to
scan the entire table again and possibly cause another RS failure due to a long
GC pause.)
> TLOG uses excessive memory when aging old entries
> -------------------------------------------------
>
> Key: TRAFODION-1996
> URL: https://issues.apache.org/jira/browse/TRAFODION-1996
> Project: Apache Trafodion
> Issue Type: Bug
> Components: dtm
> Affects Versions: 2.0-incubating
> Reporter: Sean Broeder
> Assignee: Sean Broeder
> Fix For: 2.1-incubating
>
> Original Estimate: 168h
> Remaining Estimate: 168h
>
> When deleting old entries in the TLOG tables a complete table scan is
> performed and all regions for all TLOG tables are scanned in parallel. This
> was done to try to improve performance by attempting to delete all old
> entries as quickly as possible. However, with extremely large scans on busy
> systems the scans can become quite large and in a worst case scenario can
> starve out other requests in a regions server by dominating the handlers and
> potentially causing a RS failure due to a long GC pause.
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