[JBoss JIRA] (TEIID-5422) Buffer cleaner running too often in some cases
by Steven Hawkins (JIRA)
[ https://issues.jboss.org/browse/TEIID-5422?page=com.atlassian.jira.plugin... ]
Steven Hawkins resolved TEIID-5422.
-----------------------------------
Resolution: Done
Changed the interval to 5 seconds (more than twice the default timeslice of 2 seconds) which shows a great improvement in the performance test checked in with this issue, but no degradation in the other performance tests.
> Buffer cleaner running too often in some cases
> ----------------------------------------------
>
> Key: TEIID-5422
> URL: https://issues.jboss.org/browse/TEIID-5422
> Project: Teiid
> Issue Type: Bug
> Components: Query Engine
> Reporter: Steven Hawkins
> Assignee: Steven Hawkins
> Fix For: 11.1, 11.0.1, 10.3.3
>
>
> As observed in TEIID-5418 when the buffer cleaner runs too often it causes thrashing by pushing out pages that get reused close to the cleaning interval of 100 milliseconds.
> Increasing that interval to at least beyond the default time-slice will consume more heap - but the cleaner will still be engaged when a processing thread must clean beyond the max allowed.
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[JBoss JIRA] (TEIID-5422) Buffer cleaner running too often in some cases
by Steven Hawkins (JIRA)
Steven Hawkins created TEIID-5422:
-------------------------------------
Summary: Buffer cleaner running too often in some cases
Key: TEIID-5422
URL: https://issues.jboss.org/browse/TEIID-5422
Project: Teiid
Issue Type: Bug
Components: Query Engine
Reporter: Steven Hawkins
Assignee: Steven Hawkins
Fix For: 11.1, 11.0.1, 10.3.3
As observed in TEIID-5418 when the buffer cleaner runs too often it causes thrashing by pushing out pages that get reused close to the cleaning interval of 100 milliseconds.
Increasing that interval to at least beyond the default time-slice will consume more heap - but the cleaner will still be engaged when a processing thread must clean beyond the max allowed.
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[JBoss JIRA] (TEIID-5420) Costing can over estimate join cardinality when no keys nor ndv is specified
by Steven Hawkins (JIRA)
[ https://issues.jboss.org/browse/TEIID-5420?page=com.atlassian.jira.plugin... ]
Steven Hawkins updated TEIID-5420:
----------------------------------
Description: The changes from TEIID-4885 allow for joins lacking all but cardinality information to have their cardinality over-estimated. The estimate should be made more cautious by default as that would be the most common case. (was: The changes from TEIID-4485 allow for joins lacking all but cardinality information to have their cardinality over-estimated. The estimate should be made more cautious by default as that would be the most common case.)
> Costing can over estimate join cardinality when no keys nor ndv is specified
> ----------------------------------------------------------------------------
>
> Key: TEIID-5420
> URL: https://issues.jboss.org/browse/TEIID-5420
> Project: Teiid
> Issue Type: Quality Risk
> Components: Query Engine
> Reporter: Steven Hawkins
> Assignee: Steven Hawkins
> Fix For: 11.1, 11.0.1
>
>
> The changes from TEIID-4885 allow for joins lacking all but cardinality information to have their cardinality over-estimated. The estimate should be made more cautious by default as that would be the most common case.
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[JBoss JIRA] (TEIID-5421) Regression with enhanced sort join performance
by Steven Hawkins (JIRA)
[ https://issues.jboss.org/browse/TEIID-5421?page=com.atlassian.jira.plugin... ]
Steven Hawkins commented on TEIID-5421:
---------------------------------------
I'm seeing two related issues. The first is that TEIID-5017 allows for some joins to be processed sub-optimally - the avoidance of buffering is causing more work by searching an index that is too large. A follow on issue that is probably not directly related is that running a reproducer for the case described by TEIID-5417 repeatedly shows that as more of the materialization is pushed out of the heap memory space performance significantly drops.
> Regression with enhanced sort join performance
> ----------------------------------------------
>
> Key: TEIID-5421
> URL: https://issues.jboss.org/browse/TEIID-5421
> Project: Teiid
> Issue Type: Bug
> Components: Query Engine
> Affects Versions: 9.3
> Reporter: Steven Hawkins
> Assignee: Steven Hawkins
> Fix For: 11.1
>
>
> A regression was introduced in 9.3 with enhanced sort join performance over moderately large row sets.
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[JBoss JIRA] (TEIID-5421) Regression with enhanced sort join performance
by Steven Hawkins (JIRA)
[ https://issues.jboss.org/browse/TEIID-5421?page=com.atlassian.jira.plugin... ]
Steven Hawkins edited comment on TEIID-5421 at 7/17/18 2:04 PM:
----------------------------------------------------------------
I'm seeing two issues. The first is that TEIID-5017 allows for some joins to be processed sub-optimally - the avoidance of buffering is causing more work by searching an index that is too large. A follow on issue that is probably not directly related is that running a reproducer for the case described by TEIID-5417 repeatedly shows that as more of the materialization is pushed out of the heap memory space performance significantly drops.
was (Author: shawkins):
I'm seeing two related issues. The first is that TEIID-5017 allows for some joins to be processed sub-optimally - the avoidance of buffering is causing more work by searching an index that is too large. A follow on issue that is probably not directly related is that running a reproducer for the case described by TEIID-5417 repeatedly shows that as more of the materialization is pushed out of the heap memory space performance significantly drops.
> Regression with enhanced sort join performance
> ----------------------------------------------
>
> Key: TEIID-5421
> URL: https://issues.jboss.org/browse/TEIID-5421
> Project: Teiid
> Issue Type: Bug
> Components: Query Engine
> Affects Versions: 9.3
> Reporter: Steven Hawkins
> Assignee: Steven Hawkins
> Fix For: 11.1
>
>
> A regression was introduced in 9.3 with enhanced sort join performance over moderately large row sets.
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[JBoss JIRA] (TEIID-5421) Regression with enhanced sort join performance
by Steven Hawkins (JIRA)
Steven Hawkins created TEIID-5421:
-------------------------------------
Summary: Regression with enhanced sort join performance
Key: TEIID-5421
URL: https://issues.jboss.org/browse/TEIID-5421
Project: Teiid
Issue Type: Bug
Components: Query Engine
Affects Versions: 9.3
Reporter: Steven Hawkins
Assignee: Steven Hawkins
Fix For: 11.1
A regression was introduced in 9.3 with enhanced sort join performance over moderately large row sets.
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