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https://issues.apache.org/jira/browse/CONNECTORS-1746?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Mingchun Zhao updated CONNECTORS-1746:
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Description:
Sometimes, the crawling does not process any documents for a while and there is
nothing logged about long-running queries. The performance can be restored by
firing the 'ANALYZE' command manually. It seems that a bad query plan caused
this performance problem.
Therefore, in addition to the current configuration parameter
'org.apache.manifoldcf.db.postgres.analyze.<tablename>', it is considered
necessary to execute the 'ANALYZE' even in the following situations.
1. When the number of records in the table exceeds the number required for
creating a execution plan after the job starts.
2. When the crawling performance slows down. For example, if the processing
rate of documents drops below a specified threshold.
was:
Sometimes, the crawling does not process any documents for a while and there is
nothing logged about long-running queries. The performance can be restored by
firing the 'ANALYZE' command manually. It seems that a bad query plan caused
this performance problem.
Therefore, in addition to the current configuration parameter
'org.apache.manifoldcf.db.postgres.analyze.<tablename>', it is considered
necessary to execute the 'ANALYZE' even in the following situations.
1. When the number of records in the table exceeds the number required for
creating a execution plan after the job starts.
2. When the crawling performance slows down. For example, if the processing
rate of documents drops below a specified threshold.
So, how about adding two parameters to handle the timing of 'ANALYZE' execution
as below?
1.'org.apache.manifoldcf.db.postgres.analyze.<tablename>.minimumrowcount'
Specify how many records should be inserted before carrying out an 'ANALYZE' on
the specified table as the first time.defaults to 100.
2.'org.apache.manifoldcf.db.postgres.analyze.<tablename>.minimumprocessrate'
Specify the minimum number of documents processed per minute. If the processing
rate of documents drops below this threshold, the 'ANALYZE' will be executed.
defaults to 1.
> Adding conditions to execute PostgreSQL's ANALYZE command to avoid crawling
> become extremely slow.
> --------------------------------------------------------------------------------------------------
>
> Key: CONNECTORS-1746
> URL: https://issues.apache.org/jira/browse/CONNECTORS-1746
> Project: ManifoldCF
> Issue Type: Improvement
> Components: Web connector
> Environment: Using ManifoldCF 2.24 with PostgreSQL 12.14 as the
> database.
> Reporter: Mingchun Zhao
> Priority: Major
>
> Sometimes, the crawling does not process any documents for a while and there
> is nothing logged about long-running queries. The performance can be restored
> by firing the 'ANALYZE' command manually. It seems that a bad query plan
> caused this performance problem.
> Therefore, in addition to the current configuration parameter
> 'org.apache.manifoldcf.db.postgres.analyze.<tablename>', it is considered
> necessary to execute the 'ANALYZE' even in the following situations.
> 1. When the number of records in the table exceeds the number required for
> creating a execution plan after the job starts.
> 2. When the crawling performance slows down. For example, if the processing
> rate of documents drops below a specified threshold.
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