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https://issues.apache.org/jira/browse/HBASE-28204?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Mihir Monani updated HBASE-28204:
---------------------------------
Description:
In CanaryTool.java, Canary reads only the first row of the region using
[Get|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L520C33-L520C33]
for any region of the table. Canary uses [Scan with FirstRowKeyFilter for
table
scan|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L530]
If the said region has empty start key (This will only happen when region is
the first region for a table)
With -[HBASE-16091|https://issues.apache.org/jira/browse/HBASE-16091]- RawScan
was
[implemented|https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L519-L534]
to improve performance for regions which can have high number of delete
markers. Based on currently implementation, [RawScan is only
enabled|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L519]
if region has empty start-key (or region is first region for the table).
RawScan doesn't work for rest of the regions in the table except first region.
Also If the region has all the rows or majority of the rows with delete
markers, Get Operation can take a lot of time. This is can cause timeouts for
CanaryTool.
was:
In CanaryTool.java, Canary reads only the first row of the region using
[Get|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L520C33-L520C33]
for any region of the table. Canary uses [Scan with FirstRowKeyFilter for
table
scan|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L530]
If the said region has empty start key (This will only happen when region is
the first region for a table)
With [HBASE-16091|https://issues.apache.org/jira/browse/HBASE-16091] RawScan
was
[implemented|https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L519-L534]
to improve performance for regions which can have high number of delete
markers. Based on currently implementation, [RawScan is only
enabled|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L519]
if region has empty start-key (or region is first region for the table).
RawScan doesn't work for rest of the regions in the table except first region.
Also If the region has all the rows or majority of the rows with delete
markers, Get Operation can take a lot of time. This is can cause timeouts for
CanaryTool.
> Canary can take lot more time If region starts with delete markers
> ------------------------------------------------------------------
>
> Key: HBASE-28204
> URL: https://issues.apache.org/jira/browse/HBASE-28204
> Project: HBase
> Issue Type: Bug
> Components: canary
> Reporter: Mihir Monani
> Assignee: Mihir Monani
> Priority: Major
>
> In CanaryTool.java, Canary reads only the first row of the region using
> [Get|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L520C33-L520C33]
> for any region of the table. Canary uses [Scan with FirstRowKeyFilter for
> table
> scan|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L530]
> If the said region has empty start key (This will only happen when region is
> the first region for a table)
> With -[HBASE-16091|https://issues.apache.org/jira/browse/HBASE-16091]-
> RawScan was
> [implemented|https://github.com/apache/hbase/blob/master/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L519-L534]
> to improve performance for regions which can have high number of delete
> markers. Based on currently implementation, [RawScan is only
> enabled|https://github.com/apache/hbase/blob/23c41560d58cc1353b8a466deacd02dfee9e6743/hbase-server/src/main/java/org/apache/hadoop/hbase/tool/CanaryTool.java#L519]
> if region has empty start-key (or region is first region for the table).
> RawScan doesn't work for rest of the regions in the table except first
> region. Also If the region has all the rows or majority of the rows with
> delete markers, Get Operation can take a lot of time. This is can cause
> timeouts for CanaryTool.
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