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https://issues.apache.org/jira/browse/HBASE-11876?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14117885#comment-14117885
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Lars Hofhansl commented on HBASE-11876:
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Let's discuss. The one problem I see that a client (coprocessor) could call
nextRaw(...) cause lots of load on the RS, that would not register as a scan
metric on the RS unless the coprocessor is a good citizen. (of course a called
can already wreak havoc by failing to start/stop the region operation or to
synchronize on the scanner object)
If no objections I'll make a patch.
> RegionScanner.nextRaw(...) should update metrics
> ------------------------------------------------
>
> Key: HBASE-11876
> URL: https://issues.apache.org/jira/browse/HBASE-11876
> Project: HBase
> Issue Type: Bug
> Affects Versions: 0.98.6
> Reporter: Lars Hofhansl
>
> I added the RegionScanner.nextRaw(...) to allow "smart" client to avoid some
> of the default work that HBase is doing, such as {start|stop}RegionOperation
> and synchronized(scanner) for each row.
> Metrics should follow the same approach. Collecting them per row is expensive
> and a caller should have the option to collect those later or to avoid
> collecting them completely.
> We can also save some cycles in RSRcpServices.scan(...) if we updated the
> metric only once/batch instead of each row.
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