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https://issues.apache.org/jira/browse/HBASE-19646?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16304677#comment-16304677
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BELUGA BEHR commented on HBASE-19646:
-------------------------------------
Yes, cron tab can be used to launch compaction externally, but then why have
any kind of scheduling included in HBase?
> Add CRON To Major Compaction
> ----------------------------
>
> Key: HBASE-19646
> URL: https://issues.apache.org/jira/browse/HBASE-19646
> Project: HBase
> Issue Type: Bug
> Components: Compaction
> Reporter: BELUGA BEHR
> Priority: Minor
>
> HBase provides _hbase.hregion.majorcompaction_
> {quote}
> Time between major compactions, expressed in milliseconds. Set to 0 to
> disable time-based automatic major compactions. User-requested and size-based
> major compactions will still run. This value is multiplied by
> hbase.hregion.majorcompaction.jitter to cause compaction to start at a
> somewhat-random time during a given window of time. The default value is 7
> days, expressed in milliseconds. If major compactions are causing disruption
> in your environment, you can configure them to run at off-peak times for your
> deployment, or disable time-based major compactions by setting this parameter
> to 0, and run major compactions in a cron job or by another external
> mechanism.
> {quote}
> Instead of this existing mechanism, that adds randomness into a production
> system (ugh), let's simply allow users to specify a cron string and replace
> this simple periodic (+jitter) scheduling mechanism. CRON is useful for
> systems that have known windows of time (i.e. weekend, nights) that are known
> to be good times for compaction.
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