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https://issues.apache.org/jira/browse/HBASE-14055?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14623096#comment-14623096
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Enis Soztutar commented on HBASE-14055:
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Thanks Stack for taking a look.
bq. What is requestSystemCompaction?
It comes from CompactSplitThread. Seems that the only difference is priority.
There are callers which used to call
CompactSplitTread.requestSystemCompaction(). Did not check why this versus the
one with explicit priority.
bq. How much of this patch comes from the region-as-pv2-store experiment, if
any?
Almost all of this patch is a subset of region-as-pv2-store experiment (parent
jira).
bq. What is going on with this change where compactions and memstore checker
are no longer ScheduledChores?
bq. Does this undo work reducing running chore thread count?
Good question. It is not changing these compaction and flusher threads for now.
They are still executed by the chore service of HRS. The WAL threads WALRoller
has been moved to be inside WALContainer, but WALRoller was not a chore service
anyway.
There should be a follow up to this this which continues with the separation.
HRegion still gets a reference to {{RegionServerServices}} rather than
{{RegionServices}} and flusher / compaction is still owned by the RS.
bq. When would RegionServices change out from under us? Or is this just around
starting and stopping so RegionServices not pulled from under running chores?
HRS.addRegionServices() is for adding new RegionServices (if you have). Right
now only customer for that API was EmbeddedDatabase from parent patch. But I
think we can keep it around for the follow up cleaning.
> Untangle region - region server dependencies
> --------------------------------------------
>
> Key: HBASE-14055
> URL: https://issues.apache.org/jira/browse/HBASE-14055
> Project: HBase
> Issue Type: Sub-task
> Reporter: Enis Soztutar
> Assignee: Enis Soztutar
> Fix For: 2.0.0, 1.3.0
>
> Attachments: hbase-14055_v1.patch
>
>
> We need to untangle region from outside of region server. The parent jira is
> trying to create an embedded library, like leveldb, out of region so that it
> should be possible to host a set of regions without being a regionserver.
> From a layering point of view, region hosting and WAL services should be
> abstracted. Hosting a region means threads for flushing, compaction,
> cleanups, hosting a WAL, and block cache. The RegionServer normally holds
> these, together with RpcServer and zk connection, heartbeats, and all other
> stuff that is required for running as a deamon and inside a cluster.
> See parent jira for some more context.
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