hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Francis Liu (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-15156) Support first assignment of split daughters to non-parent RS
Date Thu, 04 Feb 2016 01:30:39 GMT

    [ https://issues.apache.org/jira/browse/HBASE-15156?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15131515#comment-15131515

Francis Liu commented on HBASE-15156:

Yup it's a small change from the current patch I have. If you see there's only one branch
for the shouldAssign flag and the code is insignificant. I know all too well how fragile the
AM is. This approach simplifies the state machine. For one thing it simplifies the state handling
between splits and SSH (AKA CRP), since it removes that not so nice nuance of having to pretend
that the region server is holding the daughters during PONR, while the other metadata in regionstates
says otherwise.

> Support first assignment of split daughters to non-parent RS
> ------------------------------------------------------------
>                 Key: HBASE-15156
>                 URL: https://issues.apache.org/jira/browse/HBASE-15156
>             Project: HBase
>          Issue Type: New Feature
>            Reporter: Francis Liu
>            Assignee: Francis Liu
>         Attachments: HBASE-15156.patch, HBASE-15156_1.patch
> On region split, the region's daughter is always opened by the same region server hosting
the parent region. In some cases this is not ideal:
> This feature was mainly needed for favored nodes to allow for more freedom when selecting
favored nodes for daughter regions. ie The daughter doesn't have to always select the regionserver
hosting the split as a favored node which should allow for better favored node distribution.
> Though this feature is actually useful in cases where region splits occur much more often
than the balancer is run. It also is a bit more efficient as the major compaction that occurs
after daughter assignment does not go to waste (ie cancelled half-way, loss of locality due
to move, etc). We actually run it this way in some of our clusters even without favored nodes
enabled. Hence I am supplying a patch which is independent of favored nodes.

This message was sent by Atlassian JIRA

View raw message