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https://issues.apache.org/jira/browse/HBASE-5162?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14250488#comment-14250488
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Ted Yu commented on HBASE-5162:
-------------------------------
Planning to commit the addendum soon - this JIRA is in 1.0 whose RC is coming
out today.
> Basic client pushback mechanism
> -------------------------------
>
> Key: HBASE-5162
> URL: https://issues.apache.org/jira/browse/HBASE-5162
> Project: HBase
> Issue Type: New Feature
> Affects Versions: 0.92.0
> Reporter: Jean-Daniel Cryans
> Assignee: Jesse Yates
> Fix For: 1.0.0, 2.0.0
>
> Attachments: 5162-addendum2.txt, hbase-5162-branch-1-v0.patch,
> hbase-5162-trunk-addendum.patch, hbase-5162-trunk-v0.patch,
> hbase-5162-trunk-v1.patch, hbase-5162-trunk-v10.patch,
> hbase-5162-trunk-v11.patch, hbase-5162-trunk-v12-committed.patch,
> hbase-5162-trunk-v2.patch, hbase-5162-trunk-v3.patch,
> hbase-5162-trunk-v4.patch, hbase-5162-trunk-v5.patch,
> hbase-5162-trunk-v6.patch, hbase-5162-trunk-v7.patch,
> hbase-5162-trunk-v8.patch, java_HBASE-5162.patch
>
>
> The current blocking we do when we are close to some limits (memstores over
> the multiplier factor, too many store files, global memstore memory) is bad,
> too coarse and confusing. After hitting HBASE-5161, it really becomes obvious
> that we need something better.
> I did a little brainstorm with Stack, we came up quickly with two solutions:
> - Send some exception to the client, like OverloadedException, that's thrown
> when some situation happens like getting past the low memory barrier. It
> would be thrown when the client gets a handler and does some check while
> putting or deleting. The client would treat this a retryable exception but
> ideally wouldn't check .META. for a new location. It could be fancy and have
> multiple levels of pushback, like send the exception to 25% of the clients,
> and then go up if the situation persists. Should be "easy" to implement but
> we'll be using a lot more IO to send the payload over and over again (but at
> least it wouldn't sit in the RS's memory).
> - Send a message alongside a successful put or delete to tell the client to
> slow down a little, this way we don't have to do back and forth with the
> payload between the client and the server. It's a cleaner (I think) but more
> involved solution.
> In every case the RS should do very obvious things to notify the operators of
> this situation, through logs, web UI, metrics, etc.
> Other ideas?
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