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https://issues.apache.org/jira/browse/HBASE-16961?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15988733#comment-15988733
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Josh Elser commented on HBASE-16961:
------------------------------------

Sorry, for the delayed reply and thanks for taking a look [~apurtell].

bq. 1. About the optional MasterObserver for automatically deleting quotas when 
the table is deleted. Why do we not want this in general? Make it a part of 
core master, optionally disabled?

Mostly, this came in later; I think that's why I optionally enabled it. I don't 
have a good reason that it should be disable by default.

bq. 2. Under what circumstances is NO_WRITES_COMPACTIONS advisable instead of 
NO_WRITES? 

It comes down to how strict administrators want to be with disk usage. As we 
move towards a reality where space use is closely tracked, we might also want 
to avoid temporary spikes in space usage for the compaction's file set (e.g. a 
compaction of three files, we start out with space use of those three files, 
but then create a new file which would be similar in size. So, we'd actually 
have ~2x the space taken, until the original 3 files are removed).

bq. 3. How would quotas and system recovery actions interact? Are quota checks 
bypassed for actions taken by a superuser?

I actually haven't spent much time investigating this. I'm not sure if I've 
added short-circuits for hbase.superusers. Did you have some specific commands 
in mind WRT "system recovery actions"? I could probably whip up a unit test 
without much hassle.

bq. Yes, this could be a problem, if we are trying to apply quotas to more than 
one table as part of activity to bring something runaway under control. Not 
urgent, but let's make sure there's a follow up JIRA for this. 

Will create and link here.

> FileSystem Quotas
> -----------------
>
>                 Key: HBASE-16961
>                 URL: https://issues.apache.org/jira/browse/HBASE-16961
>             Project: HBase
>          Issue Type: New Feature
>            Reporter: Josh Elser
>            Assignee: Josh Elser
>         Attachments: hbase-quota-test.sh
>
>
> Umbrella issue for tracking the filesystem utilization of HBase data, 
> defining quotas on that utilization, and enforcement when utilization exceeds 
> the limits of the quota.
> At a high level: we can define quotas on tables and namespaces. Region size 
> is computed by RegionServers and sent to the Master. The Master inspects the 
> sizes of Regions, rolling up to table and namespace sizes. Defined quotas in 
> the quota table are evaluated given the computed sizes, and, for those 
> tables/namespaces violating the quota, RegionServers are informed to take 
> some action to limit any further filesystem growth by that table/namespace.
> Discuss: 
> https://lists.apache.org/thread.html/66a4b0c3725b5cbdd61dd6111c43847adaeef7b7da5f4cd045df30ef@%3Cdev.hbase.apache.org%3E
> Design Doc: 
> http://home.apache.org/~elserj/hbase/FileSystemQuotasforApacheHBase.pdf or 
> https://docs.google.com/document/d/1VtLWDkB2tpwc_zgCNPE1ulZOeecF-YA2FYSK3TSs_bw/edit?usp=sharing



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