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From "James Taylor (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (PHOENIX-2221) Option to make data regions not writable when index regions are not available
Date Mon, 28 Dec 2015 00:52:49 GMT

    [ https://issues.apache.org/jira/browse/PHOENIX-2221?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15072306#comment-15072306
] 

James Taylor commented on PHOENIX-2221:
---------------------------------------

[~ayingshu] - we plan to do the 4.7.0 as soon as we can in January - just waiting for a few
straggler issues to come in.

The way you'd do this is by caching INDEX_DISABLE_TIMESTAMP in a member variable in PTable
with a new getter for it in the interface. The value is already written to the table header
row, so you'd just need to read the value in MetaDataEndpointImpl:
{code}
    private PTable getTable(RegionScanner scanner, long clientTimeStamp, long tableTimeStamp)
{code}
and pass it through the {{PTableImpl.makePTable()}} call toward the end of that method.

The mechanism is already in place for the PTable to make it's way over to the client side,
so then you'd just be using the new {{PTable.getIndexDisableTimestamp()}} method you add.

> Option to make data regions not writable when index regions are not available
> -----------------------------------------------------------------------------
>
>                 Key: PHOENIX-2221
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-2221
>             Project: Phoenix
>          Issue Type: Improvement
>            Reporter: Devaraj Das
>            Assignee: Alicia Ying Shu
>             Fix For: 4.7.0
>
>         Attachments: PHOENIX-2221-v1.patch, PHOENIX-2221-v2.patch, PHOENIX-2221-v3.patch,
PHOENIX-2221.patch
>
>
> In one usecase, it was deemed better to not accept writes when the index regions are
unavailable for any reason (as opposed to disabling the index and the queries doing bigger
data-table scans).
> The idea is that the index regions are kept consistent with the data regions, and when
a query runs against the index regions, one can be reasonably sure that the query ran with
the most recent data in the data regions. When the index regions are unavailable, the writes
to the data table are rejected. Read queries off of the index regions would have deterministic
performance (and on the other hand if the index is disabled, then the read queries would have
to go to the data regions until the indexes are rebuilt, and the queries would suffer).



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