apex-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Munagala V. Ramanath (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (APEXCORE-556) New operator attribute - RECOVERY_WINDOW_COUNT
Date Wed, 12 Oct 2016 19:08:21 GMT

    [ https://issues.apache.org/jira/browse/APEXCORE-556?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15569606#comment-15569606
] 

Munagala V. Ramanath commented on APEXCORE-556:
-----------------------------------------------

The `AbstractFileInputOperator` can potentially benefit from this attribute; the scenario
is as follows:
During recovery, `beginWindow()` invokes `replay()` which retrieves files and offsets for
this window
from the `WindowDataManager`, opens the files and reads records starting from the beginning,
discarding them till we reach the offset -- in a tight loop (there is actually a JIRA for
a bug with a
related PR open https://issues.apache.org/jira/browse/APEXMALHAR-2270).
For a large file, this can take many minutes and result in the operator being considered hung
and restarted
causing the same problem all over again.


> New operator attribute - RECOVERY_WINDOW_COUNT
> ----------------------------------------------
>
>                 Key: APEXCORE-556
>                 URL: https://issues.apache.org/jira/browse/APEXCORE-556
>             Project: Apache Apex Core
>          Issue Type: Improvement
>            Reporter: Sandesh
>
> During recovery operators need more time, so it is better to have different per operator
attribute representing that behaviour.
> Note:
> 1. Input and output operators need to have a higher value for this attribute, as that
is where recovery times are higher.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message