[
https://issues.apache.org/jira/browse/ACCUMULO-3510?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14289991#comment-14289991
]
Christopher Tubbs commented on ACCUMULO-3510:
---------------------------------------------
I look forward to examining the patch. Since it adds functionality, we cannot
apply to a patch/bugfix release, so please ensure your patch applies cleanly on
the master branch. Also, if you are currently working on this patch, please
mark this issue as "In Progress" by clicking the "Start Progress" button above,
so we know you're working on it. Thanks!
> Create mechanism to support priority based scheduling of read ahead tasks.
> ---------------------------------------------------------------------------
>
> Key: ACCUMULO-3510
> URL: https://issues.apache.org/jira/browse/ACCUMULO-3510
> Project: Accumulo
> Issue Type: Improvement
> Components: tserver
> Affects Versions: 1.6.0
> Reporter: marco polo
> Assignee: marco polo
> Priority: Minor
> Fix For: 1.7.0
>
>
> I have many cases where ScanSessions will consume resources that I otherwise
> want shorter running scans to utilize. In some cases, a scan may continue for
> hours, while a short running scan may come in and execute quickly. As a
> result, I want to be able to adjust the priority of these scan sessions.
> I have a patch which is forthcoming, that breaks Session out of TabletServer
> and replaces the queue in the readAheadThreadPool with a priority pool. The
> comparator I have created as a proof of concept, which can be adjustable,
> reduces the priority of the oldest scan. Using an aging technique, we
> guarantee execute of these older running scans based upon the previous run
> time. As a result, we give preference to newer scans. If they execute
> quickly, older scans will have an inherent rise in priority. If they also
> take a while, their priority will be reduced and incoming scans will yet
> again be given a greater priority with the intent (and/or hope ) their
> execution will be faster.
> Priority should be configurable based on the desired Session Comparator.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
