You are viewing a plain text version of this content. The canonical link for it is here.
Posted to dev@lucene.apache.org by "Tommaso Teofili (JIRA)" <ji...@apache.org> on 2018/05/28 07:38:00 UTC

[jira] [Updated] (LUCENE-8162) Make it possible to throttle (Tiered)MergePolicy when commit rate is high

     [ https://issues.apache.org/jira/browse/LUCENE-8162?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Tommaso Teofili updated LUCENE-8162:
------------------------------------
    Attachment: LUCENE-8162.0.patch

> Make it possible to throttle (Tiered)MergePolicy when commit rate is high
> -------------------------------------------------------------------------
>
>                 Key: LUCENE-8162
>                 URL: https://issues.apache.org/jira/browse/LUCENE-8162
>             Project: Lucene - Core
>          Issue Type: Improvement
>          Components: core/index
>            Reporter: Tommaso Teofili
>            Priority: Major
>             Fix For: trunk
>
>         Attachments: LUCENE-8162.0.patch
>
>
> As discussed in a recent mailing list thread [1] and observed in a project using Lucene (see OAK-5192 and OAK-6710), it is sometimes helpful to throttle the aggressiveness of (Tiered)MergePolicy when commit rate is high.
> In the case of Apache Jackrabbit Oak a dedicated {{MergePolicy}} was implemented [2].
> That MP doesn't merge in case the number of segments is below a certain threshold (e.g. 30) and commit rate (docs per sec and MB per sec) is high (e.g. above 1000 doc / sec , 5MB / sec).
> In such impl, the commit rate thresholds adapt to average commit rate by means of single exponential smoothing.
> The results in that specific case looked encouraging as it brought a 5% perf improvement in querying and ~10% reduced IO. However Oak has some specifics which might not fit in other scenarios. Anyway it could be interesting to see how this behaves in plain Lucene scenario.
> [1] : [http://markmail.org/message/re3ifmq2664bqfjk]
> [2] : [https://github.com/apache/jackrabbit-oak/blob/trunk/oak-lucene/src/main/java/org/apache/jackrabbit/oak/plugins/index/lucene/writer/CommitMitigatingTieredMergePolicy.java]



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org