Mailing-List: contact issues-help@nifi.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@nifi.apache.org
Date: Tue, 6 Sep 2016 16:24:20 +0000 (UTC)
From: "ASF GitHub Bot (JIRA)" <jira@apache.org>
To: issues@nifi.apache.org
Message-ID: <JIRA.13000544.1472256124000.498832.1473179060679@Atlassian.JIRA>
In-Reply-To: <JIRA.13000544.1472256124000@Atlassian.JIRA>
References: <JIRA.13000544.1472256124000@Atlassian.JIRA> <JIRA.13000544.1472256124450@arcas>
Subject: [jira] [Commented] (NIFI-2681) Avoid caching Provenance Index
 Searchers
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
archived-at: Tue, 06 Sep 2016 16:24:22 -0000


    [ https://issues.apache.org/jira/browse/NIFI-2681?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15467814#comment-15467814 ] 

ASF GitHub Bot commented on NIFI-2681:
--------------------------------------

Github user bbende commented on the issue:

    https://github.com/apache/nifi/pull/958
  
    +1 full build passes and provenance appears to work fine, will merge to master


> Avoid caching Provenance Index Searchers
> ----------------------------------------
>
>                 Key: NIFI-2681
>                 URL: https://issues.apache.org/jira/browse/NIFI-2681
>             Project: Apache NiFi
>          Issue Type: Bug
>          Components: Core Framework
>            Reporter: Mark Payne
>            Assignee: Mark Payne
>            Priority: Critical
>             Fix For: 1.1.0
>
>
> In NIFI-2600 and NIFI-2452, we addressed two bugs where the Provenance Repository closes a cached IndexSearcher too soon. The IndexManager keeps the searchers cached in an effort to offer better performance when performing a Provenance Query. This was done because it was recommended in the Lucene documentation. However, we occasionally still see nodes crashing with segfaults due to the Lucene Searching. We should update the Persistent Provenance Repository to stop caching Index Searchers in order to trade a slight performance improvement for significantly better reliability.
> Playing around with the idea in order to test it out shows very favorable results. On a system where I could cause a seg fault almost every time that I ran a large provenance query, I updated the code to no longer cache the readers and saw perfect stability with no noticeable performance degradation.
> I will cleanup the code and submit a PR for these changes.


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