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Date: Tue, 1 Dec 2015 17:05:11 +0000 (UTC)
From: "Suma Shivaprasad (JIRA)" <jira@apache.org>
To: dev@atlas.incubator.apache.org
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Subject: [jira] [Commented] (ATLAS-352) Fix performance issues with type and
 entity creation with Hbase as storage backend
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    [ https://issues.apache.org/jira/browse/ATLAS-352?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15034074#comment-15034074 ] 

Suma Shivaprasad commented on ATLAS-352:
----------------------------------------

On investigating, it was found that Titan holds locks at 2 levels - one at a local level among threads and another  at a global level as a distributed lock among titan instances. The disrtibuted lock is maintained for every KeyColumn that its trying to mutate in Hbase and it ends up doing a lot of writes for locking and lot of reads to check if the current local original values before the mutation began for the keyColumn are matching with the ones during transaction commit. If it doesnt match, the transaction is failed. 

As for Atlas , since it operates only a single instance of Titan currently, the locks can be maintained only at a local level among different threads in the same JVM(Atlas) 

> Fix performance issues with type and entity creation with Hbase as storage backend 
> -----------------------------------------------------------------------------------
>
>                 Key: ATLAS-352
>                 URL: https://issues.apache.org/jira/browse/ATLAS-352
>             Project: Atlas
>          Issue Type: Improvement
>    Affects Versions: 0.6-incubating
>            Reporter: Suma Shivaprasad
>            Assignee: Suma Shivaprasad
>
> Current perf microbenchmark measurements
> DataSet		quickstart model and entity definitions
> No of class types 		6
> traits		6 with no attributes
> server start up time with existing schema	17 secs	
> type batch creation 		27 secs
> entity creation - DB		12 secs
> entity creation - Table		11 secs


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