hbase-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jingcheng Du (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HBASE-14460) [Perf Regression] Merge of MVCC and SequenceId (HBASE-HBASE-8763) slowed Increments, CheckAndPuts, batch operations
Date Thu, 29 Oct 2015 06:53:27 GMT

    [ https://issues.apache.org/jira/browse/HBASE-14460?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14979933#comment-14979933
] 

Jingcheng Du commented on HBASE-14460:
--------------------------------------

bq. Or maybe these counter types(append, increase, etc.) of cells and the latest put that
is older than counter cells with the same row key can be kept always, maybe the TTL can be
honored for this latest put?
bq. I mean if all the counter cells are only summed up in major compaction, the special column
family is not needed.
Sorry for the misleading words. I mean these counter cells and latest put that is older than
counter cells with the same row key can be kept in minor compaction. In this case, at least
one put (even it is expired) for each key will be kept even if there is not counter cells
for that key in this minor compaction. 
bq. Does it have to be a special counter column family so it easy to treat counters special?
And yes,  a special column family is a better idea to avoid breaking the compaction rules
in normal column families.

> [Perf Regression] Merge of MVCC and SequenceId (HBASE-HBASE-8763) slowed Increments,
CheckAndPuts, batch operations
> -------------------------------------------------------------------------------------------------------------------
>
>                 Key: HBASE-14460
>                 URL: https://issues.apache.org/jira/browse/HBASE-14460
>             Project: HBase
>          Issue Type: Bug
>          Components: Performance
>            Reporter: stack
>            Assignee: stack
>            Priority: Critical
>         Attachments: 14460.txt, region_lock.png
>
>
> As reported by 鈴木俊裕 up on the mailing list -- see "Performance degradation between
CDH5.3.1(HBase0.98.6) and CDH5.4.5(HBase1.0.0)" -- our unification of sequenceid and MVCC
slows Increments (and other ops) as the mvcc needs to 'catch up' to our current point before
we can read the last Increment value that we need to update.
> We can say that our Increment is just done wrong, we should just be writing Increments
and summing on read, but checkAndPut as well as batching operations have the same issue. Fix.



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

Mime
View raw message