cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jonathan Ellis (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-2006) Serverwide caps on memtable thresholds
Date Tue, 05 Apr 2011 13:14:05 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-2006?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13015909#comment-13015909
] 

Jonathan Ellis commented on CASSANDRA-2006:
-------------------------------------------

The count can take minutes, on a large (GB) memtable under load. We probably don't want to
block flush that long.

> Serverwide caps on memtable thresholds
> --------------------------------------
>
>                 Key: CASSANDRA-2006
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-2006
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Stu Hood
>             Fix For: 0.8
>
>         Attachments: 2006-v2.txt, 2006.txt, jamm-0.2.jar
>
>
> By storing global operation and throughput thresholds, we could eliminate the "many small
memtables" problem caused by having many CFs. The global threshold would be set in the config
file, to allow different classes of servers to have different values configured.
> Operations occurring in the memtable would add to the global counters, in addition to
the memtable-local counters. When a global threshold was violated, the memtable in the system
that was using the largest fraction of it's local threshold would be flushed. Local thresholds
would continue to act as they always have.
> The result would be larger sstables, safer operation with multiple CFs and per node tuning.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message