cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Dave Brosius (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-8231) Wrong size of cached prepared statements
Date Wed, 19 Nov 2014 13:34:34 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-8231?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14217900#comment-14217900
] 

Dave Brosius commented on CASSANDRA-8231:
-----------------------------------------

ah one thing. don't forget to change the license file name for jamm.

> Wrong size of cached prepared statements
> ----------------------------------------
>
>                 Key: CASSANDRA-8231
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8231
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>            Reporter: Jaroslav Kamenik
>            Assignee: Benjamin Lerer
>             Fix For: 2.1.3
>
>         Attachments: 8231-notes.txt, CASSANDRA-8231.txt, Unsafes.java
>
>
> Cassandra counts memory footprint of prepared statements for caching purposes. It seems,
that there is problem with some statements, ie SelectStatement. Even simple selects is counted
as 100KB object, updates, deletes etc have few hundreds or thousands bytes. Result is that
cache - QueryProcessor.preparedStatements  - holds just fraction of statements..
> I dig a little into the code, and it seems that problem is in jamm in class MemoryMeter.
It seems that if instance contains reference to class, it counts size of whole class too.
SelectStatement references EnumSet through ResultSet.Metadata and EnumSet holds reference
to Enum class...



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

Mime
View raw message