Mailing-List: contact cassandra-commits-help@incubator.apache.org;
 run by ezmlm
Precedence: bulk
Reply-To: cassandra-dev@incubator.apache.org
Message-ID: <866074198.1247804234834.JavaMail.jira@brutus>
Date: Thu, 16 Jul 2009 21:17:14 -0700 (PDT)
From: "Michael Greene (JIRA)" <jira@apache.org>
To: cassandra-commits@incubator.apache.org
Subject: [jira] Commented: (CASSANDRA-279) finish snapshot support
In-Reply-To: <59838885.1246914794804.JavaMail.jira@brutus>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/CASSANDRA-279?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12732332#action_12732332 ] 

Michael Greene commented on CASSANDRA-279:
------------------------------------------

I'm definitely going to need this to play nicely with Windows (if not support, then at least fail gracefully) and can test (or write before committed) the functionality if Sammy can't.

What's the intended use of these snapshots?  Restoration at a later date?  Is that scoped to Cassandra or nodeprobe, or would that be a manual process?

> finish snapshot support
> -----------------------
>
>                 Key: CASSANDRA-279
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-279
>             Project: Cassandra
>          Issue Type: New Feature
>          Components: Core
>            Reporter: Jonathan Ellis
>            Assignee: Sammy Yu
>         Attachments: 0001-Work-for-CASSANDRA-279.patch
>
>
> searching for "snapshot" in *.java shows a bunch of code for supporting snapshots via hard links.
> (this works b/c SSTables are immutable, once created.)
> this used to be more complete but when we dropped the JDK7 requirement we just removed the code that we couldn't do in JDK6 and hard link support was one of those.
> So what you would need to do here is:
>  * create a hard link method (using Runtime.exec("ln") on linux / os x I imagine)
>  * add a JMX hook to invoke this on the data files (this is where looking at the old codebase might help); ColumnFamilyStoreMBean.forceFlush is an example of an "Action" jmx interface. using jconsole to interact with JMX stuff is explained here: http://wiki.apache.org/cassandra/MemtableThresholds
>  * add something to list the snapshots available via JMX
>  * optionally make this all per-Table instead of per-database

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.