Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@cassandra.apache.org
Message-ID: <29336639.184161275667374635.JavaMail.jira@thor>
Date: Fri, 4 Jun 2010 12:02:54 -0400 (EDT)
From: "Brandon Williams (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
Subject: [jira] Issue Comment Edited: (CASSANDRA-1142) redesign hinted
 handoff schema
In-Reply-To: <30414339.53941275066165218.JavaMail.jira@thor>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/CASSANDRA-1142?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12875632#action_12875632 ] 

Brandon Williams edited comment on CASSANDRA-1142 at 6/4/10 12:01 PM:
----------------------------------------------------------------------

Patch to change schema as described.  It's possible that a hint will be kept forever with CASSANDRA-1118, but that's easier to address after this patch.

      was (Author: brandon.williams):
    Patch to change schema as described.  A thought, though: perhaps we should either store the token instead of ep, or use a lower value than Integer.MAX_VALUE for gcBefore, since with CASSANDRA-1118 it seems like a hint could be stored for a very long time.
  
> redesign hinted handoff schema
> ------------------------------
>
>                 Key: CASSANDRA-1142
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-1142
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>            Reporter: Jonathan Ellis
>            Assignee: Brandon Williams
>             Fix For: 0.7
>
>         Attachments: 1142.txt
>
>
> Currently, the HH schema looks like this:
>  * For each table (keyspace), there is a row in the system hints CF.
>  * SuperColumns in that row are keys for which we have hinted data.
>  * Subcolumns names within that supercolumn are host IPs. Subcolumn values are always empty.
>  * Instead, we store the row data "normally" in the application table it belongs in.
> This has the drawback that we need to scan the entire hints data set to deliver hints to a given endpoint.  I propose instead we do this:
>  * Row keys are endpoints for which we have hints.
>  * SuperColumns in that row are keys for which we have hinted data.
>  * Subcolumns names within that supercolumn are Keyspace + CF names, joined with a '-' (which is an illegal character in CF names, so it's safe to use here)
> This makes looking up hints for a single endpoint efficient, as well as making it so we only have to read data from CFs for which we actually have data for the key.
> Actual row data continues to be stored in application tables.
> Makes sense to do this after CASSANDRA-1141.

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