cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Cristian Opris (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-5062) Support CAS
Date Wed, 27 Feb 2013 13:37:16 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-5062?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13588332#comment-13588332
] 

Cristian Opris commented on CASSANDRA-5062:
-------------------------------------------

Re. which storage to use for metadata, why not use a meta-column family, like for secondary
indexes, or like the locks would have required ? 

For Zab a persistent log will be necessary, and for Paxos a way to persist the paxos round
state for each row.
                
> Support CAS
> -----------
>
>                 Key: CASSANDRA-5062
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-5062
>             Project: Cassandra
>          Issue Type: New Feature
>          Components: API, Core
>            Reporter: Jonathan Ellis
>             Fix For: 2.0
>
>
> "Strong" consistency is not enough to prevent race conditions.  The classic example is
user account creation: we want to ensure usernames are unique, so we only want to signal account
creation success if nobody else has created the account yet.  But naive read-then-write allows
clients to race and both think they have a green light to create.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message