[ 
https://issues.apache.org/jira/browse/CASSANDRA-5704?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13693997#comment-13693997
 ] 

Brandon Williams commented on CASSANDRA-5704:
---------------------------------------------

bq. "Data that was supposed to be gone, could reappear" which feels 
semantically different to me.

I tend to agree.  Certainly if the biggest problem here is tests are slow, it's 
not worth the risk just to speed them up.  We could do something like add a 
flag if we need this.
                
> Truncate flushes to disk again in 1.2, even with durable_writes=false
> ---------------------------------------------------------------------
>
>                 Key: CASSANDRA-5704
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-5704
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Core
>    Affects Versions: 1.2.5
>            Reporter: Christian Spriegel
>            Assignee: Christian Spriegel
>            Priority: Minor
>             Fix For: 1.2.7
>
>         Attachments: CASSANDRA_5704_V1_1_2.patch, 
> CASSANDRA_5704_V1_trunk.patch
>
>
> I just upgraded my dev-environment to C* 1.2. Unfortunetaly 1.2 makes my 
> JUnit tests slow again, due to a blocking-flush in saveTruncationRecord().
> With Cassandra 1.1 truncate was very fast due to: CASSANDRA-4153
> My proposal is to make saveTruncationRecord() only flush when durableWrites 
> are enabled.
> My assumption is that if somebody turn off durable writes then he does not 
> mind if truncate is not guaranteed to be durable either.
> I successfully tested the following patch with my testsuite. Its as fast as 
> it was with 1.1 (maybe even faster!):
> {code}
> @@ -186,5 +186,8 @@ public class SystemTable
>          String req = "UPDATE system.%s SET truncated_at = truncated_at + %s 
> WHERE key = '%s'";
>          processInternal(String.format(req, LOCAL_CF, 
> truncationAsMapEntry(cfs, truncatedAt, position), LOCAL_KEY));
> -        forceBlockingFlush(LOCAL_CF);
> +        
> +        KSMetaData ksm = Schema.instance.getKSMetaData(cfs.table.name);
> +        if (ksm.durableWrites) // flush only when durable_writes are enabled
> +            forceBlockingFlush(LOCAL_CF);
>      }
> {code}

--
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

Reply via email to