[jira] [Commented] (CASSANDRA-4718) More-efficient ExecutorService for improved throughput

2013-10-07 Thread darion yaphets (JIRA)

[ 
https://issues.apache.org/jira/browse/CASSANDRA-4718?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13788243#comment-13788243
 ] 

darion yaphets commented on CASSANDRA-4718:
---

LMAX Disruptor's RingBuffer maybe a good idea for lock free component
But maybe set a bigger size for hold the structure in ring buffer to avoid  
cover by new one
And is meaning to use more memory ...

> More-efficient ExecutorService for improved throughput
> --
>
> Key: CASSANDRA-4718
> URL: https://issues.apache.org/jira/browse/CASSANDRA-4718
> Project: Cassandra
>  Issue Type: Improvement
>Reporter: Jonathan Ellis
>Assignee: Jason Brown
>Priority: Minor
>  Labels: performance
> Attachments: baq vs trunk.png, op costs of various queues.ods, 
> PerThreadQueue.java
>
>
> Currently all our execution stages dequeue tasks one at a time.  This can 
> result in contention between producers and consumers (although we do our best 
> to minimize this by using LinkedBlockingQueue).
> One approach to mitigating this would be to make consumer threads do more 
> work in "bulk" instead of just one task per dequeue.  (Producer threads tend 
> to be single-task oriented by nature, so I don't see an equivalent 
> opportunity there.)
> BlockingQueue has a drainTo(collection, int) method that would be perfect for 
> this.  However, no ExecutorService in the jdk supports using drainTo, nor 
> could I google one.
> What I would like to do here is create just such a beast and wire it into (at 
> least) the write and read stages.  (Other possible candidates for such an 
> optimization, such as the CommitLog and OutboundTCPConnection, are not 
> ExecutorService-based and will need to be one-offs.)
> AbstractExecutorService may be useful.  The implementations of 
> ICommitLogExecutorService may also be useful. (Despite the name these are not 
> actual ExecutorServices, although they share the most important properties of 
> one.)



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[jira] [Commented] (CASSANDRA-6150) How do I remove the node that has "Host Id is null" ?

2013-10-06 Thread darion yaphets (JIRA)

[ 
https://issues.apache.org/jira/browse/CASSANDRA-6150?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13787529#comment-13787529
 ] 

darion yaphets commented on CASSANDRA-6150:
---

maybe you should kill the cassandra deamon after it decommission from the 
cluster 


> How do I remove the node that has "Host Id is null" ?
> -
>
> Key: CASSANDRA-6150
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6150
> Project: Cassandra
>  Issue Type: Bug
>  Components: Tools
> Environment: CentOS 5.8 , Dell , 32Gb Memory
>Reporter: yunwoo oh
> Fix For: 1.2.3
>
>
> There are 15 Cassandra Node in my team.
> I executed "nodetool -h 192.168.61.131 decommission" .
> and I killed the cassandra deamon
> But when I execute "  ./nodetool status"
> there is 192.168.61.131 node that has "null" value in the "HOST ID" column 
> and State is "Leaving"
> How do I remove the node that has "Host Id is null" ?
> [root@u2metadbm06 bin]# ./nodetool status
> Datacenter: datacenter1
> ===
> Status=Up/Down
> |/ State=Normal/Leaving/Joining/Moving
> --  Address   Load   Tokens  Owns   Host ID   
> Rack
> UN  192.168.61.127187.14 GB  256 2.2%   
> d45096ba-32ea-4fbe-aab3-649879771ffb  rack1
> UN  192.168.61.124191.26 GB  256 2.4%   
> 935804c5-aa5f-4186-b4d3-32352bc80e9c  rack1
> UN  192.168.61.157186.02 GB  256 2.7%   
> edcd56a3-bfc7-4bdd-8bac-da3e64840e9d  rack1
> UN  192.168.61.130186.86 GB  256 2.3%   
> c8a5f722-fedd-4df4-8262-3b49f804ee0d  rack1
> UL  192.168.61.131136.3 GB   256 2.8%   null  
> rack1
> UN  192.168.61.159165.32 GB  256 2.3%   
> 9dc25aa7-1637-43dd-8767-6bd83cd6cfdb  rack1
> .
> thanks.



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