[ 
https://issues.apache.org/jira/browse/AMQ-4987?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

anselme dewavrin updated AMQ-4987:
----------------------------------

    Description: 
Dear all,
I set up a 3-nodes replicatedLevelDB activeMQ cluster as explained on the 
activemq site.

I made a message injector using the php stomp client described here : 
http://stomp.fusesource.org/documentation/php/book.html

Then I injected persistent messages as fast as possible (giving about 100 
messages/s, each message is 10k).

Everything works fine, then I measured the servers' activity with "vmstat 1". I 
saw no iowait on the master node, but  20% on both slaves. This would impeach 
scalabitity I suppose. And the iowait is justified by 3000 bo/s (blocks out) in 
the vmstat report.

The machines are not swapping (paging).

Here is what I tried, without success :
-specify explicitly sync="quorum_mem"
-JNI implementation of the leveldb store (and verified it is used)
-setting flushDelay to 2000

Does anyone have an idea that I could try ? Why is the leveldb slaves writing 
so much to disk ?

Many thanks in advance
Yours,
Anselme

  was:
Dear all,
I set up a 3-nodes replicatedLevelDB activeMQ cluster as explained on the 
activemq site.

I made a message injector using the php stomp client described here : 
http://stomp.fusesource.org/documentation/php/book.html

Then I injected persistent messages as fast as possible (giving about 600 
messages/s).

Everything works fine, then I measured the servers' activity with "vmstat 1". I 
saw no iowait on the master node, but  20% on both slaves. This would impeach 
scalabitity I suppose. And the iowait is justified by 3000 bo/s (blocks out) in 
the vmstat report.

The machines are not swapping (paging).

Here is what I tried, without success :
-specify explicitly sync="quorum_mem"
-JNI implementation of the leveldb store (and verified it is used)
-setting flushDelay to 2000

Does anyone have an idea that I could try ? Why is the leveldb slaves writing 
so much to disk ?

Many thanks in advance
Yours,
Anselme


> io wait on replicated levelDB slaves
> ------------------------------------
>
>                 Key: AMQ-4987
>                 URL: https://issues.apache.org/jira/browse/AMQ-4987
>             Project: ActiveMQ
>          Issue Type: Test
>          Components: activemq-leveldb-store
>    Affects Versions: 5.9.0
>         Environment: debian VM 2.6.32-5-amd64, jdk7
>            Reporter: anselme dewavrin
>            Priority: Minor
>
> Dear all,
> I set up a 3-nodes replicatedLevelDB activeMQ cluster as explained on the 
> activemq site.
> I made a message injector using the php stomp client described here : 
> http://stomp.fusesource.org/documentation/php/book.html
> Then I injected persistent messages as fast as possible (giving about 100 
> messages/s, each message is 10k).
> Everything works fine, then I measured the servers' activity with "vmstat 1". 
> I saw no iowait on the master node, but  20% on both slaves. This would 
> impeach scalabitity I suppose. And the iowait is justified by 3000 bo/s 
> (blocks out) in the vmstat report.
> The machines are not swapping (paging).
> Here is what I tried, without success :
> -specify explicitly sync="quorum_mem"
> -JNI implementation of the leveldb store (and verified it is used)
> -setting flushDelay to 2000
> Does anyone have an idea that I could try ? Why is the leveldb slaves writing 
> so much to disk ?
> Many thanks in advance
> Yours,
> Anselme



--
This message was sent by Atlassian JIRA
(v6.1.5#6160)

Reply via email to