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From Avinash Lakshman <avinash.laksh...@gmail.com>
Subject Re: Some insight into the slow read speed. Where to go from here? RC1 MESSAGE-DESERIALIZER-POOL
Date Thu, 08 Apr 2010 15:14:55 GMT
The tooth wave in memory utilization could be memtable dumps. I/O wait in
TCP happens when you are overwhelming the server with requests. Could you
run sar and find out how many bytes/sec you are receiving/transmitting?

Cheers
Avinash

On Thu, Apr 8, 2010 at 7:45 AM, Mark Jones <MJones@imagehawk.com> wrote:

> I don't see any way to increase the # of active Deserializers in
> storage-conf.xml
>
> Tpstats more than 8 hours after insert/read stop
>
> Pool Name                    Active   Pending      Completed
> FILEUTILS-DELETE-POOL             0         0            227
> STREAM-STAGE                      0         0              1
> RESPONSE-STAGE                    0         0       76724280
> ROW-READ-STAGE                    8      4091        1138277
> LB-OPERATIONS                     0         0              0
> MESSAGE-DESERIALIZER-POOL         1   1849826       78135012
> GMFD                              0         0         136886
> LB-TARGET                         0         0              0
> CONSISTENCY-MANAGER               0         0           1803
> ROW-MUTATION-STAGE                0         0       68669717
> MESSAGE-STREAMING-POOL            0         0              0
> LOAD-BALANCER-STAGE               0         0              0
> FLUSH-SORTER-POOL                 0         0              0
> MEMTABLE-POST-FLUSHER             0         0            438
> FLUSH-WRITER-POOL                 0         0            438
> AE-SERVICE-STAGE                  0         0              3
> HINTED-HANDOFF-POOL               0         0              3
>
> More than 30 minutes later (with no reads or writes to the cluster)
>
> Pool Name                    Active   Pending      Completed
> FILEUTILS-DELETE-POOL             0         0            227
> STREAM-STAGE                      0         0              1
> RESPONSE-STAGE                    0         0       76724280
> ROW-READ-STAGE                    8      4098        1314304
> LB-OPERATIONS                     0         0              0
> MESSAGE-DESERIALIZER-POOL         1   1663578       78336771
> GMFD                              0         0         142651
> LB-TARGET                         0         0              0
> CONSISTENCY-MANAGER               0         0           1803
> ROW-MUTATION-STAGE                0         0       68669717
> MESSAGE-STREAMING-POOL            0         0              0
> LOAD-BALANCER-STAGE               0         0              0
> FLUSH-SORTER-POOL                 0         0              0
> MEMTABLE-POST-FLUSHER             0         0            438
> FLUSH-WRITER-POOL                 0         0            438
> AE-SERVICE-STAGE                  0         0              3
> HINTED-HANDOFF-POOL               0         0              3
>
> The other 2 nodes in the cluster have Pending Counts of 0, but this node
> seems hung
> indefinitely processing requests that should have long ago timed out for
> the client.
>
> TOP is showing a huge amount of I/O Wait, but I'm not sure how to track
> where the wait is happening below here.  I now have jconsole up and running
> on this machine, and the memory usage appears to be a saw tooth wave, going
> from 1GB up to 4GB over 3 hours, then plunging back to 1GB and resuming its
> climb.
>
> top - 08:33:40 up 1 day, 19:25,  4 users,  load average: 7.75, 7.96, 8.16
> Tasks: 177 total,   2 running, 175 sleeping,   0 stopped,   0 zombie
> Cpu(s): 16.6%us,  7.2%sy,  0.0%ni, 34.5%id, 41.1%wa,  0.0%hi,  0.6%si,
>  0.0%st
> Mem:   8123068k total,  8062240k used,    60828k free,     2624k buffers
> Swap: 12699340k total,  1951504k used, 10747836k free,  3757300k cached
>

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