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From "R. Verlangen" <ro...@us2.nl>
Subject Re: Writes slower then reads
Date Thu, 05 Jan 2012 11:09:53 GMT
As I posted this I noticed that the other node's CPU is running high on
some other cronjobs (every couple of minutes to 60% usage). Is the lack of
more CPU cycles a problem in this case?

Robin

2012/1/5 R. Verlangen <robin@us2.nl>

> CPU is idle (< 10% usage). Disk reads occasionally blocks over 32/64K.
> Writes around 0-5MB per second. Network traffic 0.1 / 0.1 MB/s (in / out).
> Paging 0. System int ~ 1300, csw ~ 2500.
>
>
> 2012/1/5 Philippe <watcherfr@gmail.com>
>
>> What can you see in vmstat/dstat ?
>> Le 5 janv. 2012 11:58, "R. Verlangen" <robin@us2.nl> a écrit :
>>
>> Hi there,
>>>
>>> I'm running a cassandra 0.8.6 cluster with 2 nodes (in 2 DC's), RF = 2.
>>> Actual data on the nodes is only 1GB. Disk latency < 1ms. Disk throughput
~
>>> 0.4MB/s. OS load always below 1 (on a 8 core machine with 16GB ram).
>>>
>>> When I'm running my writes against the cluster with cl = ONE all reads
>>> appear to be faster then the writes.
>>>
>>> Average write speed = 1600us/operation
>>> Average read speed = 200us/operation
>>>
>>> I'm really wondering why this is the case. Anyone got a clue?
>>>
>>> With kind regards,
>>> Robin
>>>
>>
>

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