incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: Row cache off-heap ?
Date Tue, 12 Mar 2013 08:44:59 GMT
I am using C*1.1.6.

"Did you restart the node after changing the row_cache_size_in_mb ?"

No, I didn't. I used the nodetool setcachecapacity and didn't restart the
node.

"The changes in GC activity are not huge and may not be due to cache
activity"

I find them hudge, and just happened on the node in which I had enabled row
cache. I just enabled it on .164 node from 10:45 to 10:48 and the heap size
doubled from 3.5GB to 7GB (out of 8, which induced memory pressure). About
GC, all the collections increased a lot compare to the other nodes with row
caching disabled.

"What is the output from nodetool info?"

I can give it to you but, row cache i now disabled.

Token            : 85070591730234615865843651857942052864
Gossip active    : true
Thrift active    : true
Load             : 201.61 GB
Generation No    : 1362749056
Uptime (seconds) : 328675
Heap Memory (MB) : 5157.58 / 8152.00
Data Center      : eu-west
Rack             : 1b
Exceptions       : 24
Key Cache        : size 104857584 (bytes), capacity 104857584 (bytes),
106814132 hits, 120131310 requests, 0.858 recent hit rate, 14400 save
period in seconds
Row Cache        : size 0 (bytes), capacity 0 (bytes), 0 hits, 0 requests,
NaN recent hit rate, 0 save period in seconds

I think it won't help, but I can't try things now unless we are quire sure
it will work smooth, we are on heavy load.

Anyway, thanks for trying to help once again.




2013/3/12 aaron morton <aaron@thelastpickle.com>

> What version are you using?
>
> Sounds like you have configured it correctly. Did you restart the node
> after changing the row_cache_size_in_mb ?
> The changes in GC activity are not huge and may not be due to cache
> activity. Have they continued after you enabled the row cache?
>
> What is the output from nodetool info?
>
> Cheers
>
>    -----------------
> Aaron Morton
> Freelance Cassandra Consultant
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 11/03/2013, at 5:30 AM, Sávio Teles <savio.teles@lupa.inf.ufg.br>
> wrote:
>
> I have the same problem!
>
> 2013/3/11 Alain RODRIGUEZ <arodrime@gmail.com>
>
>> I can add that I have JNA corectly loaded, from the logs: "JNA mlockall
>> successful"
>>
>>
>> 2013/3/11 Alain RODRIGUEZ <arodrime@gmail.com>
>>
>>> Any clue on this ?
>>>
>>> Row cache well configured could avoid us a lot of disk read, and IO
>>> is definitely our bottleneck... If someone could explain why the row cache
>>> has so much impact on my JVM and how to avoid it, it would be appreciated
>>> :).
>>>
>>>
>>> 2013/3/8 Alain RODRIGUEZ <arodrime@gmail.com>
>>>
>>>> Hi,
>>>>
>>>> We have some issue having a high read throughput. I wanted to alleviate
>>>> things by turning the row cache ON.
>>>>
>>>> I set the row cache to 200 on one node and enable caching 'ALL' on the
>>>> 3 most read CF. There is the effect this operation had on my JVM:
>>>> http://img692.imageshack.us/img692/4171/datastaxopscenterr.png
>>>>
>>>> It looks like the row cache was somehow stored in-heap. I looked at my
>>>> cassandra.yaml and I have the following configuration: row_cache_provider:
>>>> SerializingCacheProvider (which should be enough to store row cache
>>>> off-heap as described above in this file: "SerializingCacheProvider
>>>> serialises the contents of the row and stores it in native memory, i.e.,
>>>> off the JVM Heap")
>>>>
>>>> What's wrong ?
>>>>
>>>
>>>
>>
>
>
> --
> Atenciosamente,
> Sávio S. Teles de Oliveira
> voice: +55 62 9136 6996
> http://br.linkedin.com/in/savioteles
>  Mestrando em Ciências da Computação - UFG
> Arquiteto de Software
> Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG
>
>
>

Mime
View raw message