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From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: Row cache off-heap ?
Date Thu, 14 Mar 2013 07:46:52 GMT
Thanks, I'll let you know when I'll do so. But any Idea about the increase
of the heap used if all seems to be well configured ? Should I raise a
ticket since we are at least 3 having this issue from what I saw in the
mailing list ?


2013/3/14 aaron morton <aaron@thelastpickle.com>

> > No, I didn't. I used the nodetool setcachecapacity and didn't restart
> the node.
> ok.
>
> > 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.
>
> If the row cache provider is set to serialising, and the node restarted,
> under 1.1X it will us the off heap cache.
>
> At start up look for the log line
> "Initializing row cache with capacity of {} MBs and provider {"
>
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Consultant
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
> On 12/03/2013, at 1:44 AM, Alain RODRIGUEZ <arodrime@gmail.com> wrote:
>
> > 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
> >
> >
>
>
>
> -----------------
> Aaron Morton
> Freelance Cassandra Consultant
> New Zealand
>
> @aaronmorton
> http://www.thelastpickle.com
>
>

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