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 <aa...@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.te...@lupa.inf.ufg.br> > wrote: > > I have the same problem! > > 2013/3/11 Alain RODRIGUEZ <arodr...@gmail.com> > >> I can add that I have JNA corectly loaded, from the logs: "JNA mlockall >> successful" >> >> >> 2013/3/11 Alain RODRIGUEZ <arodr...@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 <arodr...@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 > > >
