Re: C++ Thrift client
Aaron, whenever I get a GCInspector event log, will it means that I'm having a GC pause? Messages about ParNew are GS pauses that went over 200ms. CMS GC has to relatively small pauses during it's cycle. All ParNew GC pauses the application threads, Cassandra is just logging the ones that take over 200ms. If you want to see them all enable the GC logging in /etc/cassanda/cassandra-env.sh Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 18/05/2013, at 10:29 AM, Sorin Manolache sor...@gmail.com wrote: On 2013-05-16 02:58, Bill Hastings wrote: Hi All I am doing very small inserts into Cassandra in the range of say 64 bytes. I use a C++ Thrift client and seem consistently get latencies anywhere between 35-45 ms. Could some one please advise as to what might be happening? Sniff the network traffic in order to check whether you use the same connection or you open a new connection for each new insert. Also check if the client does a set_keyspace (or use keyspace) before every insert. That would be wasteful too. In the worst case, the client would perform an authentication too. Inspect timestamps of the network packets in the capture file in order to determine which part takes too long: the connection phase? The authentication? The interval between sending the request and getting the response? I do something similar (C++ Thrift, small inserts of roughly the same size as you) and I get response times of 100ms for the first request when opening the connection, authentifying, and setting the keyspace. But subsequent requests on the same connection have response times in the range of 8-11ms. Sorin
Re: C++ Thrift client
Aaron, whenever I get a GCInspector event log, will it means that I'm having a GC pause? *Atenciosamente,* *Víctor Hugo Molinar - *@vhmolinar http://twitter.com/#!/vhmolinar On Thu, May 16, 2013 at 8:53 PM, aaron morton aa...@thelastpickle.comwrote: (Assuming you have enabled tcp_nodelay on the client socket) Check the server side latency, using nodetool cfstats or nodetool cfhistograms. Check the logs for messages from the GCInspector about ParNew pauses. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 16/05/2013, at 12:58 PM, Bill Hastings bllhasti...@gmail.com wrote: Hi All I am doing very small inserts into Cassandra in the range of say 64 bytes. I use a C++ Thrift client and seem consistently get latencies anywhere between 35-45 ms. Could some one please advise as to what might be happening? thanks
Re: C++ Thrift client
On 2013-05-16 02:58, Bill Hastings wrote: Hi All I am doing very small inserts into Cassandra in the range of say 64 bytes. I use a C++ Thrift client and seem consistently get latencies anywhere between 35-45 ms. Could some one please advise as to what might be happening? Sniff the network traffic in order to check whether you use the same connection or you open a new connection for each new insert. Also check if the client does a set_keyspace (or use keyspace) before every insert. That would be wasteful too. In the worst case, the client would perform an authentication too. Inspect timestamps of the network packets in the capture file in order to determine which part takes too long: the connection phase? The authentication? The interval between sending the request and getting the response? I do something similar (C++ Thrift, small inserts of roughly the same size as you) and I get response times of 100ms for the first request when opening the connection, authentifying, and setting the keyspace. But subsequent requests on the same connection have response times in the range of 8-11ms. Sorin
Re: C++ Thrift client
(Assuming you have enabled tcp_nodelay on the client socket) Check the server side latency, using nodetool cfstats or nodetool cfhistograms. Check the logs for messages from the GCInspector about ParNew pauses. Cheers - Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com On 16/05/2013, at 12:58 PM, Bill Hastings bllhasti...@gmail.com wrote: Hi All I am doing very small inserts into Cassandra in the range of say 64 bytes. I use a C++ Thrift client and seem consistently get latencies anywhere between 35-45 ms. Could some one please advise as to what might be happening? thanks
C++ Thrift client
Hi All I am doing very small inserts into Cassandra in the range of say 64 bytes. I use a C++ Thrift client and seem consistently get latencies anywhere between 35-45 ms. Could some one please advise as to what might be happening? thanks
