Hi Neha, As far as I'm aware, 4GB of RAM is a bit underpowered for Cassandra even if there are no other processes on the same server (i.e. Tomcat and ActiveMQ). There are some general guidelines at http://wiki.apache.org/cassandra/CassandraHardware which should help you out. You may not need all of the recommendations therein if you are simply evaluating Cassandra with a test workload, but I suspect you will at least need more RAM and a dedicated machine to get beyond the read timeouts. Also, when using spinning disks, the 2 drive recommendation is important because Cassandra uses two very different access patterns for its data storage and the disk can be thrashed quite a bit, particularly if you end up using enough memory that virtual memory on the host becomes a factor.
There's a lot of good information on both the Apache Cassandra site and on Planet Cassandra about performance and tuning if you want to know more. Hope that helps, Steve On Thu, Jan 22, 2015 at 7:28 PM, Neha Trivedi <nehajtriv...@gmail.com> wrote: > Hello Everyone, > Thanks very much for the input. > > Here is my System info. > 1. I have single node cluster. (For testing) > 2. I have 4GB Memory on the Server and trying to process 200B. ( 1GB is > allocated to Tomcat7, 1 GB to Cassandra and 1 GB to ActiveMQ. Also nltk > Server is running) > 3. We are using 2.03 Driver (This is one I can change and try) > 4. 64.4 GB HDD > 5. Attached Memory and CPU information. > > Regards > Neha > > On Fri, Jan 23, 2015 at 6:50 AM, Steve Robenalt <sroben...@highwire.org> > wrote: > >> I agree with Rob. You shouldn't need to change the read timeout. >> >> We had similar issues with intermittent ReadTimeoutExceptions for a while >> when we ran Cassandra on underpowered nodes on AWS. We've also seen them >> when executing unconstrained queries with very large ResultSets (because it >> takes longer than the timeout to return results). If you can share more >> details about the hardware environment you are running your cluster on, >> there are many on the list who can tell you if they are underpowered or not >> (CPUs, memory, and disk/storage config are all important factors). >> >> You might also try running a newer version of the Java Driver (the later >> 2.0.x drivers should all work with Cassandra 2.0.3), and I would also >> suggest moving to a newer (2.0.x) version of Cassandra if you have the >> option to do so. We had to move to Cassandra 2.0.5 some time ago from 2.0.3 >> for an issue unrelated to the read timeouts. >> >> Steve >> >> >> On Thu, Jan 22, 2015 at 4:48 PM, Robert Coli <rc...@eventbrite.com> >> wrote: >> >>> On Thu, Jan 22, 2015 at 4:19 PM, Asit KAUSHIK < >>> asitkaushikno...@gmail.com> wrote: >>> >>>> There are some values for read timeout in Cassandra.yaml file and the >>>> default value is 30000 ms change to a bigger value and that resolved our >>>> issue. >>>> >>> Having to increase this value is often a strong signal you are Doing It >>> Wrong. FWIW! >>> >>> =Rob >>> >>> >> >> >
