A few months ago I was seeing 12k writes/s on a single EC2 XL. So something is wrong.
My first suspicion is that your client node may be the bottleneck. On Wed, Apr 20, 2011 at 2:56 PM, Alex Araujo <cassandra-us...@alex.otherinbox.com> wrote: > Does anyone have any Ec2 benchmarks/experiences they can share? I am trying > to get a sense for what to expect from a production cluster on Ec2 so that I > can compare my application's performance against a sane baseline. What I > have done so far is: > > 1. Lunched a 4 node cluster of m1.xlarge instances in the same availability > zone using PyStratus (https://github.com/digitalreasoning/PyStratus). Each > node has the following specs (according to Amazon): > 15 GB memory > 8 EC2 Compute Units (4 virtual cores with 2 EC2 Compute Units each) > 1,690 GB instance storage > 64-bit platform > > 2. Changed the default PyStratus directories in order to have commit logs on > the root partition and data files on ephemeral storage: > commitlog_directory: /var/cassandra-logs > data_file_directories: [/mnt/cassandra-data] > > 2. Gave each node 10GB of MAX_HEAP; 1GB HEAP_NEWSIZE in > conf/cassandra-env.sh > > 3. Ran `contrib/stress/bin/stress -d node1,..,node4 -n 10000000 -t 100` on a > separate m1.large instance: > total,interval_op_rate,interval_key_rate,avg_latency,elapsed_time > ... > 9832712,7120,7120,0.004948514851485148,842 > 9907616,7490,7490,0.0043189949802413755,852 > 9978357,7074,7074,0.004560353967289125,863 > 10000000,2164,2164,0.004065933558194335,867 > > 4. Truncated Keyspace1.Standard1: > # /usr/local/apache-cassandra/bin/cassandra-cli -host localhost -port 9160 > Connected to: "Test Cluster" on x.x.x.x/9160 > Welcome to cassandra CLI. > > Type 'help;' or '?' for help. Type 'quit;' or 'exit;' to quit. > [default@unknown] use Keyspace1; > Authenticated to keyspace: Keyspace1 > [default@Keyspace1] truncate Standard1; > null > > 5. Expanded the cluster to 8 nodes using PyStratus and sanity checked using > nodetool: > # /usr/local/apache-cassandra/bin/nodetool -h localhost ring > Address Status State Load Owns > Token > x.x.x.x Up Normal 1.3 GB 12.50% > 21267647932558653966460912964485513216 > x.x.x.x Up Normal 3.06 GB 12.50% > 42535295865117307932921825928971026432 > x.x.x.x Up Normal 1.16 GB 12.50% > 63802943797675961899382738893456539648 > x.x.x.x Up Normal 2.43 GB 12.50% > 85070591730234615865843651857942052864 > x.x.x.x Up Normal 1.22 GB 12.50% > 106338239662793269832304564822427566080 > x.x.x.x Up Normal 2.74 GB 12.50% > 127605887595351923798765477786913079296 > x.x.x.x Up Normal 1.22 GB 12.50% > 148873535527910577765226390751398592512 > x.x.x.x Up Normal 2.57 GB 12.50% > 170141183460469231731687303715884105728 > > 6. Ran `contrib/stress/bin/stress -d node1,..,node8 -n 10000000 -t 100` on a > separate m1.large instance again: > total,interval_op_rate,interval_key_rate,avg_latency,elapsed_time > ... > 9880360,9649,9649,0.003210443956226165,720 > 9942718,6235,6235,0.003206934154398794,731 > 9997035,5431,5431,0.0032615939761032457,741 > 10000000,296,296,0.002660033726812816,742 > > In a nutshell, 4 nodes inserted at 11,534 writes/sec and 8 nodes inserted at > 13,477 writes/sec. > > Those numbers seem a little low to me, but I don't have anything to compare > to. I'd like to hear others' opinions before I spin my wheels with with > number of nodes, threads, memtable, memory, and/or GC settings. Cheers, > Alex. > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
