if this isn't a known issue, lemme do some more investigating. my test client becomes "more random" with reads as time progresses, so possibly this is what causes the latency issue. however, all that being said, the performance really becomes bad after a while.
________________________________________ From: Brian Burruss Sent: Sunday, December 13, 2009 1:14 PM To: cassandra-user@incubator.apache.org Subject: read latency creaping up i've noticed the longer i let my test clients run the higher the read latency becomes. if i kill the clients, the latency drops back down to a reasonable value. write latency isn't affected. here are two cfstats listings from the same machine, the first before and the second after i killed the clients. i do not touch the servers. this seems odd. if the clients are doing some bad, it seems that the server's latency wouldn't be affected. is this a thrift issue? before --------- Keyspace: uds Read Count: 2003 Read Latency: 59.807 ms. Write Count: 65145 Write Latency: 0.047 ms. Pending Tasks: 0 Column Family: bucket Memtable Columns Count: 168751 Memtable Data Size: 351695390 Memtable Switch Count: 94 Read Count: 2003 Read Latency: 59.807 ms. Write Count: 65176 Write Latency: 0.047 ms. Pending Tasks: 0 after ------- Keyspace: uds Read Count: 53249 Read Latency: 3.653 ms. Write Count: 52888 Write Latency: 0.035 ms. Pending Tasks: 0 Column Family: bucket Memtable Columns Count: 383297 Memtable Data Size: 798864312 Memtable Switch Count: 94 Read Count: 53271 Read Latency: 3.649 ms. Write Count: 52937 Write Latency: 0.035 ms. Pending Tasks: 0