Ryan McGuire created CASSANDRA-5534: ---------------------------------------
Summary: Writing wide row causes high CPU usage after compaction Key: CASSANDRA-5534 URL: https://issues.apache.org/jira/browse/CASSANDRA-5534 Project: Cassandra Issue Type: Bug Affects Versions: 2.0 Reporter: Ryan McGuire Assignee: Jonathan Ellis Introduced in commit e74c13ff08663d306dcc5cdc99c07e9e6c12ca21 there is a significant slow down when creating a wide row with cassandra-stress: Testing with the prior (good) commit I used this to write a single wide row, which completed rather quickly: {code} $ ccm create -v git:60f09f0121e0801851b9ab017eddf7e326fa05fb wide-row Fetching Cassandra updates... Cloning Cassandra (from local cache) Checking out requested branch (60f09f0121e0801851b9ab017eddf7e326fa05fb) Compiling Cassandra 60f09f0121e0801851b9ab017eddf7e326fa05fb ... Current cluster is now: wide-row $ ccm populate -n 1 $ ccm start $ time ccm node1 stress -c 10000 -S 1000 -n 1 Created keyspaces. Sleeping 1s for propagation. total,interval_op_rate,interval_key_rate,latency/95th/99th,elapsed_time 1,0,0,273.3,273.3,273.3,0 END real 0m7.106s user 0m1.710s sys 0m0.120s {code} Using the bugged commit (e74c13ff08663d306dcc5cdc99c07e9e6c12ca21) I get a significant slow down: {code} 02:42 PM:~$ ccm create -v git:e74c13ff08663d306dcc5cdc99c07e9e6c12ca21 wide-row Fetching Cassandra updates... Current cluster is now: wide-row 02:42 PM:~$ ccm populate -n 1 02:42 PM:~$ ccm start 02:42 PM:~$ time ccm node1 stress -c 10000 -S 1000 -n 1 Created keyspaces. Sleeping 1s for propagation. total,interval_op_rate,interval_key_rate,latency,95th,99th,elapsed_time 1,0,0,423.2,423.2,423.2,0 Total operation time : 00:00:00 END real 4m16.394s user 0m2.230s sys 0m0.137s {code} Interestingly, the commit in question just says it's a merge from cassandra-1.2, but I do not see this same slowdown using that branch, this only occurs in trunk. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira