Are you writing multiple cf at same time? Please run nodetool tpstats to make sure that FlushWriter etc doesnt have high All time blocked counts. A Blocked memtable FlushWriter may block/drop writes. If thats the case you may need to increase memtable flush writers..if u have many secondary indexes in cf ..make sure that memtable flush que size is set at least equal to no of indexes..
monitoring iostat and gc logs may help.. Thanks Anuj Wadehra From:"Amlan Roy" <amlan....@cleartrip.com> Date:Wed, 1 Apr, 2015 at 9:27 pm Subject:Re: Frequent timeout issues Did not see any exception in cassandra.log and system.log. Monitored using JConsole. Did not see anything wrong. Do I need to see any specific info? Doing almost 1000 writes/sec. HBase and Cassandra are running on different clusters. For cassandra I have 6 nodes with 64GB RAM(Heap is at default setting) and 32 cores. On 01-Apr-2015, at 8:43 pm, Eric R Medley <emed...@xylocore.com> wrote: