Hi Alexis, Thank you for your response.
My commit log is on SSD. which shows me 30 to 40 ms of disk latency. When I ran iostat; I see "await" 26ms to 30 ms for my commit log disk. My CPU is less than 18% used. How I reduce the disk latency for my commit log disk. They are SSDs. Thank you in advance, Jay On Wed, Apr 17, 2013 at 3:58 PM, Alexis Rodríguez < arodrig...@inconcertcc.com> wrote: > :D > > Jay, check if your disk(s) utilization allows you to change the > configuration the way Edward suggest. iostat -xkcd 1 will show you how much > of your disk(s) are in use. > > > > > On Wed, Apr 17, 2013 at 5:26 PM, Edward Capriolo <edlinuxg...@gmail.com>wrote: > >> three things: >> 1) compaction throughput is fairly low (yaml nodetool) >> 2) concurrent compactions is fairly low (yaml) >> 3) multithreaded compaction might be off in your version >> >> Try raising these things. Otherwise consider option 4. >> >> 4)$$$$$$$$$$$$$$$$$$$$$$$ RAID,RAM<CPU$$$$$$$$$$$$$$ >> >> >> On Wed, Apr 17, 2013 at 4:01 PM, Jay Svc <jaytechg...@gmail.com> wrote: >> >>> Hi Team, >>> >>> >>> >>> I have a high write traffic to my Cassandra cluster. I experience a very >>> high number of pending compactions. As I expect higher writes, The pending >>> compactions keep increasing. Even when I stop my writes it takes several >>> hours to finishing pending compactions. >>> >>> >>> My CF is configured with LCS, with sstable_size_mb=20M. My CPU is below >>> 20%, JVM memory usage is between 45%-55%. I am using Cassandra 1.1.9. >>> >>> >>> How can I increase the compaction rate so it will run bit faster to >>> match my write speed? >>> >>> >>> Your inputs are appreciated. >>> >>> >>> Thanks, >>> >>> Jay >>> >>> >> >
