Thanks for reply,I dont know it has some thing to do with linux scheduler but some on suggested about linux scheduler cat /sys/block/sda/queue/scheduler there are quite few of them noop [anticipatory] deadline cfq.I have changed from cfq default to anticipatory,Now problem is less for me kswapd0 take 10-50% of cpu in very short bust less then milliseconds.Also i have changed /proc/sys/vm/pagecache from 100 to 10. Any more suggestion will help me make server better,As for i have read the best scheduler for databases are deadline like for mysql it worked great. On 05/09/2011 06:01 PM, Peter Kjellström wrote: > On Saturday, May 07, 2011 09:35:48 PM Ali Ahsan wrote: >> Hi All >> >> I have xeon server with 16 Gb Ram and no Swap memory.I am running >> cassandra server on two node in cluster.When there is high load on >> server kswapd0 kicks inn and take 100% cpu and make machine very slow >> and we need to restart out cassandra server.I have latest kernel >> 2.6.18-238.9.1.el5.Please let me know how can i fix this issue .Its >> hurting us badly this our production server any quick help will be >> appreciated. > There is more than one bug that causes this behaviour. A few related memory > managent situations (possibly responsible) may actually be avoided if you add > some swap (even if it's not used). My suggestion would be to add some swap, > set swappiness to 0 and see what happens. > > /Peter > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos -- S.Ali Ahsan Senior System Engineer e-Business (Pvt) Ltd 49-C Jail Road, Lahore, P.O. Box 676 Lahore 54000, Pakistan Tel: +92 (0)42 3758 7140 Ext. 128 Mobile: +92 (0)345 831 8769 Fax: +92 (0)42 3758 0027 Email: ali.ahsan at panasiangroup.com www.ebusiness-pg.com www.panasiangroup.com Confidentiality: This e-mail and any attachments may be confidential and/or privileged. If you are not a named recipient, please notify the sender immediately and do not disclose the contents to another person use it for any purpose or store or copy the information in any medium. Internet communications cannot be guaranteed to be timely, secure, error or virus-free. We do not accept liability for any errors or omissions. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20110509/259644f8/attachment-0004.html>