Re: RE: Cassandra and -XX:+UseLargePages

2011-01-16 Thread Aaron Morton
them long enough.AOn 17 Jan, 2011,at 02:37 PM, David Dabbs wrote: -Original Message- From: Aaron Morton [mailto:aa...@thelastpickle.com] Sent: Sunday, January 16, 2011 7:07 PM To: user@cassandra.apache.org Subject: Re: Cassandra and -XX:+UseLargePages Chris, could you provide some more

RE: Cassandra and -XX:+UseLargePages

2011-01-16 Thread David Dabbs
-Original Message- From: Aaron Morton [mailto:aa...@thelastpickle.com] Sent: Sunday, January 16, 2011 7:07 PM To: user@cassandra.apache.org Subject: Re: Cassandra and -XX:+UseLargePages Chris, could you provide some more info on you experience? Were you using mmapped files? Using row

Re: Cassandra and -XX:+UseLargePages

2011-01-16 Thread Chris Goffinet
DiskAccessMode mmap mlockall() used No row caches Default keycache Default memtable thresholds -Chris On Jan 16, 2011, at 5:06 PM, Aaron Morton wrote: > Chris, could you provide some more info on you experience? Were you using > mmapped files? Using row or key caches? What were the memtabe thre

Re: Cassandra and -XX:+UseLargePages

2011-01-16 Thread Aaron Morton
Chris, could you provide some more info on you experience? Were you using mmapped files? Using row or key caches? What were the memtabe thresholds? Using mlockall() ? There are a couple of issues listed in the first paragraphs here that at first glance may cause issues http://www.oracle.com/te

Re: Cassandra and -XX:+UseLargePages

2011-01-16 Thread Chris Goffinet
I've seen about a 13% improvement in practice. -Chris On Jan 16, 2011, at 4:01 PM, David Dabbs wrote: > Hello. > > Can anyone comment on the performance impact (positive or negative) > of running Cassandra configured to use large pages under Linux? > Yes, YMMV applies, but I thought I'd ask be