Re: High disk I/O during reads

2013-03-25 Thread Jon Scarborough
y is over 100 ms which is really > really slow. I am seeing less than 3ms reads for my cluster which is on > SSD. > Can you also check the nodetool cfhistorgram, it tells you more about the > number of SSTable involved and read/write latency. Somtimes average doesn't > tell you t

Re: High disk I/O during reads

2013-03-24 Thread aaron morton
D. >>>> Can you also check the nodetool cfhistorgram, it tells you more about the >>>> number of SSTable involved and read/write latency. Somtimes average doesn't >>>> tell you the whole storey. >>>> Also check your nodetool tpstats, are there a l

Re: High disk I/O during reads

2013-03-23 Thread Matt Kap
eads for my cluster which is on SSD. >>> Can you also check the nodetool cfhistorgram, it tells you more about the >>> number of SSTable involved and read/write latency. Somtimes average doesn't >>> tell you the whole storey. >>> Also check your nodetool

Re: High disk I/O during reads

2013-03-23 Thread igor
average >> doesn't tell you the whole storey. >> Also check your nodetool tpstats, are there a lot dropped reads? >> >> -Wei >> - Original Message - >> From: "Jon Scarborough" >> To: user@cassandra.apache.org >> Sent: Friday, M

RE: High disk I/O during reads

2013-03-22 Thread Kanwar Sangha
rom: "Jon Scarborough" mailto:j...@fifth-aeon.net>> To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Sent: Friday, March 22, 2013 9:42:34 AM Subject: Re: High disk I/O during reads Key distribution across probably varies a lot from row to row in our case. Most read

Re: High disk I/O during reads

2013-03-22 Thread Jon Scarborough
h" > To: user@cassandra.apache.org > Sent: Friday, March 22, 2013 9:42:34 AM > Subject: Re: High disk I/O during reads > > Key distribution across probably varies a lot from row to row in our case. > Most reads would probably only need to look at a few SSTables, a few mig

Re: High disk I/O during reads

2013-03-22 Thread Wei Zhu
doesn't tell you the whole storey. Also check your nodetool tpstats, are there a lot dropped reads? -Wei - Original Message - From: "Jon Scarborough" To: user@cassandra.apache.org Sent: Friday, March 22, 2013 9:42:34 AM Subject: Re: High disk I/O during reads Key distribution

Re: High disk I/O during reads

2013-03-22 Thread Jon Scarborough
ache.org<mailto:user@cassandra.apache.org>> > Date: Friday, March 22, 2013 8:38 AM > To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" < > user@cassandra.apache.org<mailto:user@cassandra.apache.org>> > Subject: RE: High disk I/O during reads &

RE: High disk I/O during reads

2013-03-22 Thread Kanwar Sangha
apache.org Subject: Re: High disk I/O during reads Did you mean to ask "are 'all' your keys spread across all SSTables"? I am guessing at your intention. I mean I would very well hope my keys are spread across all sstables or otherwise that sstable should not be there as he has

Re: High disk I/O during reads

2013-03-22 Thread Hiller, Dean
38 AM To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" mailto:user@cassandra.apache.org>> Subject: RE: High disk I/O during reads Are your Keys spread across all SSTables ? That will cause every sstable read which will increase the I/O. What compaction are

RE: High disk I/O during reads

2013-03-22 Thread Kanwar Sangha
Are your Keys spread across all SSTables ? That will cause every sstable read which will increase the I/O. What compaction are you using ? From: zod...@fifth-aeon.net [mailto:zod...@fifth-aeon.net] On Behalf Of Jon Scarborough Sent: 21 March 2013 23:00 To: user@cassandra.apache.org Subject: Hig