Re: SSD vs. HDD

2010-11-05 Thread Nick Telford
If you're experiencing high I/O load and not getting any Java OutOfMemory (OOM) errors, you should try to keep your heap size as low as possible as this provides the OS filesystem cache with more memory, which will reduce read I/O load significantly. I'm not familiar the performance of Windows file

Re: SSD vs. HDD

2010-11-04 Thread Alaa Zubaidi
Thanks for the advise... We are running on Windows, and I just added more memory to my system, 16G I will run the test again with 8G heap. The load is continues, however, the CPU usage is around 40% with max of 70%. As for cache, I am not using cache, because I am under the impression that cach

Re: SSD vs. HDD

2010-11-04 Thread Alaa Zubaidi
Its a little bit different than what most people use it for, and that's why we are trying to test it, to see if we can benefit from the speed of writing/reading, scalability when and if we need it, and also the coast. and part of the testing we are doing, is trying to see how many nodes do we ne

Re: SSD vs. HDD

2010-11-04 Thread Juho Mäkinen
Do you really need Cassandra to store just 80 GB data for just four hours? It might be just me, but this sounds like quite far fetched from normal Cassandra usage. Cassandra isn't happy unless you run enough nodes to cover one or two node doing compaction (which hurts the node performance). Are you

Re: SSD vs. HDD

2010-11-04 Thread Nick Telford
If you're bottle-necking on read I/O making proper use of Cassandras key cache and row cache will improve things dramatically. A little maths using the numbers you've provided tells me that you have about 80GB of "hot" data (data valid in a 4 hour period). That's obviously too much to directly cac

Re: SSD vs. HDD

2010-11-04 Thread Peter Schuller
> I am having time out errors while reading. > I have 5 CFs but two CFs with high write/read. > The data is organized in time series rows, in CF1 the new rows are read > every 10 seconds and then the whole rows are deleted, While in CF2 the rows > are read in different time range slices and eventua

Re: SSD vs. HDD

2010-11-03 Thread Eric Rosenberry
Some comments inline... On Wed, Nov 3, 2010 at 1:44 PM, Jonathan Shook wrote: > SSDs are not reliable after a (relatively-low compared to spinning > disk) number of writes. > They may significantly boost performance if used on the "journal" > storage, but will suffer short lifetimes for highly-r

Re: SSD vs. HDD

2010-11-03 Thread Alaa Zubaidi
have a continuous high throughput writes, read and delete, and we are trying to find the best hardware. Is using SSD for Cassandra improves performance? Did any one compare SSD vs. HDD? and any recommendations on SSDs? Thanks, Alaa -- Alaa Zubaidi PDF Solutions, Inc. 333 West San Carlos Street

Re: SSD vs. HDD

2010-11-03 Thread Terje Marthinussen
dra improves performance? Did any one compare SSD vs. > HDD? and any recommendations on SSDs? > > Thanks, > Alaa >

Re: SSD vs. HDD

2010-11-03 Thread Jonathan Shook
some general >> ideas.. >> >> Jonathan Shook >> >> On Wed, Nov 3, 2010 at 2:32 PM, Alaa Zubaidi wrote: >> > Hi, >> > we have a continuous high throughput writes, read and delete, and we are >> > trying to find the best hardware. >> > Is using SSD for Cassandra improves performance? Did any one compare SSD >> > vs. >> > HDD? and any recommendations on SSDs? >> > >> > Thanks, >> > Alaa >> > >> > > >

Re: SSD vs. HDD

2010-11-03 Thread Alaa Zubaidi
athan Shook On Wed, Nov 3, 2010 at 2:32 PM, Alaa Zubaidi wrote: Hi, we have a continuous high throughput writes, read and delete, and we are trying to find the best hardware. Is using SSD for Cassandra improves performance? Did any one compare SSD vs. HDD? and any recommendations on SSDs? Thanks

Re: SSD vs. HDD

2010-11-03 Thread Tyler Hobbs
eral > ideas.. > > Jonathan Shook > > On Wed, Nov 3, 2010 at 2:32 PM, Alaa Zubaidi wrote: > > Hi, > > we have a continuous high throughput writes, read and delete, and we are > > trying to find the best hardware. > > Is using SSD for Cassandra improves performance? Did any one compare SSD > vs. > > HDD? and any recommendations on SSDs? > > > > Thanks, > > Alaa > > > > >

Re: SSD vs. HDD

2010-11-03 Thread Jonathan Shook
some general ideas.. Jonathan Shook On Wed, Nov 3, 2010 at 2:32 PM, Alaa Zubaidi wrote: > Hi, > we have a continuous high throughput writes, read and delete, and we are > trying to find the best hardware. > Is using SSD for Cassandra improves performance? Did any one compare SSD

SSD vs. HDD

2010-11-03 Thread Alaa Zubaidi
Hi, we have a continuous high throughput writes, read and delete, and we are trying to find the best hardware. Is using SSD for Cassandra improves performance? Did any one compare SSD vs. HDD? and any recommendations on SSDs? Thanks, Alaa