So Cassandra may or may not be faster than your current system when you have a couple connections. Where it is faster, and scales, is when you get hundreds of clients across many nodes.
See: http://techblog.netflix.com/2011/11/benchmarking-cassandra-scalability-on.html With 60 clients running 200 threads each they were able to get 10K writes per second per server, and as you added servers from 48-288 you still got 10K writes per second, so the aggregate writes per second went from 48*10K to 288*10K -Jeremiah ________________________________________ From: Jeff Williams [je...@wherethebitsroam.com] Sent: Tuesday, April 03, 2012 10:09 AM To: user@cassandra.apache.org Subject: Re: Write performance compared to Postgresql Vitalii, Yep, that sounds like a good idea. Do you have any more information about how you're doing that? Which client? Because even with 3 concurrent client nodes, my single postgresql server is still out performing my 2 node cassandra cluster, although the gap is narrowing. Jeff On Apr 3, 2012, at 4:08 PM, Vitalii Tymchyshyn wrote: > Note that having tons of TCP connections is not good. We are using async > client to issue multiple calls over single connection at same time. You can > do the same. > > Best regards, Vitalii Tymchyshyn. > > 03.04.12 16:18, Jeff Williams написав(ла): >> Ok, so you think the write speed is limited by the client and protocol, >> rather than the cassandra backend? This sounds reasonable, and fits with our >> use case, as we will have several servers writing. However, a bit harder to >> test! >> >> Jeff >> >> On Apr 3, 2012, at 1:27 PM, Jake Luciani wrote: >> >>> Hi Jeff, >>> >>> Writing serially over one connection will be slower. If you run many >>> threads hitting the server at once you will see throughput improve. >>> >>> Jake >>> >>> >>> >>> On Apr 3, 2012, at 7:08 AM, Jeff Williams<je...@wherethebitsroam.com> >>> wrote: >>> >>>> Hi, >>>> >>>> I am looking at cassandra for a logging application. We currently log to a >>>> Postgresql database. >>>> >>>> I set up 2 cassandra servers for testing. I did a benchmark where I had >>>> 100 hashes representing logs entries, read from a json file. I then looped >>>> over these to do 10,000 log inserts. I repeated the same writing to a >>>> postgresql instance on one of the cassandra servers. The script is >>>> attached. The cassandra writes appear to perform a lot worse. Is this >>>> expected? >>>> >>>> jeff@transcoder01:~$ ruby cassandra-bm.rb >>>> cassandra >>>> 3.170000 0.480000 3.650000 ( 12.032212) >>>> jeff@transcoder01:~$ ruby cassandra-bm.rb >>>> postgres >>>> 2.140000 0.330000 2.470000 ( 7.002601) >>>> >>>> Regards, >>>> Jeff >>>> >>>> <cassandra-bm.rb> >
