cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Hiller, Dean" <Dean.Hil...@nrel.gov>
Subject Re: Why so slow?
Date Mon, 20 Aug 2012 16:16:30 GMT
Be careful on bulk as cassandra takes a bit longer to process.  It was faster not doing too
many rows at a time multithreaded in our performance testing and if I remember Aaron Morton
might have told me that as well.

Definitely use the cassandra bulk testing tool as well.  I used that and compared it to my
tool until I got my tool in par with their tool and you can post the numbers for the cassandra
bulk testing tool and I know there was someone on this list who told me the expected writes/ms(it
was probably Aaron as well).

Later,
Dean

From: Carlos Carrasco <carlos.carrasco@groupalia.com<mailto:carlos.carrasco@groupalia.com>>
Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Date: Monday, August 20, 2012 10:03 AM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Subject: Re: Why so slow?

Are you inserting in bulk? Try to increase the amount of mutations you send in a single batch,
otherwise you are just measuring the TCP roundtrip time.

On 20 August 2012 17:36, Peter Morris <mrpmorris@gmail.com<mailto:mrpmorris@gmail.com>>
wrote:
My misunderstanding, thanks for correcting me!


On Mon, Aug 20, 2012 at 4:32 PM, Hiller, Dean <Dean.Hiller@nrel.gov<mailto:Dean.Hiller@nrel.gov>>
wrote:
There is latency and throughput.  These are two totally different things even for MySQL. 
If you are single threaded, each request (even with MySql) has to be delayed by 1ms or whatever
your ping time is.  To fully utilize a 1Gps bandwidth, you NEED to be multithreaded or you
are wasting bandwidth…and even then, you probably waste bandwidth as one CPU can't always
keep up with keeping the pipe filled.




Mime
View raw message