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From 史英杰 <shiyingjie1...@gmail.com>
Subject Re: Why Cassandra performs better in 15 nodes than in 20 nodes?
Date Mon, 24 May 2010 02:42:26 GMT
Hi,Jonathan
  I am sorry that there is something wrong with the CL I said last time, I
checked the test code agagin. The version we used is 0.6.0-Beta3, and both
the write and read CL are ConsistencyLevel.ONE.

2010/5/24 Jonathan Ellis <jbellis@gmail.com>

> ZERO hasn't been the default CL for a long time.  You should upgrade
> to 0.6.1.  (Read NEWS first to see what has changed.)
>
> 2010/5/23 史英杰 <shiyingjie1983@gmail.com>:
> > The replication factor is 3, and the consistency level is default, zero.
> >
> > 在 2010年5月24日 上午7:25,Jonathan Shook <jshook@gmail.com>写道:
> >>
> >> It would be helpful to know the replication factor and consistency
> >> levels of your reads and writes.
> >>
> >>
> >> 2010/5/23 史英杰 <shiyingjie1983@gmail.com>:
> >> > Thanks for your  reply!
> >> > //Were all of those 20 nodes running real hardware (i.e. NOT VMs)?
> >> > Yes, there are 20 real servers running in the cluster, and one
> >> > Casssandra
> >> > instance runs on each server.
> >> > //Did your driver application(s) run on "real" hardware and how many
> >> > threads
> >> > did you use?
> >> > The clients run on one server of the 20 servers, I used 10 threads to
> >> > run
> >> > the write and read tasks. How many threads can make Cassandra get good
> >> > throughput?
> >> >  Thanks!
> >> > 2010/5/23 Mark Robson <markxr@gmail.com>
> >> >>
> >> >> On 23 May 2010 13:42, 史英杰 <shiyingjie1983@gmail.com> wrote:
> >> >>>
> >> >>> Hi, All
> >> >>>    I am now doing some tests on Cassandra, and I found that both
> >> >>> writes
> >> >>> and reads on 15 nodes are faster than that of 20 nodes, how many
> >> >>> servers
> >> >>> does one Cassandra system contains during the real applications?
> >> >>>    Thanks a lot !
> >> >>>
> >> >>>
> >> >>> Yingjie
> >> >>
> >> >> I'd ask
> >> >> Were all of those 20 nodes running real hardware (i.e. NOT VMs)?
> >> >> and
> >> >> Did your driver application(s) run on "real" hardware and how many
> >> >> threads
> >> >> did you use?
> >> >> Cassandra can only get good throughput with a lot of client threads,
> >> >> not
> >> >> just a few.
> >> >> Mark
> >> >
> >
> >
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of Riptano, the source for professional Cassandra support
> http://riptano.com
>

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