--
> From: markuskl...@gmail.com [mailto:markuskl...@gmail.com] On Behalf Of
> Markus Klems
> Sent: Saturday, February 19, 2011 10:53 AM
> To: user@cassandra.apache.org
> Subject: Re: Benchmarking Cassandra with YCSB
>
> Hi,
>
> we sorted out the performance problems and tu
Can you share what numbers you are now getting?
-Original Message-
From: markuskl...@gmail.com [mailto:markuskl...@gmail.com] On Behalf Of Markus
Klems
Sent: Saturday, February 19, 2011 10:53 AM
To: user@cassandra.apache.org
Subject: Re: Benchmarking Cassandra with YCSB
Hi,
we sorted
Hi,
we sorted out the performance problems and tuned the cluster. In
particular, we identified the following weak spot in our setup:
ConcurrentReads and ConcurrentWrites was set to the default values
which were much too low for our setup. Now, we get some serious
numbers.
Thanks,
Markus
On Tue,
Good point. When we looked at the EC2 nodes, we measured 120% CPU utilization
or so. We interpreted this as a false representation of CPU utilization on a
multi-core machine. Our EC2 nodes have 8 virtual cores each.
Maybe Cassandra 0.6.5 is not so good with execution on multi-core systems?
On 1
Initial thoughts are you are overloading the cluster, are their any log lines
about dropping messages?
What is the schema, what settings do you have in Cassandra yaml and what are
CF stats telling you? E.g. Are you switching Memtables too quickly? What are
the write latency numbers?
Also 0.7
Cassandra is very CPU hungry so you might be hitting a CPU bottleneck.
What's your CPU usage during these tests?
On Tue, Feb 15, 2011 at 8:45 PM, Markus Klems wrote:
> Hi there,
>
> we are currently benchmarking a Cassandra 0.6.5 cluster with 3
> High-Mem Quadruple Extra Large EC2 nodes
> (http:
Hi there,
we are currently benchmarking a Cassandra 0.6.5 cluster with 3
High-Mem Quadruple Extra Large EC2 nodes
(http://aws.amazon.com/ec2/#instance) using Yahoo's YCSB tool
(replication factor is 3, random partitioner). We assigned 32 GB RAM
to the JVM and left 32 GB RAM for the Ubuntu Linux fi
