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From Chi Shin Hsu <>
Subject Some problems with stress testing
Date Fri, 16 Dec 2011 11:04:47 GMT
Hi, all

I am confused by my stress testing result.

The test environment:
One Cassandra node, one client
The size of each row is 1MB, and the client write 100000 rows continually.
Totally data size is 100GB.

First, my client connected  to the server by 100Mbs Ethernet.
The result was 7.3MB/s.
I think this must be limited by the Ethernet speed, so I put the client and
server on the same node.

However the speed was almost slower than Ethernet!

My computer:
CPU: i7 920

I noticed the message of Cassandra.

1. When the Cassandra keeps flushing the cf, and the client gets timeout
exception very frequently.
2. The heap is always full, so I set it bigger to 2G, and the memtable size
is 768MB.

Is it caused by my hard disk's speed? memory size? or any setting?

Any idea?

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