Cassandra often take >30 minutes to write about 300,000 row-mutations when
startup and replaying commitlog!
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From: "Lu Ming" <xl...@live.com>
Sent: Friday, April 16, 2010 11:33 PM
To: <dev@cassandra.apache.org>
Subject: Cassandra 0.5.1 slow down after doing a lot of inserts
Hi:
We have build a storage system with 4 nodes in the cluster. We use the
default configuration file,
every node have 2*E5504 CPU, 8G memory and 6*1T Sata disk. The cluster
stores about 600G data.
We found that Cassandra 0.5.1 ALWAYS slow down after a lot of inserts.
When it happens, CPU and Disk load
are very low. We use "tpstats" nodetools and find that more than 300,000
row-mutations is still pending and
the write speed is no more than 100~200 row-mutations per second.
It also happens when Cassandra starts and replays a large commitlog
file. So we must cost several hours to
wait it finishs startup.
The Faq of Cassandra tells that it is caused by GC? any other
explaining?
thanks a lot.
