Have you tried to tweak settings like memtable_total_space_in_mb and 
flush_largest_memtables_at?
Also, the compaction manager seems to be pretty busy, take a look at 
in_memory_compaction_limit_in_mb.
And with SSD hardware you should modifiy multithreaded_compaction, 
compaction_throughput_mb_per_sec, concurrent_reads and concurrent_writes.
Of course 2GB of RAM is low but tweak these settings might help you.
Maybe some guru could confirm/infirm that.




De :    Jan Algermissen <jan.algermis...@nordsc.com>
A :     user@cassandra.apache.org, 
Date :  04/09/2013 12:29
Objet : Re: Cassandra shuts down; was:Cassandra crashes



Romain,


On 04.09.2013, at 11:11, Romain HARDOUIN <romain.hardo...@urssaf.fr> 
wrote:

> Maybe you should include the end of Cassandra logs. 

There is nothing that seems interesting in cassandra.log. Below you find 
system.log.

> What comes to my mind when I read your first post is OOM killer. 
> But what you describe later is not the case. 
> Just to be sure, have you checked /var/log/messages? 

Nothing there, just occasional Firewall TCP rejections. 

Somehow I think I am simply overloading the whole cluster (see the hinted 
handoff messages in the log). Could that be due to the limited memory of 
2GB my nodes have? IOW, not enough space to buffer up the writes before 
dumping to disk?

Also, my overall write performance is actually pretty bad compared to what 
I read about C*. Before I thought it was the client doing to much work or 
the network. Turns out that's not the case.

I'd expect C* to sort of just suck in my rather small amount of data - 
must be me, not using the right configuration. Oh well, I'll get there :-) 
Thanks anyhow.

Jan




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