>Is it possible to configure Cassandra in such a way that a
>node only every asks itself for the data, and if so what sort of
>effect will that have on read performance?
Check out the RingCache class which lets you make your clients smart enough to
ask the right server. (Also, if all nodes have a
I've had a few nodes crash (Out of heap), and when I pull the heap dump, there
are hundreds of thousands of MessageDeserializationTasks in the thread pool
executor, using up GB of the heap. I'm running 0.6.2 on sun jvm u20 and the
nodes are under heavy load. Has anyone else run into this? I have
0.6.0 had some gc issues, (I think
https://issues.apache.org/jira/browse/CASSANDRA-1014) if you see lots of gc
collections in the logs, I'd give 0.6.1 a try, I found it much better.
Anecdotally, the sun jvm performs better than openJDK, and the u19 drop fixes
some jvm bugs that can cause memory
We see this behavior as well with 0.6, heap usage graphs look almost identical.
The GC is a noticeable bottleneck, we've tried jdku19 and jrockit vm's. It
basically kills any kind of soft real time behavior.
From: Masood Mortazavi [mailto:masoodmortaz...@gmail.com]
Sent: Monday, April 19, 2010 4
Has anyone done any tuning on the jvm gc options or are the options included in
bin/cassandra.in.sh basically the best choice?
I'm working on getting our latency as consistent as possible, and the gc likes
to kick off 60+ms periods of unavailability for a node, which for my
application leads t
We also applied this patch to the 0.6 branch and have been running it for a bit
over a week. Works well, would love to see it get into trunk/0.7 proper.
From: Ryan Daum [mailto:r...@thimbleware.com]
Sent: Wednesday, March 31, 2010 11:49 AM
To: user@cassandra.apache.org
Subject: Re: expiring data
I agree it's only a problem with 'small' clusters - but it seems like 'small'
is 'most users'? Even with 10 nodes it looks like a pretty big imbalance if I
add an 11th node, and don't add the other 9 or move a large part of the ring.
Or in practice have folks not had trouble with incremental sca
I wanted to check my understanding of the load balance operation. Let's say I
have 5 nodes, each of them has been assigned at startup 1/5 of the ring, and
the load is equal across them (say using random partitioner). The load on the
cluster gets high, so I add a sixth server. During bootstrap, t
