Hey all,
I'm attempting to run Cassandra 2.1.2 on a smallish 2.GB ram instance over
at Digital Ocean. It's a CentOS 7 host.
But I'm having some difficulty there. Cassandra will start with no problems
and run for a while. But then choke on the lack of memory and crash. This
is what the system looks like after a reboot:
[root@web2:~] #free -m
total used free shared buffers cached
Mem: 2002 568 1433 8 20 207
-/+ buffers/cache: 340 1661
Swap: 0 0 0
After I start cassandra and leave it running for a few minutes, this is
what the memory situation looks like:
[root@web2:~] #free -m
total used free shared buffers cached
Mem: 2002 1669 332 8 21 359
-/+ buffers/cache: 1288 713
Swap: 0 0 0
I've been able to find this article on how to tune memory for Cassandra on
the datastax site:
http://www.datastax.com/documentation/cassandra/2.0/cassandra/operations/ops_tune_jvm_c.html
So I tried setting up the MAX_HEAP_SIZE and HEAP_NEW_SIZE like this in
cassandra-env.sh:
MAX_HEAP_SIZE="800M"
HEAP_NEWSIZE="200M"
And I gave the latter 200MB based on the fact that this VM has 2 cores:
[root@web2:/etc/alternatives/cassandrahome] #grep name /proc/cpuinfo
model name : QEMU Virtual CPU version 1.0
model name : QEMU Virtual CPU version 1.0
So, 100MB per core basically.
And I've found that this will run for a while.. like maybe 5 or 6 hours!!
So it does stay up a while. But then it finally will crash due to the lack
of memory.
Are there any tricks I can try or things I can do to get Cassandra to stay
runing happily in this amount of space? I'm just using test data and this
is an exercise to learn more about cassandra. I realize a 'real' data set
will require more resources in terms of memory.
Thanks!
Tim
--
GPG me!!
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