cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Steve Anderson <>
Subject Re: Installing Cassandra from Tarball
Date Tue, 14 Jun 2016 17:35:26 GMT
Awesone, thanks Bhuvan! 

I have not worried about the JMX warning at this stage.

There were two other warnings, but I assume these are due to the size of my Amazon Linux Image
(and are not worth worrying about at this stage).

WARN  17:24:20 Small commitlog volume detected at /var/lib/cassandra/commitlog; setting commitlog_total_space_in_mb
to 1983.  You can override this in cassandra.yaml

WARN  17:24:20 Only 5.809GiB free across all data volumes. Consider adding more capacity to
your cluster or removing obsolete snapshots

Regarding the commitlog_total_space_in_mb property, I see from the cassandra.yaml file:

	The default value is the smaller of 8192, and 1/4 of the total space of the commitlog volume.

Awesome, thanks again.

"Surely, those who believe, those who are Jewish, the Christians, and the converts; anyone
who (1) believes in God, (2) believes in the Last Day, and (3) leads a righteous life, will
receive their recompense from their Lord; they have nothing to fear, nor will they grieve."
(Quran 2:62, 5:69) …learn more at

> On 14/06/2016, at 12:49 AM, Bhuvan Rawal <> wrote:
> Hi Steve,
> Please find the responses in line:
> WARN  15:41:58 Unable to lock JVM memory (ENOMEM). This can result in part of the JVM
being swapped out, especially with mmapped I/O enabled. Increase RLIMIT_MEMLOCK or run Cassandra
as root.
>  You can edit - /etc/security/limits.conf and put these lines in there
> * - memlock unlimited
> * - nofile 100000
> * - nproc 32768
> * - as unlimited
> and reload the properties by command $ sudo sysctl -p
> and then checking it :
> $ ulimit -l
> and for the cassandra process by :
> $ cat /proc/<cassandra-pid>/limits
> Source - Datastax Troubleshooting <>
> WARN  15:41:58 jemalloc shared library could not be preloaded to speed up memory allocations
> If you want to allocate off heap memory using jemalloc then uncomment this line in
and provide appropriate jemalloc path
> JVM_OPTS="$JVM_OPTS -Djava.library.path=<JEMALLOC_HOME>/lib/"
> WARN  15:41:58 JMX is not enabled to receive remote connections. Please see
for more info.
> By default JMX is enabled only for local connections, if you want to debug from a remote
machine mark LOCAL_JMX=no  in
> WARN  15:41:58 Cassandra server running in degraded mode. Is swap disabled? : true, 
Address space adequate? : true,  nofile limit adequate? : false, nproc limit adequate? : false
> You need to disable swap in order to avoid this message, using swap space can have serious
performance implications. Make sure you disable fstab entry as well for swap partition.
> Thanks & Regards,
> Bhuvan

View raw message