Re: Installing Cassandra from Tarball

[Steve Anderson]

I think you’re right Tyler; the warning does not appear after making the 
changes suggested by Bhuvan.

Steve
—
"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 
www.masjidtucson.org


> On 15/06/2016, at 12:26 AM, Tyler Hobbs  wrote:
> 
> 
> On Mon, Jun 13, 2016 at 11:49 AM, Bhuvan Rawal  > wrote:
> 
> 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.
> 
> It looks like swap is actually disabled, but the nofile and nproc limits are 
> too low.
> 
> 
> -- 
> Tyler Hobbs
> DataStax 

Re: Installing Cassandra from Tarball

[Steve Anderson]

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.

Steve
—
"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 
www.masjidtucson.org


> 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 10
> * - 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//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 cassandra-env.sh and provide appropriate jemalloc path
> JVM_OPTS="$JVM_OPTS -Djava.library.path=/lib/"
> 
> WARN  15:41:58 JMX is not enabled to receive remote connections. Please see 
> cassandra-env.sh 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 cassandra-env.sh
> 
> 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
> 

Re: Installing Cassandra from Tarball

[Tyler Hobbs]

On Mon, Jun 13, 2016 at 11:49 AM, Bhuvan Rawal  wrote:

>
> 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.
>

It looks like swap is actually disabled, but the nofile and nproc limits
are too low.


-- 
Tyler Hobbs
DataStax 

Re: Installing Cassandra from Tarball

[Bhuvan Rawal]

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 10
* - 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//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 *cassandra-env.sh* and provide appropriate jemalloc path
JVM_OPTS="$JVM_OPTS -Djava.library.path=/lib/"

WARN  15:41:58 JMX is not enabled to receive remote connections. Please see
> cassandra-env.sh 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 *cassandra-env.sh*

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