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Cassandra Monitoring plugin not working

Posted: Tue Aug 29, 2017 12:51 am
by sandeep09412
Hi,

I am following below documentation for Cassandra monitoring.

https://assets.nagios.com/downloads/nag ... ios_XI.pdf

I am facing issue in executing command on Nagios Xi server.

# /usr/local/nagios/libexec/check_nrpe -H 10.30.0.169 -c cassandra

I am getting this.

CASSANDRA CRITICAL - cannot run /home/user/apache-cassandra-3.0.14/bin/nodetool;

Can you please help me with this.

Re: Cassandra Monitoring plugin not working

Posted: Tue Aug 29, 2017 10:17 am
by bolson
Hello,

This appears to be a configuration issue or a permissions issue. Pleas post the output of the following from the remote host. (The Cassandra host):

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ls -l /home/user/apache-cassandra-3.0.14/bin/nodetool

Re: Cassandra Monitoring plugin not working

Posted: Tue Aug 29, 2017 12:41 pm
by sandeep09412

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-rwxrwxrwx. 1 user user  3359 Jun 20 04:19 nodetool

Re: Cassandra Monitoring plugin not working

Posted: Tue Aug 29, 2017 1:48 pm
by dwhitfield
On the remote host, what is the output of the following

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find / -name nodetool
/home/user/apache-cassandra-3.0.14/bin/nodetool
sestatus
Also, can you please post the exact command you are using...that check_nrpe command is not valid. It may be something simply, but I want to see for sure.

Re: Cassandra Monitoring plugin not working

Posted: Tue Aug 29, 2017 1:55 pm
by bolson
Please execute the following command on your Cassandra server:

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nodetool status 
And post the output.

Re: Cassandra Monitoring plugin not working

Posted: Wed Aug 30, 2017 1:55 am
by sandeep09412
I have checked cassandra is working fine and path to nodetool is correct and nodetool is having executable permission for everyone.

I am executing below caommand on cassandra server as specified in documentation.

# /usr/local/nagios/libexec/check_nrpe -H 10.30.0.169 -c cassandra

I am getting this.
CASSANDRA CRITICAL - cannot run /home/user/apache-cassandra-3.0.14/bin/nodetool;

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[user@localhost libexec]$ nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address    Load       Tokens       Owns (effective)  Host ID                               Rack
UN  127.0.0.1  228.37 KiB  256          100.0%            a3c12454-d92e-4e48-82ae-6e0a19563304  rack1

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[user@localhost bin]$ sestatus
SELinux status:                 enabled
SELinuxfs mount:                /sys/fs/selinux
SELinux root directory:         /etc/selinux
Loaded policy name:             targeted
Current mode:                   enforcing
Mode from config file:          enforcing
Policy MLS status:              enabled
Policy deny_unknown status:     allowed
Max kernel policy version:      28
When i excute the plugin script through perl its working

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[user@localhost libexec]$ perl cassandra.pl 
CASSANDRA OK -  | heap_mem=9.33 
Its giving that issues when the plugin script is run through check_npre

Re: Cassandra Monitoring plugin not working

Posted: Wed Aug 30, 2017 9:44 am
by bolson
I suspect that your issue is related to selinux. Can you disable selinux on that host momentarily as a test?

Re: Cassandra Monitoring plugin not working

Posted: Wed Aug 30, 2017 11:39 am
by sandeep09412
I am using Centos7.

Still same after disableing selinux

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[user@localhost libexec]$ sestatus
SELinux status:                 disabled

Re: Cassandra Monitoring plugin not working

Posted: Wed Aug 30, 2017 1:51 pm
by bolson
Please execute locally on the cassandra host:

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/usr/local/nagios/libexec/check_nrpe -H 127.0.0.1 -c cassandra
And post the result. We need to determine if the issue is communication, authentication, or permissions.

Re: Cassandra Monitoring plugin not working

Posted: Thu Aug 31, 2017 12:55 am
by sandeep09412
To check the issue i have reinstalled cassandra at other place but issue is still there.

Please find below the command output received at cassandra server

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[user@localhost libexec]$ /usr/local/nagios/libexec/check_nrpe -H 127.0.0.1 -c cassandra
CASSANDRA CRITICAL -  cannot run /home/user/Downloads/apache-cassandra-3.11.0/bin/nodetool;
NRPE logs from /etc/log/message for the above command on cassandra server

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[root@localhost log]# tail -f messages 
Aug 31 15:14:39 localhost xinetd[1106]: START: nrpe pid=4304 from=::ffff:127.0.0.1
Aug 31 15:14:40 localhost nrpe[4304]: INFO: SSL/TLS initialized. All network traffic will be encrypted.
Aug 31 15:14:40 localhost nrpe[4305]: ERROR: my_system() seteuid(0): Operation not permitted
Aug 31 15:14:40 localhost xinetd[1106]: EXIT: nrpe status=0 pid=4304 duration=1(sec)
From cassandra server

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[root@localhost ~]# /usr/local/nagios/libexec/check_nrpe -H 10.30.0.169 -c cassandra
CASSANDRA CRITICAL -  cannot run /home/user/Downloads/apache-cassandra-3.11.0/bin/nodetool;
NRPE logs from /etc/log/message for the above command on cassandra server

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[root@localhost log]# tail -f messages 
Aug 31 15:10:32 localhost xinetd[1106]: START: nrpe pid=4208 from=::ffff:10.30.0.206
Aug 31 15:10:32 localhost nrpe[4208]: INFO: SSL/TLS initialized. All network traffic will be encrypted.
Aug 31 15:10:32 localhost nrpe[4209]: ERROR: my_system() seteuid(0): Operation not permitted
Aug 31 15:10:33 localhost xinetd[1106]: EXIT: nrpe status=0 pid=4208 duration=1(sec)