Service Monitoring between two servers

[mindspring]

Hi There,

I just wanted to find out what is the best practice in monitoring for example:

A front end server connects to a back end database server ( on a public or private IP)
So essentially I would need to monitor the connection between the front end and back end server. The speed of the response time from the front end web server to the back end database server.
Not the connection from my Nagios server to the back end server.

Thanks

[lmiltchev]

If you wanted to monitor the connection between server A and server B, you could install NRPE on server A, and set up a simple check_ping command in the nrpe.cfg file, e.g.

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command[check_ping]=/usr/local/nagios/libexec/check_ping -H $ARG1$ -w 3000.0,80% -c 5000.0,100% -p 5

Then, you could call the check_ping command via check_nrpe from the Nagios XI server:

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/usr/local/nagios/libexec/check_nrpe -H <ip address of server A> -c check_ping -a '<ip address of server B>'

[mindspring]

Thanks I tried that and I get the the error:

nrpe.cfg on ServerA

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command[check_tcp]=/usr/local/nagios/libexec/check_tcp -H $ARG1$ -p $ARG2$ -w $ARG3$ -c $ARG4$

Command I am running from NAgiosXI server

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./check_nrpe -H SERVERA -c check_tcp -H SERVERB -p 3306
CHECK_NRPE: Error - Could not complete SSL handshake.

I thought that I then might need to add the Server A IP address in nrpe.cfg allowed hosts, which I did but I still seem to get the error.

Am I missing something?

Just to confirm, the allowed hosts in nrpe.cfg - is that meant to be comma separated or space separated as documentation differs in this regards?

Thanks.

[lmiltchev]

1. If you are running NRPE as a "standalone daemon" on server A, then you must enter the IP address of your Nagios XI server on the "allowed_hosts" line in the nrpe.cfg file. These are comma-separated IP addresses!

Example:

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allowed_hosts=127.0.0.1,x.x.x.x

Note: The "x.x.x.x" should be the IP address of your Nagios XI server.

Also, make sure you have this line:

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dont_blame_nrpe=1

Save, exit and restart nrpe, so that changes can take effect.

2. If you are running NRPE under xinetd, then you would need to enter the IP address of your Nagios XI server on the "only_from" line in the /etc/xinetd.d/nrpe file. These are space separated IP addresses!

Example:

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only_from = 127.0.0.1 x.x.x.x

Note: The "x.x.x.x" should be the IP address of your Nagios XI server.
Save, exit and restart xinetd, so that changes can take effect.

3. You can test your check from the command line by running the following on the Nagios XI server:

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./check_nrpe -H SERVERA -c check_tcp -a SERVERB 3306 <warn> <crit>

where <warn> and <crit> values are in seconds (use double here).

Example:

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./check_nrpe -H x.x.x.x -c check_tcp -a y.y.y.y 5693 0.001 0.009
TCP OK - 0.000 second response time on y.y.y.y port 5693|time=0.000367s;0.001000;0.009000;0.000000;10.000000

[benjaminsmith]

Hello @MindSpring,

It's been a while since Ludmil's post with setup instructions. Were you able to start monitoring with NRPE. Let us know how it's going when you have a moment.

Thanks.

[mindspring]

Thanks, this is working great now!

[scottwilkerson]

Thanks, this is working great now!

Great!

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