check nrpe/check nt communication issues

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mbellerue
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Joined: Fri Jul 12, 2019 11:10 am

Re: check nrpe/check nt communication issues

Post by mbellerue »

An intermittent issue. Could be the Nagios side, could be the remote server side. Could be a device somewhere in between. It's hard to tell.
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grayloglearn
Posts: 222
Joined: Thu Jul 06, 2017 8:55 am

Re: check nrpe/check nt communication issues

Post by grayloglearn »

Does agent nsclient.log will have capacity to read what exact error. ?? Could you please suggest this.
I don't think it's issue from nagios server because in a minute it's polling to nearly 600 checks.
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lmiltchev
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Re: check nrpe/check nt communication issues

Post by lmiltchev »

You can enable debugging in the nsclient.ini file:

Code: Select all

level = debug
and restart the NSClient++ service, so that changes can take effect. Then, you can post the nsclient.log and nsclient.ini file on the forum. Hopefully, we will find some clues in there. The assumption is that this is a configuration issue. If this is an intermittent networking issue, it would be a lot more difficult to troubleshoot it.
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grayloglearn
Posts: 222
Joined: Thu Jul 06, 2017 8:55 am

Re: check nrpe/check nt communication issues

Post by grayloglearn »

Observed this CHECK_NRPE: Receive header underflow - only 0 bytes received (4 expected) happening in night hours only.
ssax
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Re: check nrpe/check nt communication issues

Post by ssax »

The general scenario is this:

Things work great during the day, things don't work great during the night

Backups and other high resource intensive tasks (such as vulnerability scanning) are scheduled at night, that's usually what it is.

vMotions/VMWare backups, etc, something is impacting the network or the remote systems.

My assumption is they are backups/other resource intensive tasks. Please investigate those systems directly for load and other issues and find out when backups occur. Then you could use the scheduled downtime or recurring downtime to preemptively predict it to suppress them or adjust your timeouts to be longer and see if that fixes it.
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