Welcome to “Monitoring Messages”, a new feature from AI Vector. We plan to release, on a bi-weekly basis, a short article related to general monitoring topics and issues. Some of the commentaries will be basic, while others advanced. No matter the levels of complexity or your experience, our intent is to provide something of value. We want you to feel like your time has been justified; hopefully, there will always be a hidden gem.
Sometimes our approach will be humorous. Other times we may irreverently gore some of the Monitoring Industry’s sacred cows. Our goal is to stimulate thought, identify and solve problems.
Let’s give it a shot!
A Few Tips on Using Nagios NRPE for Effective Monitoring of Remote Servers
The first house I bought was thirty years old and had the original roof (with an additional layer of asphalt shingles on top). The pre-loan house inspection came back and our lender required us to replace the roof before they would close our loan. The seller refused to do it, but eventually compromised on buying the shingles. Like most young growing families we had no money and no way to hire a roofer; if we were going to buy the house I was the only “expert” available.
I did as much research as I could, talked to friends who had done “some roofing”, bought a roofing hatchet and set off to conquer the task.
With the help of a friend who had less experience than I, we ripped off the existing roof; and discovered we needed a wide pitch fork to do the job ($)! I realized I hadn’t thought about the rolls of roofing felt ($)! The best way to put down the felt was with staples; I needed a staple hammer ($)… experience is expensive.
I started in the left hand corner of the roof, laid down a starter course, cut down the shingles so they could be staggered and off we went. We got into a good rhythm and things went pretty well; at least that’s what I thought. We got to the peak of the first side of the roof. I got off and went across the street to look at our work. One of the staggers wasn’t cut right and the vertical pattern on the roof was out of line. The exposure (space between horizontal courses) wasn’t straight and dramatically drifted. We applied the experience and mistakes from the first side and actually did a great job on the other side.
For the next ten years we lived with the roof. A few years removed from the experience I had an epiphany – I SHOULD HAVE STARTED WITH THE BACK OF THE HOUSE!!!!!!!
A Hidden Gem – Many users are unaware that on Linux systems you can create a directory and easily include NRPE Configuration files by just dropping them there. This is useful for server deployments.
To make this possible, edit the nrpe.cfg file:
- Add this line “include_dir=/etc/nagios/nrpe”
- Create an NRPE config file directory by typing: “mkdir -p /etc/nagios/nrpe”
- Drop off your NRPE config files and restart NRPE to begin reading them
There are a number of good reasons to use NRPE; we assume you have done your research and your decision is based on sound analysis.
(One of the situations when AI Vector uses NRPE is to distribute and reduce Load)
TIP 1 – Start small – If you don’t have extensive experience with either Monitoring and/or Nagios Configuration, identify a manageable number of devices to start with
TIP 2 – Start with Baseline Services at first – Make your “mistakes” (gain experience) on processes that are easier to implement; also, the data you gain from simple Baselines will be immediately valuable
TIP 3 – Don’t get caught-up with putting together the best Group structure at first; the sophistication and increased effectiveness will come with time
TIP 4 – After you feel comfortable in configuring devices, creating and administrating Groups; involve management and design relevant Business Monitoring Processes that address the needs of both technical and managerial staffs