What is IT Monitoring?
The essence of IT monitoring is simple, which is to ensure that your IT equipment is available and performing to the level expected and required to maintain ‘business as usual’ .
In basic monitoring solutions this is often done by simply sending a ‘ping’ to the device and awaiting a response. If a response is obtained, then the user can be assured that the server or router or switch is ‘up’ and hasn’t been powered off or crashed etc. This function allows a system administrator a simple view into their IT estate, and to ensure that IT systems are available at the most basic level.
More advanced monitoring solutions allow detailed views into the operational status of those devices, i.e.
“I know that my server is up and running, I also want to make sure that the hard drive doesn’t run out of space”. This is called a service check; checking that hard drive is working, that the CPU isn’t 100% busy, etc. This leads us onto the hierarchical approach to monitoring.
Monitoring Philosophy: A Hierarchical Approach
Monitoring systems have a selection of objects that fit together. In order to monitor our server’s C:/ drive, we must ﬁrst monitor our server. This is obvious. However sometimes the syntax and naming is very confusing, given that it often differs from vendor to vendor with some calling the server a “host” or a “monitor”, and some calling the C:/ drive style checks “monitors”, “service checks”, “counters”, etc. In the following paragraph, hopefully this syntax should become clearer as we step through each of the “3 layers”.
The Foundation Layer
The ﬁrst of our 3 layers is “the foundation layer”. This layer of monitoring forms the basis of the advanced monitoring discussed later. Here we monitor our physical or virtual devices, called ‘hosts’ such as a Windows server, Linux server, Cisco router, Nokia ﬁrewall or VMware virtual machine, etc. These are often the lowest level of the ‘stack’ and we ensure they are up by pinging them.
Once conﬁgured, this allows us a view such as the image shown (below) of the hosts we have added and which ones are up or down.