When people come to talk about monitoring, each one has his own understanding of what is Monitoring.
Not so often people know that there are different kinds of monitoring. We will try to give some definitions.
First, you have 2 main kinds of IT systems monitoring: performance monitoring and availability monitoring.
Performance monitoring tries to give an image of the ongoing performances of the system, while availability monitoring only tests if the system is accessible, whatever the performances are.
But within these 2 large categories, there are many kinds of monitoring, each giving more or less information on the monitored system.
The answer to availability monitoring questions is always yes or not while the answer to performance monitoring questions is a time measure or a percentage. Obvious?
Let’s try list them.
Availability monitoring
- Is my server alive? Ping monitoring is the most known but also the one who gives the less information. A ping tells about the connection link availability and load, the network adapter availability, the network driver standby. We call it Network Availability Monitoring. It’s very useful to just know if your system is alive, but this doesn’t say if your system is reachable by users.
- Is my server reachable? Some tools offer website monitoring by retrieving a URL from the server. This will say that your webserver is alive, and users can reach it. We call it Server’s Availability Monitoring. But this doesn’t say that your application is really working, your database is reachable.
- Is my server fully accessible and serving the functions it is dedicated to? To know that, you will have to run a script that enters the application, and go through specific functionalities, testing return pages from the server to check if the answer is correct. This should include main functions of your application, including login, database access, and main links. We call it Application Availability Monitoring. This can only be done with a scripting professional tool and must include regular updates to follow application life.
Performance monitoring
- What is the load of my connexion link? Ping gives a idea of the link load by observing the ongoing times to get the server’s response. The most important is to check the variation of the response times to appreciate what is the normal response time when the link is not used, and what is the response time when the link is loaded by users’ traffic. We call it Network Performance Monitoring.
- What is the load of my server(s)? And the professional will answer: Load of what? Are you talking about CPU load? Memory load? Number of users? Number of hits? Database? This is Server Performance Monitoring. Depending on the answer and on your budget, you will have to install different tools on your server(s), system tools like Munin, Hyperic and others, or web tools like Webalyzer, or database specific tools. You also have very expensive tools we will not talk about because we are not sure they are as useful as expensive. Different tools, different results, different analyzing ways, different expertise. Now you come into problems if you are not an expert of each tool.
- What is the quality of my website performance, from a user point of view? Are the URL quickly downloaded? Do users feel comfortable browsing my website? To answer these questions, you must measure the full website’s response times, including main functionality, and be able to split it in network, server, database response times to be able analyze and improve user’s experience. We call this Application Performance Monitoring. This you can do with professional tools like ours.
And all these different kinds of monitoring apply to all functions of your server: dummy server, website, mail server, database server. Yes, you may want to ping a database server!
Now, it’s easiest to understand that there is not only one “Monitoring”, but different ones according to goals and budget.
Because to get positive and good results all your architecture must be alive and efficient, Application Monitoring is the one above all others, our choice for you.