The Monitoring Triplets: Availability, Speed, and Usage
Merely implementing a Network Monitoring solution for your network is not enough. The biggest part of the work begins right after choosing and installing a monitoring solution. Now it is time to select which aspects of your network you are going to monitor.
Availability
The top priority of Network Monitoring should be the availability of your website and services inside the LAN. Is your site accessible? Does your mail server currently and reliably accept emails sent to and from your company? Is your leased line working properly? Is the service provider (a leased line company or service provider) adhering to their SLA?
Speed
Speed is the second most important factor to monitor. A site that loads slowly makes the Web surfers move on to faster sites and ultimately results in the loss of customers. Your Web server needs to provide optimum performance throughout the day - regardless of current load. Through constant monitoring, you can determine whether you get the full capacity of speed throughout the day and whether there are major fluctuations. Only the data gathered through constant monitoring over an extended period will help you in providing proof to your service provider about any negligence with their services. In addition, monitoring allows you to keep an eye on the usage pattern and to plan accordingly. If you observe a constant rise in the usage pattern, it is better to upgrade before you or your employees start to experience problems.
Also, remember that, apart from the server speed, your Web page can also be sluggish due to too many images or the use of large images. Using website analysis tools to find problems like inappropriately large image files on a Web page an essential part of website optimization.
To learn more about the performance of your website under stress, you should consider running a load/stress testing application. For more details, please refer to the sections about Site Inspector and Web server Stress Tool later in this book.
Usage
Various statistics related to usage also need to be monitored, such as the CPU load that your Web server shows. Does the load increase? Do you need to increase the capacity? You also need to figure out the amount of load on your leased line and whether your service provider is charging you too much for the usual traffic or sudden rises in traffic. If you (re-)sell leased line capacity or bandwidth, how do you calculate each customerâ??s usage in order to get the adequate amount of bandwidth?
This posting is part of an ongoing article series about the basics of network monitoring by Dirk Paessler.