Network Monitoring Tools such as PRTG allow you to constantly keep track of your websites. However, sometimes it can be daunting to know what to monitor.
On the one hand, you do not want any website problems to go unnoticed; on the other hand, you should avoid to be flooded by warnings about minor problems. If you constantly get alerts telling you that one subpage of your website is a bit slower than average from one particular location, chances are that you will stop looking at your alerts pretty soon or overlook major problems. You will need to decide exactly what to monitor based on your business and website, but there are a number of general indicators that every website owner should monitor:
Monitoring the availability of your website is without a doubt the single most important part of website monitoring. Ideally, you should constantly check the uptime of your key pages from different locations.
2. Page Speed
Internet users are impatient: if your website does not load fast enough, they will be gone before they even got a glimpse of your site. You can check your website's speed using Ping requests (measuring the time it takes from your location until the website starts loading) and loading time measurements (e.g. measuring the time it takes to download the source code of a web page).
3. Full Page Load Time Including Images, Videos etc.
Although Ping and simple loading time tests give you a feeling for your website speed, they do not tell you how long it takes to load a page completely in a web browser. Special sensors, such as PRTG's Full Web Page Sensor, measure the time it takes to download the page including all embedded page elements, such as Flash content, images, etc.
Please note that this monitoring option can create a lot of bandwidth traffic, depending on the page size and the scanning interval.
4. Error Messages
Check your most important pages for errors, e.g. get an alert if the string "404 Error" is included in the source code.
5. Shopping Cart
If you are running an e-commerce site, making sure that people can buy products online without problems is vital for your business.
Similarly, you should have an automatic testing system in place that alert you if
6. Newsletter Sign-ups
7. Customer Log-ins
do not work properly. To test these processes, your software should include the possibility to follow a defined sequence of URLs.
8. Database Performance
If your website contains dynamic content pulled from a database, check whether the expected values are returned and create alerts if the result contains certain error messages.
9. Geographic Performance
Check your website's availability and speed from different locations. Of course, this is especially important if you are a globally active company, or if your clients come from different parts of the world. But even if you are a local business, you can only benefit from being hitch-freely visible to a worldwide audience. In our last blog post, we described how you can use PRTG to monitor your websites from different locations all over the world using Pingdom integration.
10. Your Web Servers' Free Disk Space
Log files, database entries, video and photo uploads, and the likes create a lot of data on your web servers. To avoid errors and data losses, keep an eye on your free disk space.
11. Your Web Servers' CPU Load
Prevent web server failures by monitoring CPU usage.
Now what if you cannot install monitoring software on your hosted web servers? Consider using a script that publishes the values for available disk space and CPU load to a very simple html page and use an "HTTP Content" sensor to monitor these readings as described here.
12. Website Visitors
Regularly checking the number of visitors to your website helps you to assess the loads your website has to stand and to forecast trends for the future. If the number of visitors is constantly rising, you might have to upgrade your web servers. A sharp fall in visitors can draw your attention to problems with your web site.
Website visitor reports are not a part of web monitoring software such as PRTG, but there are a lot of solutions available, ranging from simple counters to complex analytics tools. If your web analytics tool provides an XML export option, you can use PRTG's "HTTP XML/Rest Value" sensor to monitor any value within the returned XML code.
13. Website Load Tolerance
Do you know how many visitors it takes to considerably slow down your website? Regularly run stress tests and compare the results to your visitor numbers at peak times. Bear in mind that if your company is mentioned in the news or runs an aggressive marketing campaign visitor numbers might soar in a couple of hours. It would be a shame to lose all those visitors just because your website cannot handle them.
14. Broken Links
Use an online link checking tool to find broken links on your site. You can use an on-demand tool like the W3 Link Checker or an advanced link checker like Linktiger that will run periodically and notify you whenever a broken link was found.
15. Website Quality
In addition to monitoring and testing your websites automatically, regularly review your websites manually for spelling errors, outdated content, and overall quality.
If you monitor all these website performance indicators, you will be able to quickly react to any issues. However, if you want to monitor and manage your websites effectively, you should not only react to alerts, but also regularly review your monitoring data. This way you will be able to detect long-time trends and to continuously improve site performance.