We are proud to be able to present to you our latest product, the Varnish Custom Statistics (VCS). VCS is a product we’ve developed to help you detect and diagnose issues on your Varnish powered website. It produces real-time aggregated statistics from a group of Varnish servers. The statistics produced are then grouped according to keys defined in the VCL and presented in time series. Vstatd aggregates statistics from varnishlog on whatever is important for your objectives. If you for instance have several vhosts served from the same Varnish instance, you may want to see a per-vhost breakdown, and in other cases a per-URL breakdown. VCS will help you pull out these statistics from the information retrieved by varnishlog. It will also help you better identify and diagnose problems in your setup, e.g. identify issues such as whether individual requests are taking too long to respond or whether they are not being cached properly.
The data you collect using VCS can be queried and presented in top lists according to various parameters.
Here are some examples of the type of statistics you may track:
- The URLs that take the longest time to load
- URLs that get most hits
- URLs that get the most 50x response code errors
- Cache hits and cache misses
- Etc., etc.
Vg.no is Norway’s largest online newspaper and is the customer we originally collaborated with to develop Varnish Cache. Vg.no was therefore a natural candidate for beta-testing VCS and to see if it solved the challenges and fulfilled the needs we hoped it would. The feedback we got from Vg.no was very positive to say the least and they now refer to it as “debugging heaven”. Vg.no is currently using VCS for identifying and diagnosing issues in their setup.
Varnish Software will continue to enhance VCS and introduce new functionality. This is what is planned in the near future:
- Integration with the Varnish Administration Console (VAC)
- Top lists based on aggregated time periods
- Summarize statistics across several keys according to a regular expression.
Also please get in touch or comment on this post with any feedback you may have about the VCS, its relevancy and whether it is potentially a useful tool for you as a Varnish user.