Clarence Eldefors blog - Mostly about the web and technologyClarence Eldefors blog
Varnish comes with several very useful command line tools that can be a bit hard to get the grasp of. The list below is by no means meant to be exhaustive, but give an introduction to some tools and use cases.
Easily seen as a geeky graph with little information, varnishhist is actually extremely useful to get an overview of the overall status of your backend servers and varnish.
The pipes (|) are requests served from the cache whereas the hash-signs (#) are requests to the backend. The X axis is a logaritmic scale for request times. So the histogram above shows that we have a good amount of cache hits that are served really fast whereas roughly half of the backend requests takes a bit more than 0,1s. Like most of the other command line applications you can filter out the data you need with regex, only show backend requests or only cache hits. See https://www.varnish-cache.org/docs/
Clarence Eldefors blog - Mostly about the web and technologyClarence Eldefors blog