Varnish LiveTM is a mobile app that shows the performance of Varnish instances and the web app/website in question in a visual/graph format, allowing for instant visual confirmation of status or potential performance problems. Varnish Live is an add-on product for Varnish Cache Enterprise, and it works solely within the enterprise version of Varnish. In order for this mobile app to function, it requires Varnish Custom Statistics(VCS)TM to serve data in JSON format. The app illustrates the following different performance indicators:
Overview: This page shows the real-time data on unique users, transfer rate, origin error rate and request rate in one place. Except for unique users, all the numbers displayed are per second.
Unique users: Number of unique users at the current point of time.
Transfer rate: Size of the response body per second.
(Origin) Error rate: Number of errors at the backend server per second. This is not errors at the Varnish server.
Cache hit: This means that the majority of requests are fulfilled by an object already present in cache and no backend request is made.
Cache miss: The object comes from the backend after not being found in the cache.
Request rate: Number of requests the Varnish server responded to. This is the total number of cache hits and cache misses.