The idea is to provide a quick summary of the current status of your Varnish cache on a HTML page, much like Other Caches[tm], webservers (mod_status) and load balancers have.
Overall plans:
- we'll do a sample-and-hold vmod that stores counters every n seconds and keeps m samples of it. This is done inside varnish.
- (for now this is just a python daemon, to keep going forward)
- the vmod/daemon makes this visible in a sub-URL of your site that you define in VCL.
- the sub-URL provides you with: 1) JSON representation of the stored samples, 2) HTML+Javascript to render it.
Anyone wishing to roll their own metrics can just poll the JSON for themselves.
What we have:
- statusbackend.py runs a HTTPd on port 5912 and serves files in web/. /json is hardcoded in the server and outputs json.
- web/index.html needs some love.
Maybees:
- use socket.io for polling.
- use highcharts (or flot) to do some simple graphs.