varnish-top is a handy util for keeping track of our varnish installation (via Denis). From the google-code project page page:
Simply, it is a tool that lets you monitor a few key stats from one or more varnish boxes in real-time, from the command line, in a top-like screen. It's not the most sophisticated tool, but is handy for seeing a real-time view into how your box(es) are doing without needing to set up graphing, open up a browser, etc.
Here's a slightly altered snapshot from iusethis:
varnish-top v0.1 (default port: 8888, color: on, refresh: 3 seconds) INSTANCE USAGE HIT % TIME OBJs EXPIR/s NUKED/s REQ/s 127.0.0.1:8888 5.8% 93.2% 1.0ms 8116 2.0 0.0 20 AVERAGE: 5.8% 93.2% 1.0ms 8116 2.0 0.0 20 TOTAL: 0.1GB/ 2.0GB 1.0ms 8116 2.0 0.0 20