Varnishlog busy

Varnishlog is busy (error 503)

Following varnish log and displaying all busy TX pages do

varnishlog -c -m TxStatus:503

Now you can see what/if you have any pages being served a busy/unavailable page (503).

Fixing

I had alot of 503 errors because of a smallish malloc assignment behind webserver serving alot of static pages.

I had to increase the default nuke_limit from 10 to 150 so the cache could be 'cleaned' up. In your startup for varnish add something like:

              -p nuke_limit=150 \
              -p thread_pool_add_delay=2 \
              -p thread_pools=2 \
              -p thread_pool_max=4000 \
              -p thread_pool_min=400 \
              -p sess_workspace=16384 \

I added the last 5 lines as well based on some calculations done in best practises, but haven't really looked much into it yet ( http://kristianlyng.wordpress.com/2010/01/26/varnish-best-practices )

Also, for a list of all options and what they do, visit: https://www.varnish-cache.org/docs/trunk/reference/varnishd.html

Notice

Keep in mind all this is for varnish 3.0.0+!!