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Timeouts in Varnish

by Darrell Kingsley last modified Mar 13, 2014 02:10 PM
Sometimes when you have a server process that takes a long time to return, your page may timeout with a Varnish 503. It's easy to fix though.

Varnish has a number of timeouts, most of which don't make it into the default varnish.vcl build by the Plone buildout recipe. This means you end up with the defaults. The 503 is generally caused by the first_byte_timeout. This is set to 60s by default.

To change it, just add the following to your varnish.vcl in

backend backend_0 {
  .host = "";
  .port = "xxxx";
  .first_byte_timeout = 300s;


There are other timeouts, and you can find more detail here: along with some other useful links.