Any caveat in using post_action?

Maxim Dounin mdounin at
Tue Nov 6 14:43:20 UTC 2012


On Tue, Nov 06, 2012 at 09:42:22PM +0800, howard chen wrote:

> Hi,
> I am going to use post_action for mirroring the load for performance
> testing to new backend.
> But according to the doc:
> >> Note: this directive "has subtleties" according to Maxim Dounin, so use
> at your own risk.

There is no official documentation on the "post_action" directive 
(you may check yourself at, and it's on 
purpose.  What you are quoting is wiki.

> Some questions:
> 1. Is the  post_action blocking to the user request? Or the sub request is
> truly async and not affecting to the user?

The post_action is executed in the context of the main request, 
and will block further work on the same client connection till 
it's complete.

That is, it's unlikely a good idea to use post_action for 
performance testing.  I would recommend logging requests instead 
and re-executing them with a separate process.


Maxim Dounin

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