Re: [squid-users] external_acl_type ttl,negative_ttl works as expected

From: Amos Jeffries <squid3_at_treenet.co.nz>
Date: Mon, 03 Jun 2013 15:57:35 +1200

On 2/06/2013 6:13 a.m., Oliver Loch wrote:
> Hello,
>
> I'm testing the external_acl_type with some external helpers to see how Squid acts on the results. To see any changes immediately I changed the ttl and negative_ttl options to "1", which should be one second, but Squid still uses cached answers when opening the same URL again.
>
> So for production use it's perfect, but for testing not really.
>
> I wonder if I'm missing something or if there is a minimum value that the setting can't fall below. I've googled but most problems are the opposite of what I have :)
>
> The external acl dummy is just a script that tests if a file exists or not and then returns "ERR" or "OK".

What version of Squid?
There is a grace period parameter whose interaction with the TTL has
caused misunderstandings and bugs in the recent past. 3.1, 3.2, and some
3.3 releases have various permutations of off-by-1 errors in the TTL
value or the grace period which can cause some weirdness at very small
values. The latest 3.3 should be okay, although we have some reports of
weirdness still going on as late as 3.3.4.

Amos
Received on Mon Jun 03 2013 - 03:57:51 MDT

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