Re: [squid-users] ICAP on Solaris

On 29/10/11 00:23, Justin Lawler wrote:
> Hi,
>
> We're using ICAP on Solaris for squid 3.1.16 and we're seeing some strange behavior.
>
> When cache is disabled and/or using 'ufs' caching policy, all works ok, but if we change to 'aufs' and enable caching, we're seeing REQMOD's coming through, but no 'RESPMOD's.
>

Note that REQMOD is asking about the client request. Before it gets
satisfied by Squid. It gets "called" for all requests.

Whereas, RESPMOD is asking about some reply, which has *already* been
satisfied by some server. It _never_ gets "called" on TCP_HIT.

http://wiki.squid-cache.org/Features/ICAP#Squid_Details

Most of what you describe is expected behaviour (cache enabled == less
RESPMOD).
  Having same/more RESPMOD with UFS despite caching enabled sounds like
a bug.

> We see the same issue on 3.0.15.
>
> Is this a known issue - or anybody see this before? Could it be a configuration option? Should we consider sticking with ufs, or changing to 'diskd'?
>

It has not been mentioned in this way before. Though maybe was described
in other terms.

Note that the I/O system functions used to read/write data onto HDD in
no way affects the decision about whether to pass traffic over the
network to ICAP.

However, if one method of I/O were corrupting the objects during load it
could cause Squid to abandon the cached object and fetch a new one. This
would appear as similar behaviour to what you describe for UFS with
caching enabled.

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.16
   Beta testers wanted for 3.2.0.13