Re: [squid-users] Re: Squid naps each 3600 seconds !

From: Eliezer Croitoru <>
Date: Sun, 27 Oct 2013 07:19:53 +0200

On 10/25/2013 01:22 AM, Alex Rousskov wrote:
> On 10/24/2013 11:13 AM, Eliezer Croitoru wrote:
>> Out of curiosity,
>> What squid Digest content is?
>> What the Digest rebuild does?
>> Let say an ICP\HTCP request can reflect the Information inside the digest?
OK So now we have the other problem:
ICP is causing the lookup but it will not so called NAP the squid instance.
So we need to see more statistics on this specific digest since it can
be a slow HDD or another issues that causes the digest to be very slow.
"squidclient mgr:store_digest" or
"http://PROXY_IP:FORWARD_PORT/squid-internal-mgr/store_digest" should
give more.
using the "http://PROXY_IP:FORWARD_PORT/squid-internal-mgr/refresh" we
should see how is the HTCP\ICP load would be compared to DIGEST.

Can you share some more information on this machine "Horses" ?
The above can be a key to identify couple very direct things that
results the slow speed of the process.
Also regular statistics list of
"http://PROXY_IP:FORWARD_PORT/squid-internal-mgr/info" can give some
more understanding of the situation.


> Alex.
>> On 10/24/2013 07:54 PM, Alex Rousskov wrote:
>>> On 10/24/2013 07:43 AM, Omid Kosari wrote:
>>>> "digest_generation off" temporary solved problem but needs restart .
>>>> I have
>>>> tested with reload before .
>>> Sounds like you have detected the source of the blocking Squid problem
>>> and confirmed it! The fact that digest generation makes your Squid
>>> unresponsive is essentially a Squid bug, but you might be able to help
>>> Squid by adjusting its configuration. If you want to try it, I suggest
>>> re-enabling digest generation and setting
>>> digest_rebuild_chunk_percentage to 1.
>>> If that works around your problem, great. Unfortunately, I suspect Squid
>>> may still be unresponsive during digest generation time because of how
>>> regeneration steps are scheduled and/or because of an old bug in the
>>> low-level scheduling code of "heavy" events. However, using the minimum
>>> digest_rebuild_chunk_percentage value (1) is still worth trying.
>>>> But i could not use digest benefits anymore . Is there big penalty
>>>> if both
>>>> caches are in same gigabit switch ?
>>> The digest optimization can be significant if the two Squids share a lot
>>> of popular content _and_ it takes a long time for each Squid to get that
>>> content from the internet during a miss.
>>> HTH,
>>> Alex.
Received on Sun Oct 27 2013 - 05:20:10 MDT

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