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?
http://wiki.squid-cache.org/SquidFaq/CacheDigests
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.
Thanks,
Eliezer
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.
