Transparent Cache; Need separation for YouTube.

Question

Gurus,
here I'm again trying to get some insight to my clients cache issues:
We recently wanted to separate Youtube traffic from the global cache pool and make a separate 3-cache pool, we hit a major issue, the moment we added the paramters/class-maps/policy-maps, we saw ACE dropping 80% of normal existing traffic and we were left with an outage of the web, the ACE just wont pass traffic, even after we removed the class-maps and polices and reloading the ACE module , had to reboot the c6500s
Here the config:
YOUTUBE SERVERFARM:
rserver host BCXX
description BC-YOUTUBE-x
ip address X.X.X.X
inservice
rserver host BCYY
description BC-YOUTUBE-y
ip address Y.Y.Y.Y
inservice
rserver host BCZZ
description YOUTUBE -z
ip address Z.Z.Z.Z
inservice
serverfarm host LEASTCONNECTIONS_FARM
description Transparent Proxy Least Connection Farm
transparent
failaction purge
predictor leastconns slowstart 60
probe PORT_80
rserver BC05
inservice
rserver BC06
inservice
rserver BC07
serverfarm host YOUTUBE_FARM
transparent
failaction purge
predictor roundrobin
probe PORT_80
rserver BC-YOUTUBE-x
inservice
reserver BC-YOUTUBE-y
inservice
rserver BC-YOUTUBE-z
inservice
class-map type http loadbalance match-any YOUTUBE-1
2 match http header Host header-value "www.youtube.com"
class-map type http loadbalance match-any YOUTUBE-2
2 match http url /get_video.*
sticky ip-netmask 255.255.255.255 address both STICKY_SF
timeout 30
timeout activeconns
replicate sticky
serverfarm LEASTCONNECTIONS_FARM
policy-map type loadbalance first-match TRANSPARENT_LB_PM
class YOUTUBE-1
serverfarm YOUTUBE_FARM
class YOUTUBE-2
serverfarm YOUTUBE_FARM
class class-default
sticky-serverfarm STICKY_SF
, We saw some buffer crunches but not sure, we are running A2(1.3) .
last year we had same config with ONLY mathcing URL /get_video.* and was working fine with dest_ip hashing,
this time we added the host www.youtube.com and 3 separate caches.
doesnt seem to make sense to us,
if anyone has worked to segregate U-tube , do share their config philosophy.
we are thinking about separate context or diff policies, but that's too much config related, still all options open.
do let me now champs..
Shukla.

Answer 1

if you had to reboot the cat6k this is not a ACE issue.
The ACE module sits inside the cat6k but should be considered as an external device.
To separate Youtube traffic you need a new feature of A2(1.4) to hash the secondary cookie value.
CSCsq99736: ACE predictor hash url should not stop parsing at "?" delimiter
All video in youtube comes from the same url but with an option "watch?v=9LMTClqvCGs"
What you need to do is hash the value which can be done with A2(1.4).
This will guarantee that you always get to the same cache for the same video.
But your total meltdown was not the result of ACE.
Sth else must have happened.
If ACE was the problem, a reboot of ACE w/ a known-working config should have been enough.
Try not to reboot as a way to fix problems.
Call the TAC and let them troubleshoot your issue live.
Gilles.