ACE cookie stickiness issue

Question

Hi,
We are having ACE as the load balancer
Software running on ACE
loader: Version 12.2[121]
system: Version A2(1.1a) [build 3.0(0)A2(1.1a) adbuild_22:19:41-2008/07/21_
/auto/adbu-rel3/rel_a2_1_1_throttle/REL_3_0_0_A2_1_1A]
system image file: [LCP] disk0:c6ace-t1k9-mz.A2_1_1a.bin
We have 2 webservers (load balanced) & 2 application servers(load balanced).Cookie based stickiness is currently used on Web & Application servers.
Ideal scenario:
1.Client opens the url http://...There is always a dual session whenever the client opens the url.One is for Java & the other for html.
2.Client--->Webserver1
3.Webserver1---->APP1
Most of the times when the client types the url, the dual sessions goes to one Webserver as per round robin (eg web server 1) & the webserver 1 communicates with Application server as per round robin (eg.application server 1).
Problem:
Now at times when the client types the url, the dual sessions gets split which means one session goes to one webserver & the other session goes to second webserver.Ideally it should not as per the application demands.
When this happens, both the webservers communicates with both the application servers.Here is where the problem happens.The client is asked for the login page again which indicates that the client has went to the second application server for the login.
What ideally should happen is the client should stick to the same application server depending up the sticky timeout.
Foll. is the output of show conns when prob occurs:
Primary-ACE/DMZ2# sh conn serverfarm SF-8888
conn-id np dir proto vlan source destination state
----------+--+---+-----+----+---------------------+---------------------+------+
1321 1 in TCP 2504 172.21.46.34:2037 172.24.51.200:8888 ESTAB
1255 1 out TCP 2704 172.24.51.33:8888 172.21.46.34:2037 ESTAB
1108 2 in TCP 2504 172.21.46.34:2036 172.24.51.200:8888 ESTAB
1144 2 out TCP 2704 172.24.51.32:8888 172.21.46.34:2036 ESTAB
Primary-ACE/APP# sh conn serverfarm SF-8888
conn-id np dir proto vlan source destination state
----------+--+---+-----+----+---------------------+---------------------+------+
959 2 in TCP 2507 172.24.51.32:58306 172.24.54.200:8888 ESTAB
115 2 out TCP 2707 172.24.54.32:8888 172.24.51.32:58306 ESTAB
651 2 in TCP 2507 172.24.51.33:51030 172.24.54.200:8888 ESTAB
901 2 out TCP 2707 172.24.54.33:8888 172.24.51.33:51030 ESTAB
I have attached the configs.
The web server we are testing is 172.24.51.32 & 33 - port 8888
Application servers - 172.24.54.32 & 33-port 8888
Rgds./Sachin

Answer 1

Sachin~
What is exactly your flow?
Is client hitting the Webserver farm (in web server context) and then Web servers hitting the APPs Servers in the APPS server context?
If thats the case (only Web servers are App server clients and client is not hitting application serverfarm ) then you can use source ip based sticky in APP server farm which will ensure that one web server sticks to a particular APP server and it never changes the APP server.
Following example will insert cookie named "Mycookie" in the server responses from APP1 rservers to the client
rserver host App1-Srvr1
ip address 192.168.1.1
inservice
rserver host App1-Srvr2
ip address 192.168.1.2
inservice
serverfarm host APP1-SFARM
rserver App1-Srvr1
inservice
rserver App1-Srvr2
inservice
class-map match-any APP1-VIP
2 match virtual-address 10.10.10.1 tcp eq www
sticky http-cookie MYcookie App1-sticky
cookie insert
timeout 720
replicate sticky
serverfarm App1-Sfarm
policy-map type loadbalance first-match APP1-POLICY
class class-default
sticky-serverfarm App1-sticky
policy-map multi-match VIPS
class VIP-P80
loadbalance vip inservice
loadbalance policy APP1-POLICY
loadbalance vip icmp-reply active
HTH
Syed Iftekhar Ahmed