ace stickyness

[followurself]

need help to understand what sticky entries are expected to be seen under show sticky database and for all it options.

we are not sure what cookie values are used by the servers. if i understood right

if servers dont send any cookie , then ACE will use the configured static cookie value and send the cookie to client on behalf of the server. if ace receives the cookie value from server then it forwards the info to the client. in this situation what configuration is required to maintain stickyness

below is my config..

sticky http-cookie sfarm1-sticky sticky-cookie-insert-8005

cookie insert

replicate sticky

serverfarm sfarm1-apache

policy-map type loadbalance first-match sfarm1-apache-8000_pol

class class-default

sticky-serverfarm sticky-cookie-insert-8005

policy-map multi-match VIPS

class sfarm1-apache-8000-cl

loadbalance vip inservice

loadbalance policy sfarm1-apache-8000_pol

loadbalance vip icmp-reply active

Thanks

[Syed Iftekhar Ahmed]

ACE supports parsing HTTP headers up to 64K bytes.

By default ACE Module can parse 4096 bytes (4K).

By default for ACE appliance can parse 2048 bytes.

You can change it to a higher number, for example to instruct ACE to parse 8192 bytes

parameter-map type http My_HTTP_PARAMS

set header-maxparse-length 8192

policy-map multi-match My-VIPS

class Syed

loadbalance vip inservice

loadbalance policy syed-policy

loadbalance vip icmp-reply active

appl-parameter http advanced-options My_HTTP_PARAMS

Increasing it to a very high number will have performance impacts.

More details at

ACE Module:

http://www.cisco.com/en/US/docs/interfaces_modules/services_modules/ace/v3.00_A2/configuration/slb/guide/classlb.html#wp1350453')">http://www.cisco.com/en/US/docs/interfaces_modules/services_modules/ace/v3.00_A2/configuration/slb/guide/classlb.html#wp1350453

ACE Appliance:

http://preview.cisco.com/en/US/docs/app_ntwk_services/data_center_app_services/ace_appliances/vA3_1_0/configuration/slb/guide/classlb.html#wp1062867')">http://preview.cisco.com/en/US/docs/app_ntwk_services/data_center_app_services/ace_appliances/vA3_1_0/configuration/slb/guide/classlb.html#wp1062867

Syed Iftekhar Ahmed

[jteixido]

Giles,

I have a situation that some of the servers in my network generates the cookie and some don't. I already configured the ACE to generate the cookie:

sticky http-cookie acecookie Sticky-Insert-Cookie

cookie insert

serverfarm prodtest-testserver

Do I have to insert a command for the servers that generate their own cookie? If yes please attached a sample config.

Thank you,

John...

[Syed Iftekhar Ahmed]

If you are inserting cookie via ACE & using that cookie for persistence then it doesn't matter if Servers are generating cookies or not.

You either use Dynamic cookie learning (where ACE learns Server generated cookies from server responses & use these cookies for persistence)

or Cookie insertion (where ACE inserts cookie by itself & uses that for persistence).

Syed Iftekhar Ahmed

[followurself]

Thanks Syed,

our current version is 3.0.0 A1 , and the guide shows it support 2048 bytes.

interestingly we dont see any RST packet sent back to the browser.

we are looking to upgrade to A2 version , which by default supports 4096 as mentioned by you

hopefully this will fix the white page issue

thanks

[Syed Iftekhar Ahmed]

Even with your current version you can change the default 2048 byte size to test it out.

Syed

[dinoantonucci]

About hash alghoritm to create cookie Value: hash of serverfarm name + rserver name + port, last parameter "port", what's this port? source client port, vip port or probe server port?

Dino

[paul.pink]

I just wanted to ask 3 questions regarding static cookies. 1) I think this thread is great, but does the web client care what the server sends as a cookie header if the ACE is going to insert its own cookie, send it to the client and maintain session stickiness via the static cookie definition.

2. Does the ACE send cookie information over to the server?

3. what is the best way to verify that the session stickiness is working?

Thank you for your reply.

[Kristopher Martinez]

It is the destination rserver port. A2(1.4) will allow you to look at the cookie variables and hash with the following output:

sdcn/context1# sh sticky cookie-insert group test-cookie-insert

Cookie | HashKey | rserver-instance

------------+----------------------+----------------------------------------+

R669151895 | 11778970594399315428 | https-900-901-2/10.91.100.105:443

R670337816 | 3650464631298052714 | https-900-901-2/10.91.100.106:443

R671523737 | 7818026631770276497 | https-900-901-2/10.91.100.107:443

R672709658 | 7993671127559957208 | https-900-901-2/10.91.100.108:443

Regards

Kris

[dinoantonucci]

About hash alghoritm to create cookie Value: hash of serverfarm name + rserver name + port, last parameter "port", what's this port? source client port, vip port or probe server port?

Dino

[tech_trac]

Hello,

Is it a good idea to use the client cookie (via dynamic learning) in case the server does not generate any cookie.

What are the disadvantages of using client cookies. Secondly, how does client build the cookie value. Is it the browser decision or something else. And for how long the client maintains the same cookie value. I believe in this case, clients around the world would come in with a huge number of distinct cookie values, thereby building up the sticky table.

Thanks.

[tech_trac]

A client cookie example:

Cookie: ASP.NET_SessionId=h2ob4p55m3zzlev4e5uy3b55

[tech_trac]

Hi,

With cookie based stickiness, I tried 'show sticky database static client IP' but it does not show the specific entry.

show sticky database static does show the sticky entries as well as show conn address IP.