topic Re: Persistant server connections between client sessions in Application Networking

Persistant server connections between client sessions

sabri.khemissa — Thu, 07 Apr 2005 13:03:54 GMT

I want to know how I can configure the CSS to dispatch the client request to the same server connected by the last connection of the client.

Note : The server must use a cookie (which content the server name) installed on the client side.

Thanx in advance for your help.

Re: Persistant server connections between client sessions

Gilles Dufour — Thu, 07 Apr 2005 13:51:40 GMT

you can use arrowpoint cookie.

this is explained at :

http://www.cisco.com/en/US/products/hw/contnetw/ps789/products_tech_note09186a0080094398.shtml

Gilles.

Re: Persistant server connections between client sessions

majasan — Mon, 02 May 2005 19:00:48 GMT

I have a situation with ARRPT cookies.

To brief....I just want to know if this scenario is possible.

Taken the two rules below where there are two different sets of servers 01 and 02 and servers 03 and 04 .

If I make a call to "content RHGAPP_80" the cookie is created and contains the "service SVANWEBAPP01_RHG_8204 " now I make a call to "content RHG_MODELS_80" and the cookie would have to add the "service SVANWEBAPP03_RHG_8204" so now I make a call back to "RHGAPP_80 " the cookie would have to contain the original service "SVANWEBAPP01_RHG_8204" to stick me to the same server from the first call and again if I made my next call back to say models the cookie would have to contain the information about the original service "SVANWEBAPP03_RHG_8204" is it possible.

content RHGAPP_80

vip address 192.168.206.138

protocol tcp

port 80

url "/*" eql app_content

advanced-balance arrowpoint-cookie

add service SVANWEBAPP01_RHG_8204

add service SVANWEBAPP02_RHG_8204

active

content RHG_MODELS_80

add service SVANWEBAPP03_RHG_8204

add service SVANWEBAPP04_RHG_8204

advanced-balance arrowpoint-cookie

vip address 192.168.206.138

protocol tcp

port 80

url "/models/*"

active

Re: Persistant server connections between client sessions

skumar1969 — Tue, 03 May 2005 05:13:06 GMT

On the fly, your config should work. Just add different cookie-strings to the services, they should be unique. Add balance aca in addition to the advanced balance arpt in the CR.

Re: Persistant server connections between client sessions

majasan — Tue, 03 May 2005 14:22:41 GMT

Thanks for your reply.I have some caveats here.

1> adding cookie strings.

May be not possible in my situation as the two servers are serving the same page with identical contents.

2> Adding ACA.

Why would I do that? ACA is another method of LBalancing.Our CSS is ok with load balancing. We are concerned with the "sticky" feature to have client requests stick to a server.

To articulate on the issue at hand.:

Say when I hit the first Rule- RHGAPP_80, I will download a cookie which will have pointers to "service SVANWEBAPP01_RHG_8204 " for example.

Now the cookie file name will be of the sort jmundur@xyz.

When I hit the second rule - RHG_MODELS_80, my cookie will be pointing to "service SVANWEBAPP01_RHG_8204 ". Which will confuse the CSS right?

Because the 2nd rule has no "service SVANWEBAPP01_RHG_8204 ".

So it would rewrite the my first cookie file jmundur@xyz to point to SVANWEBAPP03_RHG_8204".

Now when I go back to the first Rule the same reaction will happen and I will be redirected to a different server ??? I will then be not able to preserve the original sticky situation.

This is where I am concerned. The Cisco Tech suggested ( after my posting here ) that I use path for one service. That way the cookie files are preserved. Is that a good solution.We appreciate your help.

Jasan Mundur

CCIE 6347

Re: Persistant server connections between client sessions

Gilles Dufour — Tue, 03 May 2005 17:34:59 GMT

the problem is that a user will only 1 cookie value per site.

So changing the string is useless.

What you have to do is change the cookie name so the 2 rules use different names.

The command you need is :

arrowpoint-cookie name ?

String to be used in the Name=Value pair for cookie. (Len:

0-31)

Use something else then ARPT for one of the rule.

With this command, each host will keep 2 cookies for your website and will send both of them each time it connects to the site.

The CSS will select the appropriate one for the rule.

Regards,

Gilles.

Re: Persistant server connections between client sessions

Gilles Dufour — Tue, 03 May 2005 17:38:14 GMT

Sorry but I have to correct you here.

First, the cookie string will not help in this case.

Each service already have a unique id.

The problem is the cookie name being used ARPT for both rules.

The RFC explains clearly that the host will only keep 1 value per name and website.

Also, I don't understand the recommendation to use ACA.

This is definitely not something I would recommend *on the fly".

With very few connections ACA can provide strange loadbalancing results.

Thanks for your participation to this forum.

Gilles.

Re: Persistant server connections between client sessions

majasan — Thu, 05 May 2005 18:49:08 GMT

Hi Gilles..

Thanks for your input.

I agree with your correction.String option is not needed for a ARRPT . I read that the ARRPt option creates its own id bsaed on the IP address in the absence of a string for service.

I am reading about the "arrowpoint-cookie path " option. Not much is written for this coommand.

But Cisco Tech is suggesting that I use different arpt paths for each rule. He is not specific if I have to do all the rules or just the rules under one domain/VIP. I see the cookies being created based on the domain-name so I assume that logic is to have diff paths for the two rules only that affect for that domain/VIP.

I guess that is the correct way to approach.

Any inputs- skumar and gdufour.?

Jasan Mundur