Forum Discussion
raul_rodriguez_
Nimbostratus
NimbostratusMulti-tier application - Maintaining persistence/state
Application Logic:
Client--HTTP-->VIP(tier1)-->Tomcat webserver--TCP:8009-->VIP(tier2)----------->JDK1.4.2_06:Tomcat server
I need to be able to loadbalance both tiers, with persistence based on the Client IP. In other words I need "state" maintained between the Client, webserver and the JKD:Tomcat server. But if a new client connects to the same webserver (tier1) it should be able to send this new clients requests to the 2nd JDK:Tomcat server...etc.
Can I do this with an iRule? and how?
Thanks.
- So tomcat is connecting to the tier2 vip? Is tomcat simply forwarding the request? Does it preserve the request headers and cookies? Is it transparent, i.e. does it preserve the client IP address? You should be able to do this with iRules provided that there is some information to persist on.
- Are both the tier 1 and tier 2 VIP's hosted on the same BIGIP?
To reiterate, it sounds like you want the persistence to be applied jointly to both tiers. So, in example, when a new client comes in, they are load balanced to a webserver, and then in turn load balanced to a Tomcat server. However, when the same client returns, they are persisted to both the same webserver and Tomcat server? Is this correct?
This sounds like it would work just fine by using universal persistence on the JSESSIONID cookie at both tiers. An example of that can be found in this posting: Click here
http://devcentral.f5.com/default.aspx?tabid=28&view=topic&forumid=5&postid=2111 
raul_rodriguez_Yes, both Tier Vip's are on the same BIGIP.
Yes, you are correct- I need persistence through both tiers.
I will investigate...Thanks for your help.
Brian_Gupta_115Am a bit confused about persistence in a URI parsing iRule. What is the order of precedence?
I have a rule that sends requests that begin with /service1 to pool service1, and sends requests that begin with /service2 to pool service2. (The client will be navigating between the two URIs).
Will seperate persistence entries for each pool be maintained? Or can there be only one per VIP/client? (I am using simple source persistence for the VIP).
Thanks,
Brandorr- By default, separate persistence entries are maintained for each pool. That is, the pool is an implicit key for a persistence record unless the "across_pools" attribute is enabled on the persistence profile.
