Hello, I was wondering if anyone has some examples of a i-rule to persist on primary and secondary nodes for Weblogic v10. I seen some older posts on doing this but they where using jsession uri, We use JSESSION cookies. Thanks,

Have you had a look at this? http://devcentral.f5.com/Wiki/default.aspx/iRules/Weblogic_JSessionID_Persistence.html -Matt

Matt, I have an I-rule that I wrote to successfully persist on JSESSIONID. The issue I am having is that we mirror our weblogic sessions to a fallback server. In order to use this fallback feature while loadbalancing your bea servers with F5 is being able to write an i-rule to grab the JSESSIONID and split it into 3 values cookie, Primary Server, Secondary Server. The catch is that the Primary and Secondary Server Ip, Port is hashed. I'm not real sure that there is a way to decode this hash. So my next thought was to figure out what hash value goes with what IP and hardcode those ip's in the i-rule. The only problem with this is that the hash values change every time you restart the server so that is not a good solution. My question is has anyone seen this, or have been down this road successfully or unsuccesfully. Thanks, Brett

Hi Brett, Can you post a few examples of the cookie values and which primary and secondary server IP's/ports they correspond to? You could potentially try to use a similar method as this example--just change the parsing of the value from the URI to the cookie and replace some of the regexp commands with string functions: http://devcentral.f5.com/Default.aspx?tabid=53&forumid=5&tpage=1&view=topic&postid=18948 Thanks, Aaron

Unfortunately I cannot provide that information being that I work on a restricted site. I have looked at the i-rule you are referencing and it would work if only I can decode the hash to Ip Addresses. -Brett

Hi Brett, If the ID's are true one way hashes, it actually wouldn't actually help to see examples. I wonder if the server which sets the cookie always lists itself as the first node in the jsessionid cookie value? If so, you could keep a mapping of the current hashes and work out which server IP:port a secondary hash corresponds to once that server had set a cookie. Load Balancers and the WebLogic Session Cookie http://download.oracle.com/docs/cd/E11035_01/wls100/cluster/load_balancing.htmlwp1028843 The format of a session cookie is: sessionid!primary_server_id!secondary_server_id where: * sessionid is a randomly generated identifier of the HTTP session. The length of the value is configured by the IDLength parameter in the element in the weblogic.xml file for an application. By default, the sessionid length is 52 bytes. * primary_server_id and secondary_server_id are 10 character identifiers of the primary and secondary hosts for the session. Note: For sessions using non-replicated memory, cookie, JDBC, or file-based session persistence, the secondary_server_id is not present. For sessions that use in-memory replication, if the secondary session does not exist, the secondary_server_id is “NONE”. If that seems plausible, let me know and I'll try to come up with a rough version for you to try testing. Also, can you confirm which LTM version you're running? Thanks, Aaron

JSESSIONID Cookie failover

36 Replies

Chris_Miller
Altostratus
Dec 09, 2010
Aaron - have you seen anyone else using this? We're currently letting mod_weblogic (via apache) direct requests to the proper primary/secondary WL nodes. I'm considering getting rid of the apache boxes but would need to replicate the session replication logic.
hooleylist
Cirrostratus
Dec 09, 2010
Hi Chris,

I haven't tested this iRule with any customers--just here on DC and in a lab with simple tests. I'm not sure how you could use LTM to replicate Apache's session data. What do you have in mind?

Aaron
Chris_Miller
Altostratus
Dec 09, 2010
Posted By hoolio on 12/09/2010 08:21 AM

Hi Chris,

I haven't tested this iRule with any customers--just here on DC and in a lab with simple tests. I'm not sure how you could use LTM to replicate Apache's session data. What do you have in mind?

Aaron

Apache is basically just a reverse proxy in this case. Mod_weblogic runs on apache and because it can talk to the weblogic app instances, it can handle the primary/secondary application instance issue.

I'm pretty much in the same boat as the guy who started this topic but since his last post seemed to relate to him having issues, I was curious whether anything had happened since.
hooleylist
Cirrostratus
Dec 09, 2010
I never heard back from the original poster, so I'm not sure what the problem was.

Okay, so it would be the WebLogic session data that would be mirrored independently of LTM and you'd use the iRule to replace the Apache module which routes based on the jsession primary and secondary ID. If you're able to set something up in your lab and see any issues, email me directly and we can look at it together.

Aaron
Chris_Miller
Altostratus
Dec 09, 2010
Yep...that's indeed what I'm trying to do. I'll let you know if I run into anything. Given F5s partnership with Oracle, I've been somewhat surprised not to see some sort of official plug-in/rule for this type of thing.
hooleylist
Cirrostratus
Jul 30, 2012
I added some additional logic and cleaned up the code. I added the updated version to the Codeshare. If anyone has a chance to test the updated version let me know your results.

https://devcentral.f5.com/wiki/iRules.Weblogic-JSessionID-Persistence-for-Session-Replication.ashx

Thanks! Aaron

Forum Discussion

JSESSIONID Cookie failover

36 Replies

Recent Discussions

Convert Nginx rule to F5 irule

Python code using Parallel-SSH library to connect to F5 BigIP

Change Velos Management IP

I cannot activate the license on BIG-IP-NEXT

HA Sync issue on Active-Active Cluster

Related Content

Weblogic JSessionID Persistence

Configuring AWS HA Failover Across AZs Without EIPs Using F5 Cloud Failover Extension (CFE)

Weblogic JSessionID Persistence for Session Replication

Cisco ACI Endpoint Learning with a BIG-IP HA Failover

Cookie-based DDoS protection