Weblogic JSessionID Persistence
Problem this snippet solves:
Contributed by: unRuleY, Summarized by: deb
Note: The previous version of this iRule contained escaped newlines following the session command, which in versions 10.0 - 10.2.0 causes TMM to core as documented in CR135937 / SOL11427. This was fixed in 10.2.1.
See this related Codeshare example for details on how to take advantage of session replication on the WebLogic servers with targeted node failover in an iRule.
Provides persistence on the jsessionid value found in either the URI or a cookie.
When a request is received, the iRule first looks for a "jsessionid" cookie, and if not found, for a "jsessionid" parameter in the requested URI. If either is found, a persistence record is created if it doesn't already exist, or followed if it does. If neither is found, the request is load balanced according to the load balancing method applied to the virtual server and persisted based on the client's IP address.
In order to ensure the second and subsequent requests follow the first, LTM must create a persistence record indicating the pool member to which the first request was load balanced. If the server is setting the jsessionid in a cookie, the persistence key value may be extracted from the server response to create the persistence record. If the server is setting the jsessionid in the URLs, source address persistence with a short timeout is recommended to track the original destination until the jsessionid is sent.
How to use this snippet:
To ensure a new persistence record is followed when a request is re-load balanced in a client-side Keep-Alive connection, apply a OneConnect profile to the virtual server.
The iRule assumes the jsessionid is in upper case when used as a cookie name. If this isn't the case, please update the example.
To persist on jsessionid, create the iRule below and create a custom Universal persistence profile, with Match Across Services enabled, that uses the iRule. Then use this custom Universal persistence profile as the Default Persistence profile on your Virtual Server. Applying a Fallback Persistence profile of type Source Address Affinity with a host mask and a short timeout (the default source_addr persistence profile will do the trick) to your Virtual Server is also recommended.
Attention, if you are running firmware 11.0 - 11.2.1 and enabled "Match Across Services"! There is a bug inside. SOL14061
This iRule requires LTM v10. or higher.
Code :
when HTTP_REQUEST {
# Log details for the request
set log_prefix "[IP::client_addr]:[TCP::client_port]"
log local0. "$log_prefix: Request to [HTTP::uri] with cookie: [HTTP::cookie value JSESSIONID]"
# Check if there is a JSESSIONID cookie
if { [HTTP::cookie "JSESSIONID"] ne "" }{
# Persist off of the cookie value with a timeout of 1 hour (3600 seconds)
persist uie [string tolower [HTTP::cookie "JSESSIONID"]] 3600
# Log that we're using the cookie value for persistence and the persistence key if it exists.
log local0. "$log_prefix: Used persistence record from cookie. Existing key? [persist lookup uie [string tolower [HTTP::cookie "JSESSIONID"]]]"
} else {
# Parse the jsessionid from the path. The jsessionid, when included in the URI, is in the path,
# not the query string: /path/to/file.ext;jsessionid=1234?param=value
set jsess [findstr [string tolower [HTTP::path]] "jsessionid=" 11]
# Use the jsessionid from the path for persisting with a timeout of 1 hour (3600 seconds)
if { $jsess != "" } {
persist uie $jsess 3600
# Log that we're using the path jessionid for persistence and the persistence key if it exists.
log local0. "$log_prefix: Used persistence record from path: [persist lookup uie $jsess]"
}
}
}
when HTTP_RESPONSE {
# Check if there is a jsessionid cookie in the response
if { [HTTP::cookie "JSESSIONID"] ne "" }{
# Persist off of the cookie value with a timeout of 1 hour (3600 seconds)
persist add uie [string tolower [HTTP::cookie "JSESSIONID"]] 3600
log local0. "$log_prefix: Added persistence record from cookie: [persist lookup uie [string tolower [HTTP::cookie "JSESSIONID"]]]"
}
}
