Forum Discussion
NimbostratusNodes checking their own VIP
Today's challenge. There is a behavior on current windows load balancer where in application requested through VIP from a particular node on the pool will be served from the same node. For eg: If the nodes N1,N2,N3,N4 are part of a pool for a VIP and user attempts to browse the URL using the VIP from N2, then the application should be served from N2.
Would I need a iRUle or a special SNAT? Any help is appreciated.
Sincerely,
Smiley
5 Replies
What_Lies_Bene1Cirrostratus
Why use the F5 at all? This would be very complicated.
Mohamed_LrhaziAltocumulus
It soudns like you want an iRule with the following logic:
On HTTP Request: if: CLIENT_IP is N1 or N2 or N3 or N4: then: node CLIENT_IP and snat automap
- Kevin_Stewart
Employee
Are you suggesting that a process on the back end server makes a separate request to the VIP and needs to persist to itself? If so, is there a way that you can address the internal request (host name, URI variation, etc.) to differentiate it from others? As Steve asked, does it have to go back through the LTM to get to itself?
smiley_dba_1116Weird design, but yes, the nodes in the backend need to be able to hit its own VIP, and when the connection hits the VIP, the orgionating NODE will get a return path to the node that made the request. yes, the separate request to the VIP and it does need to persist to itself.
RGW
- Kevin_Stewart
Let's first concede that the client's request and the node's request are two completely separate things - different TCP sessions, different source addresses, etc. It's basically like persisting two external clients to the same node, which you can imagine wouldn't be the easiest thing to do. It could definitely be done though. For example, if you're willing to perhaps construct a relative URI path that the node would follow and indicate its persistence, that could be an option. Ultimately though, unless you need something from the VIP (some iRule logic for example), your best bet might be to simply trick the server into talking to itself directly via hosts file entry.
