Layer 7 load balancing
- May 16, 2016
I think you've mislead yourself a bit. Unique client is determined by
combination, not just src-ip alone. If your clients share the same IP address, it's not a problem for the balancing results, unless you also use the SourceIP-based persistence method.src-ip:src-port
By default, BigIP balancing occurs once. Once a balancing decision is made, it is locked in which means all L7 requests thereafter will go to the same destination, unless specified otherwise by iRules/LTM policies. So the default is L4 balancing. This will work great for most cases.
In case of HTTP applications (or HTTPS if you do SSL offload in BigIP), you can get per-request-balancing by applying OneConnect profile to your Virtual Server. That would essentially be the L7 balancing you're looking for. OneConnect can significantly improve balancing results in case of low number of end-clients. However, in case of high number of end-clients, you can also get great balancing results without the use of OneConnect.
For best balancing results, general recommendation is to avoid the use of any persistence whenever possible. If the use of persistence cannot be avoided, universal or cookie persistence methods are preferred over SourceIP persistence.
Regards,