Custom load balancer

A custom script for load balancing? You can't do it at this point.

 

 

With that being said (caveat: I'm not exactly sure what you want), I might look at the following two things:

 

 

1) some combination of a rule and class

 

2) dynamic ratio load balancing (which collects information via SNMP from target hosts to create a weight for load-balancing decisions)

I need to load balancer to be able to query a table in a database before deciding where to send the connection. Based off of this query, it would have an accurate idea of the load on the server. There is really no other way to get this information. Can this be done?

Theoretically, you can also write a custom external monitor (EAV) script that does the database query to get the server load, do some number crunching to get some dynamic ratio, then use iControl's LocalLB::NodeAddress interface to set that dynamic ratio for the node address in question. This does not provide a way for your script to have its own LB algorithm, but at least it provides a way for your script to greatly influence how traffic is load-balanced.

 

 

Loc

That's an interesting idea. I may give that a shot. Has anything like that been done before?

As an alternative, you can also write an iControl application that runs periodically on your servers, gathering server load statistics and other info, then sets the dynamic ratio via iControl.

 

 

This method is a more pro-active way to influence the LB decisions on BIG-IP, and the client apps on the server can be written in any supported language, and used with any SOAP toolkits, of your choice.

 

Loc