MQSeries.net :: View topic

hopsala · Posted: Sun Jun 05, 2011 3:01 am Post subject:

Yo

Got my shiny mqseries.net mug. I'm sipping green tea from it as I write..

I'm trying to design a full-on active-active solution for a broker mainly used for web-services. We have an F5 load balancer here, and I was wondering how I should go about configuring it.
The main issue is how to 'ping' services so the LB knows they're up and running, and knows hows to redirect traffic only to the active nodes. It's not enough to telnet the EG port (or biphttplistener, or the servlet proxy; although I should mention we will probably only use EG native listeners), since it is possible that a flow will crash but the EG and other flows in it are still running. For example
Broker1: EG1 running, MF1 running, MF2 running
Broker2: EG1 running, MF1 running, MF2 dead

This means that the load balancer has to redirect based not only on host:port pairs, but also according to URL, and I need to devise some method to reliably 'ping' URLs without interrupting the flow itself and without code changes. I'm also not super-keen on the 'build an I'm-alive flow that runs mqsilist and returns 0K' approach, which I find rather fugly.

The only solution I came up with so far was to try and HTTP GET the URL, and check that I get 200-OK. Hopefully it's the flow that returns the 200-OK and not the EG listener. Doubly hopefully this doesn't actually start the flow running. Triple hopefully I can GET a non-existing page and still get a 200-OK message. I haven't tested it yet.

Has anyone done this before? Any other ideas?