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Calling SDM web services through a load balancer

Question asked by tony.harrison on Nov 21, 2014
Latest reply on Nov 24, 2014 by buian01

We have several PA solutions that interact with CA ServiceDesk via it's web services, we use several secondary servers specifically for web service calls so as not to impact SD users.


We currently 'load balance' our systems by directing tenant's configuration to use specific secondary servers.


What I would like to do is put a real Load Balancer in front of this group of secondary servers to give us true load balancing and resilience in case one of the secondary servers goes down.


There are issues with session persistence; when you use a PA SDM operator you specify the credentials in the operator as well as the actual web service call you are making; in the background however there are actually 2 web service calls being made:


1. Login - the login web service is called which returns a sessionid which is used in the operator.

2. The actual web service call you want to make e.g. doSelect


The trouble is that the first call, login, is made against one secondary server and the second call could then get load balanced to a different secondary server where the sessionid is invalid.


We need to be able to configure sticky sessions for the PA calls, one possible way would be if the PA web service calls could be made 'cookie aware'; then they could be handled in the same way as a user accessing the SDM GUI in their browser.


Has anybody managed to do this or can anyone shed some light on this area please?