Issuing a Web Service request into Service Desk, when Service Desk is behind a load balancer results in Error 1010 and a failed query.
When Service Desk is behind a load balancer it will balance soap calls to one node, but follow up calls could be routed to the other node, causing an error message "Error 1010" to be displayed.The problem is due to connecting through the load balancer and getting a session ID from one Server and then making a request with that Session ID that is directed by the load balancer to a different Service Desk server.
This behavior is controlled by your Load Balancer, and to some extent the Service Desk engine, and is not related to Process Automation being behind a load balancer as it will occur in single orchestrator environments as well.
Given that this problem lies outside Processes Automation there are only 2 solutions to this issue that we can provide from the Process Automation side:
1. Enable Sticky sessions at the Load Balancer
2. Point Process Automation directly at a specific Service Desk service, bypassing the Load Balancer.
Option 1 is the best solution as it will enable some failover capacity if one of the Service Desk engines is down; Option 2 would only be recommended if you are unable to configure Sticky Sessions at the Load Balancer.