We just upgraded K2 from version 4.6.6 to 4.6.11 on our environments. There are two K2 servers in the environment with a load balancer setup. After the upgrade, some of the functions from K2 workflow API are throwing exceptions.
"Error","EnvironmentServer","15100","Generic","SourceCode.Workflow.Runtime.Management [OpenConnection [string[] names]]","15100 Error occurred, ERROR: Unable to connect to loadbal-k2-abc.com on port 5252. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. ","anonymous","0.0.0.0" "Error","EnvironmentServer","15100","Generic","SourceCode.Workflow.Runtime.Management [SendArchiveX [string[] names]]","15100 Error occurred, ERROR: Unable to connect to loadbal-k2-abc.com on port 5252. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. ","anonymous","0.0.0.0" "Error","EnvironmentServer","15101","Generic","SourceCode.Workflow.Runtime.Management [ReleaseWorklistItem [string[] names]]","15101 Error occurred, ERROR: Unable to connect to loadbal-k2-abc.com on port 5252. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. ","anonymous","0.0.0.0" "Error","System","2025","InternalMarshalError","SourceCode.Hosting.Server.Runtime.HostServerBroker.InternalMarshal","2025 Error Marshalling SourceCode.Workflow.Runtime.Management.WorkflowManagementHostServer.ReleaseWorklistItem, Unable to connect to loadbal-k2-abc.com on port 5252. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. ","","", "Error","System","2025","InternalMarshalError","SourceCode.Hosting.Server.Services.TCPClientSocket.InternalMarshal","2025 Error Marshalling SourceCode.Workflow.Runtime.Management.WorkflowManagementHostServer.ReleaseWorklistItem, Unable to connect to loadbal-k2-abc.com on port 5252. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. " "Error","Communication","8060","ProcessPacketError","SourceCode.Hosting.Server.Services.TCPClientSocket.ProcessMessage","8060 ProcessPacket Error, Unable to connect to loadbal-k2-abc.com on port 5252. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond. "
In the HostServer logs, we can see that the K2 servers are for some reason trying to contact the K2 load balancer. This looks like a change from K2 4.6.6 where this worked perfectly and there were no calls to the load balancer. We also checked the K2 configuration and the load balancer address is not mentioned anywhere.
We also upgraded on an environment without load balancer and it is working without any errors there.
Why is K2 host server trying to connect to the load balancer in K2 4.6.11 and where does it get the address from?