How does the Agent, AE and Tomcat communicates between each other

[Lester Chew]

There are a number of configuration .ini files used by AE, Tomcat and Agents that has server names listed.  For example, at the end of the Windows Agent UCXJWX6.ini, there is a list of ports with AE Server names.  I know that when AE communicates with the Agent, it goes by IP address because we have been told it does not use the server to do a DNS lookup and connect to the agent.

Since the various .ini files have port and server name, when the agent starts, the CP parameter contains the first AE server's name with port. Does the Agent then uses DNS or does it have the IP of the AE server somewhere else?  We have two AE servers.  The same question for Tomcat, in the uc4config.xml.

We are having a DNS server change and trying to determine if there could be any impact because AE uses DNS to connection from Tomcat to AE, AE to Agents, Agents to AE, etc.

Thanks for any input.

[Josef Scharl]

Hi,

I'll try to answer your questions.
 

The Agent uses whatever is specified at the CP parameter to contact the CP when it is started the very first time. Or whenever the [ CP_LIST ] section in the Agent ini File is empty.

In case a DNS is specified the DNS Server will be contacted to resolve it.

 

The initial contacted CP will return a list of all CPs available within the AE system.

The Agent stores this list within its ini file in the [ CP_LIST ] section.

From now, the Agent is using the entries of the [ CP_LIST ] section to connect to the CPs.

 

If the list of all CPs received by the Agent contains IP Adreses or DNS Names depends on the parameter "hostName", which is located in the [ TCP/IP ] section of the Automation Engine's ini file (ucsrv.ini).

 

Note: Existing entries in the [ CP_LIST ] section are not overwritten, so changing the hostName parameter will not change existing [ CP_LIST ] enties. These entries need to be removed beforehand.

Note: The same should be try for the User (tomcat) connections / the uc4confix.xls file.

We are using DNS (fqdn) at the hostName parameter and it works fine for us.

Just give it a try.

 

KR, Josef