new DataItem IDs generated at Agent Restart

[neildes2]

Every Time the Agent restarts, the AGENT device is getting new DataItem IDs for the Adapter stats. This is dynamically creating additional Fields in our database to the point where it eventually reaches MAX# fields and generates alarms.
What is causing this?
Is it configurable?
How can I prevent the new DataitemIDs from being created? I would like it to have the same IDs after every restart.

ZIP attached with AGent folder

dups_dataitemIds.zip

[neildes2]

[wsobel]

What version of the agent did you use? I will test with the latest and also document here the method we are using to assign the data item ids.

[wsobel]

The adapter identity is generated using the following:

• If AdapterIdentity configuration option is set, it with use this as the prefix.
• Otherwise it is the following: _ + server + _ + port
  • Where server is always the IP or server name.
  • If SuppressIPAddress is set, it is the first 10 digits of the sha1 digest of the server and port mentioned above.

If the server and port are staying the same, they should always be the same values. I will validate this.

If the server address changes between runs, then the identity will change. To make the identity always the same, the AdapterIdentity can be fixed in the configuration file.

[NeilDes]

So, agents running in a doctor container that get a new IP address every time they reboot would cause this problem?

…

On Fri, Mar 21, 2025 at 11:51 AM William Sobel ***@***.***> wrote: The adapter identity is generated using the following: - If AdapterIdentity configuration option is set, it with use this as the prefix. - Otherwise it is the following: _ + server + _ + port - Where server is always the IP or server name. - If SuppressIPAddress is set, it is the first 10 digits of the sha1 digest of the server and port mentioned above. If the server and port are staying the same, they should always be the same values. I will validate this. If the server address changes between runs, then the identity will change. To make the identity always the same, the AdapterIdentity can be fixed in the configuration file. — Reply to this email directly, view it on GitHub <#533 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AD7Y7IFHQ5MTG4MPZ7GA5Q32VQYRFAVCNFSM6AAAAABZP3YA2OVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDONBTG44DENJTHE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***> [image: wsobel]*wsobel* left a comment (mtconnect/cppagent#533) <#533 (comment)> The adapter identity is generated using the following: - If AdapterIdentity configuration option is set, it with use this as the prefix. - Otherwise it is the following: _ + server + _ + port - Where server is always the IP or server name. - If SuppressIPAddress is set, it is the first 10 digits of the sha1 digest of the server and port mentioned above. If the server and port are staying the same, they should always be the same values. I will validate this. If the server address changes between runs, then the identity will change. To make the identity always the same, the AdapterIdentity can be fixed in the configuration file. — Reply to this email directly, view it on GitHub <#533 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AD7Y7IFHQ5MTG4MPZ7GA5Q32VQYRFAVCNFSM6AAAAABZP3YA2OVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDONBTG44DENJTHE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[wsobel]

That could happen if the IP address of the adapter changes when it reboots. The UUID of the agent device is also dependent on the host address and the port unless AgentDeviceUUID is set to fix it to one UUID.

I'm not sure how the Agent ids and the create unique ids interplay in this case. I'll play around a bit and get back. The Agent device is a special device and may not follow the device rules since it gets created using a different mechanism.

Still, all these ids and identity are configurable.

[wsobel]

I think I found the issue. The MQTT client generates a random client UUID (probably to avoid having both sources and sinks use the same ID). This can be fixed using the MqttClientId configuration option. If multiple MQTT adapters are using the same broker with different topics, this was created to avoid that issue.

A couple of options. I can fix the identity of the adapter to something other than the client ID. This will allow the adapter to always get the same id based on some combination of the broker and topic in the configuration file. It should be a fairly easy change. I can also allow the same override using the AdapterIdentity to force the value to some configured value so there is more consistency.

That should fix the issue since the other devices are coming up using the same ids in the stream.

[neildes2]

I like the fact that I can hard code the adapter Identity. I will test that now.

[wsobel]

I'm making it consistent across the two adapters now. I just need to write a couple of tests. The code is nearly finished.

[neildes2]

So, when you are done with the fix, I should be able to do this?

Adapters {

   shdr{
	AdapterIdentity = "SHDR1"
    Host = localhost
    Port = 7878

   }
   shdr2{
	AdapterIdentity = "SHDR2"
    Host = localhost
    Port = 7879

   }
   mqtt1 {
   		  AdapterIdentity = "MQTT1"
   	    Url = mqtt://172.10.34.12:1883
        MqttUserName = userid
        MqttPassword = "password"
        Topics = "test/#"
     

   }
     mqtt2 {
   		  AdapterIdentity = "MQTT2"
   	    Url = mqtt://172.10.34.13:1883
        MqttUserName = userid
        MqttPassword = "password"
        Topics = "test/#"
     

   }
}

[wsobel]

Just tested and added a test for it. I'll create the pull request.

[neildes2]

You Rock!
Thanks for the quick fix.