OPC UA Client Connection Timeout

Hi, We are using the OPC UA Module in our Ignition Server 7.9.5. We use the opc-ua-sdk 1.1.1 version in our application to connect to the OPC UA Module. We noticed this weird behavior where our connections to OPC UA Server failing due to timeout. This is not during startup, this happens after while i.e after successful connection for some hours suddenly all our client connection call timeout. The mitigation is to restart the OPC Module in our server. Can someone help us in finding what could be the cause of this issue? Interestingly this happens only in Ignition Server 7.9.5, we don’t see the same issue in older version ignition.


Client Side:

``scheduler.TaskWorker: Failure executing task: name=[Random Taxk Nme] java.lang.RuntimeException: java.util.concurrent.ExecutionException: io.netty.channel.ConnectTimeoutException: connection timed out: | at com.google.common.base.Throwables.propagate(Unknown Source) | at com.daemon.OpcUaEndpointDiscovey```

Server Side:

I don’t have enough information to figure out what’s wrong, but here are some observations based on this log message + looking at the logs you sent to support:

  1. the last time the UA module started up it bound to but your client error message mentions trying to connect to

  2. your client is opening 25-50 connections and sessions at a time for some reason, and then they are all timing out at once sometime later. I don’t know if this is related to the problem or not, but it’s certainly odd.

  3. to me, a “connection timed out” error indicates something other than the server software is the problem. Connection refused, sure, but usually when we see a “connection timed out” issue it’s because a firewall, proxy, or something on the host system is blocking the TCP connection from happening.

I’d guess that if you had Wireshark running on both sides you’d see the server never sees a TCP SYN packet, or the client never receives the SYN/ACK response packet.