What is the reconnection mechanism of opcua?

[beyondyinjl2]

Use the subscription mode, after the opcua service is disconnected, reconnect
@OverRide
public void onSubscriptionTransferFailed(UaSubscription subscription, StatusCode statusCode)
Clear the subscriber, re-subscribe, this is no problem

However, after the opcua service is disconnected for a long time (one day), it will not reconnect. What is the reconnection mechanism of opcua?

[kevinherron]

An overview of the reconnect sequence is described in Part 4, Section 6.7.

Milo's implementation is mostly handled in SessionFsm/SessionFsmFactory and another FSM that manages the underlying TCP connection.

You can troubleshoot these by turning loggers org.eclipse.milo.opcua.sdk.client.SessionFsm and org.eclipse.milo.opcua.stack.client.ChannelFsm to DEBUG or TRACE level.

I am not aware of any issues with reconnection failing within Milo (though I have seen some servers that have issues with parts of the reconnect sequence like subscription transfers causing the connection to close). The few times there has been an issue on the client side it was somebody who was doing a blocking action that required the session inside one of the callbacks or something like that.