Hello,

Dealing with a communication break depends more on its nature than its duration. If there is simply a very long network error that prevents the Client and the Server from exchanging messages, you could use a sufficiently high LifeTimeCount to make sure the Subscription survives the communication break. On the other hand, if the communication break is caused by the Server shutting itself down or crashing, then it doesn’t really matter how high the LifeTimeCount is since recreating the Subscription and its MonitoredItems is required anyway.

The onLifetimeTimeout method of SubscriptionAliveListener interface is called if the Client hasn’t received notifications for longer than its lifetime period, which is the PublishingInterval multiplied by the LifeTimeCount. When the onLifetimeTimeout has been called, you can assume that the Subscription no longer exists on the Server and recreating it is required. However, the automatic reconnect of UaClient will handle recreating Subscriptions when reconnecting to the Server, so you shouldn’t need to recreate it manually.

Are you experiencing a problem with Subscriptions that is not being fixed by the automatic reconnect after the connection break?

Hello,

In most connection breaks, the SDK should automatically handle recreating Subscriptions and MonitoredItems. Therefore, you will just need to make sure the LifeTimeCount has sufficiently high value that a LifetimeTimeout is not triggered due to the Server being slow to respond to Client. Under normal circumstances, Subscriptions should never experience a LifetimeTimeout when connected to a Server, unless the LifeTimeCount is too small.