Subscribe to a larg Number of Nodes

[benjamin]

Hello,

we are trying to subscribe to many Nodes (>= 500k). Is there a possibility to create a Event Type that Changes of several values could be send by one Event? Another problem we have is that the Event only contains the node identifier, is there a possibility that the values could be send with the event? Is there any other possibility to reduce the notifications?
We are also developing a server which provide this values.
Our requirements are 1000 objects where each object has 500 values. We already try to create a event type but there we only have one SourceNode and SourceName but no list of changed Nodes.
The values changes each 10 seconds so each 10 seconds this 500000 values could change.
Would arrays improve our performance or is the object with values the standard solution? How do other work with such issues?

[Support Team]

Hello Benjamin,

You have to create a DataMonitoredItem for each variable you want to subscribe. If the Variable is an array with 500 elements you only have 1000 variables. If one of the 500 elements changes its value, the complete array need to be transfered, because the Array content has changed. You can create DataMonitoredItem for each Individual Node and subscribe all of them, however EventTypes shall not be used for DataChanges.
Note that a server may limit the number of MonitoredItems per subscription. Some servers also have a maximum of MonitoredItems per call, e.g. a maximum of MonitoredItems for CreateMonitoredItems.