Hi,

There is a NodeCache in AddressSpace. You can use
client.getAddressSpace().getCache().setNodeMaxAgeInMillis(nodeMaxAgeInMillis);
to set a maximum age for a node. If node is older than the age, then it will be read again from the server. The default max age is one second.

AddressSpace.getNode will read all Properties of that node also at the same time. So if you read the property “fast enough” then it will not read it from the server.

Note that the value of the node does not change as long as it is in the cache, unless you read the value.

We will provide improvements to this configuration at some point in the future.

Hi,

You are correct, the setValue does not send the value to the server. The setValue is used by the SDK internally when a node read from the server. So for now you must use UaClient’s read/write methods (or clear the node from cache to read again when getNode). With those, you can also read/write multiple values at a time.

“Or otherwise, can I get a node from the server, modify it with set methods and at some point send all the changes to the server ?”
Currently, no.
We hope to provide some other way than just using the UaClient for read/write in the future. We have some ideas, but it’s not trivial to implement (since the connection can be lost; server might reject new values; might accept only some=>the client side node would be inconsistent; not fun to code if every Attribute setter would throw 2 checked exceptions etc.)

The “not supported” should be a service-level error code from the server (which is normal, if the server doesn’t support that feature)
add/deleteNode:
The/That server might not support NodeManagement. In our SDK that is by default not supported. You can enable it with NodeManagerTable.setNodeManagementEnabled(true). Note that if you do, then you should have some user authentication/authorization mechanism in place, for example by adding NodeManagerListeners to NodeManagers.

Query:
Query is not supported by many servers in general. In our SDK, you can support it at application level by adding a NodeManagerTableListener to NodeManagerTable. Its not that well documented at the moment, but it has queryFirst and queryNext methods you can implement. Now on closer look we probably need to add methods to that interface later.. Note that the NodeManagerTableListener is just an “entry-point” for the service call, i.e. there is no logic at SDK level to support Query. Implementing the Query might be non-trivial, unless the whole address space is in a database or similar datastructure.