Hi all, i have this problem : testing your OPC UA Client, i wrapped it into an OSGi bundle ( i’m working on Eclipse Equinox).
I created a simple thread that writes every second a random integer value on a MemoryBased variable (I’m using Kepware OPC UA Server).

If i register my variable on a MonitoredDataItemListener, the java process memory (Private Bytes) raises from 151 mb to 155 mb in less than an hour.
Instead, if i don’t use a MonitoredDataItemListener, and maintain the same write procedure, the process memory is more stable (~0.2 Mb in 30 minutes).

I’m not able to understand if this is a real leak, or it is a normal memory fluctuation, and with a long-time run it disappears….is it possible to run the evaluation library for an entire day (and not only for 2 hours)?

Otherwise, this is my write procedure :

public void writeItem(String itemFullName, Object value) throws Exception {
//translate itemFullName, i.e. MB.LW_MONITOR.LW_HEART_BEAT_TH1 , in a ReferenceDescription
ReferenceDescription found=util.getItemReference(itemFullName);
NodeId nodeId=client.getNamespaceTable().toNodeId(found.getNodeId());
UaNode node = client.getAddressSpace().getNode(nodeId);
if(node==null) throw new Exception(“Null node!”);
UaVariable v = (UaVariable) node;
if (v.getDataType() == null)
v.setDataType(client.getAddressSpace().getType(v.getDataTypeId()));
UaDataType dataType = (UaDataType) v.getDataType();
Object convertedValue=null;
try {
convertedValue = dataType != null ? client.getAddressSpace().getDataTypeConverter().parseVariant(value.toString(), dataType): value;
} catch (Exception e) {
logger.log(LogService.LOG_ERROR,”writeItem ERROR on writing [“+itemFullName+”] as [“+value+”] : ” + LogUtils.getMessageAndStackTrace(e));
}
boolean status = client.writeAttribute(nodeId, Attributes.Value,convertedValue);
if(!status)
logger.log(LogService.LOG_WARNING, “Item “+itemFullName+” written ASYNCROUSLY @ “+value);
}

I register the item using this procedure (my test item is member of an OPC Group, and i register all the variables of this group):

// get the reference to MB.LW_MONITOR group
ReferenceDescription found=util.getGroupReference(groupName);
List itemList = this.client.getAddressSpace().browse(client.getNamespaceTable().toNodeId(found.getNodeId()));
// create a subscription instance for entire group
Subscription subscription =new Subscription();
for(ReferenceDescription rd:itemList){
NodeId nd=client.getNamespaceTable().toNodeId(rd.getNodeId());
MonitoredDataItem mi=new MonitoredDataItem(nd, Attributes.Value, MonitoringMode.Reporting);
mi.addChangeListener(cacheListener); // cacheListener is my MonitoredDataItemListener instance…
subscription.addItem(mi);
}
// add subscription to the client
client.addSubscription(subscription);

thanks