milo:Bad_SessionIdInvalid, The session id is not valid - opc-ua

Question

I am getting a "The session id is not valid." exception when reading the value of a node ,but just sometimes,I konw the session is not timeout,so why?
the exception ：
java.util.concurrent.ExecutionException: UaServiceFaultException: status=Bad_SessionIdInvalid, message=The session id is not valid.
at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:395)
at java.base/java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1999)
at com.ggnykj.smartems.cloud.server.autocontrol.client.OpcClientServer.readNode(OpcClientServer.java:230)
at com.ggnykj.smartems.cloud.server.autocontrol.controller.OpcClientServerController.readNode(OpcClientServerController.java:115)
at com.ggnykj.smartems.cloud.server.autocontrol.server.SaveExOpcData.run(SaveExOpcData.java:59)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: UaServiceFaultException: status=Bad_SessionIdInvalid, message=The session id is not valid.
at org.eclipse.milo.opcua.stack.client.UaTcpStackClient.lambda$receiveResponse$16(UaTcpStackClient.java:367)
at org.eclipse.milo.opcua.stack.core.util.ExecutionQueue$PollAndExecute.run(ExecutionQueue.java:107)
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515)
at java.base/java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:264)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java)
... 3 more
Exception in thread "pool-2-thread-2" java.lang.NullPointerException
at com.ggnykj.smartems.cloud.server.autocontrol.controller.OpcClientServerController.readNode(OpcClientServerController.java:116)
at com.ggnykj.smartems.cloud.server.autocontrol.server.SaveExOpcData.run(SaveExOpcData.java:59)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
at java.base/java.lang.Thread.run(Thread.java:834)
there is my code:
MyX509IdentityProvider x509IdentityProvider = new MyX509IdentityProvider(clientOption.opcServer.getCertFilePath(),
clientOption.opcServer.getPrivateKeyPath());
X509Certificate cert = x509IdentityProvider.getCertificate();
KeyPair keyPair = new KeyPair(cert.getPublicKey(), x509IdentityProvider.getPrivateKey());
OpcUaClientConfig config = OpcUaClientConfig.builder()
.setApplicationName(LocalizedText.english(clientOption.opcServer.getOpcServerName()))
//.setApplicationUri("urn:eclipse:milo:examples:client")
.setApplicationUri("")
//.setCertificate(loader.getClientCertificate())
//.setKeyPair(loader.getClientKeyPair())
.setCertificate(cert)
.setKeyPair(keyPair)
.setEndpoint(endpoint)
.setIdentityProvider(clientOption.getIdentityProvider())
.setChannelLifetime(uint(600000000))
.setSessionTimeout(uint(600000000))
//.setRequestTimeout(uint(5000))
.build();
return new OpcUaClient(config);
there is the connect and read code:
private OpcUaClient getOpcClient(OpcServer opcServer){
OpcUaClient client = null;
if(null!=opcClientMap.get(opcServer.getOpcServerId())){
client = opcClientMap.get(opcServer.getOpcServerId());
}else{
try {
ClientOption clientOption = new ClientOption(opcServer);
client = new ClientOptionRunner(clientOption).createClient();
}catch (Throwable t){
logger.error("Error getting client: {}", t.getMessage(), t);
}
opcClientMap.put(opcServer.getOpcServerId(),client);
}
return client;
}
public DataValue readNode(OpcServer opcServer,NodeId nodeId){
OpcUaClient client = getOpcClient(opcServer);
DataValue value = null;
try {
client.connect().get();
value = client.readValue(0.0, TimestampsToReturn.Both, nodeId).get();
}catch (Exception e){
e.printStackTrace();
}
return value;
}
when I read the node,there is the problem:
value = client.readValue(0.0, TimestampsToReturn.Both, nodeId).get();
but I don't know why

Answer 1

This StatusCode comes from the server.
Maybe you can capture this behavior on Wireshark to ensure you're really using the same OpcUaClient instance you think you are and not one that has had its session timeout somehow. Or maybe the capture will show the server is at fault and returning this StatusCode when you read on a freshly created Session.