Develop Reference

Spring boot Cron is not working from the second day

I am trying to run the server locally which has Spring boot cron expression. For the first day cron is working fine but from the next cron expression is not getting triggered.
#Component
public class MailScheduler {
#Scheduled(cron = "0 0 9 ? * *")
public void sendMail(){
System.out.println("*****************Mail Started");
}
}
I have added #EnableScheduling in main class. First day everything looks good but from second it is not working. If I restart the server on that particular day cron is getting triggered but from second day not getting triggered.
Second day Logs:
2021-05-18 12:00:00.012 INFO 20520 --- [nio-9000-exec-2] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring
DispatcherServlet 'dispatcherServlet' 2021-05-18 12:00:00.012 INFO
20520 --- [nio-9000-exec-2] o.s.web.servlet.DispatcherServlet :
Initializing Servlet 'dispatcherServlet' 2021-05-18 12:00:00.014 INFO
20520 --- [nio-9000-exec-2] o.s.web.servlet.DispatcherServlet :
Completed initialization in 2 ms 2021-05-18 14:06:39.148 WARN 20520
--- [l-1 housekeeper] com.zaxxer.hikari.pool.HikariPool : HikariPool-1 - Thread starvation or clock leap detected (housekeeper
delta=17m20s769ms350µs701ns). 2021-05-18 21:19:58.233 WARN 20520 ---
[l-1 housekeeper] com.zaxxer.hikari.pool.HikariPool :
HikariPool-1 - Thread starvation or clock leap detected (housekeeper
delta=31m42s577ms997µs900ns). 2021-05-19 07:20:11.126 WARN 20520 ---
[l-1 housekeeper] com.zaxxer.hikari.pool.HikariPool :
HikariPool-1 - Thread starvation or clock leap detected (housekeeper
delta=7h11m45s224ms352µs500ns). 2021-05-19 08:17:11.121 WARN 20520
--- [l-1 housekeeper] com.zaxxer.hikari.pool.HikariPool : HikariPool-1 - Thread starvation or clock leap detected (housekeeper
delta=5m29s194ms358µs100ns).

Hi Please check example
#Scheduled(cron = "0 0 0 * * *",zone = "Indian/Maldives")

Your schedule thread may be hanged or blocked by some consuming-time service. You should first find the blocked code with proper timeout and config a thread pool for the schedule.

java.io.IOException: Connection was aborted by the software in your host machine with Sendkey() in selenium java

OS: Win7 64bit
Browser:Chrome
I'm working on my assignment to test a program with selenium.
I'm using the code provided by the professor,which creates a web-app on my localhost:8080 (So there shouldn't be any connection problem)
public void canConenctTwoPlayers() {
// connect
//2: missing code
this.indexPage.connect.click();
assertThat(this.indexPage.hasText("Successfully connected to the game with unique "), is(true));
this.indexPage.numberPlayers.click();
this.indexPage.numberPlayers.sendKeys("2");
this.indexPage.open.click();
//second connect
ChromeDriver second_player = quickConnectAnotherUser();
//3: missing code
assertThat(this.indexPage.hasText("The game is now ready to begin"), is(true));
// quit
//4: missing code
disconnectSecondUser(second_player);
this.indexPage.disconnect.click();
}
In here numberPlayers is the element in the window, where as it name says, input the number of players. But when i use sendKeys, it gives me this exception
java.io.IOException: java.util.concurrent.ExecutionException:
java.io.IOException: Connection was aborted by the software in your host machine
And when i comment out the sendkeys, the code works well.
2018-11-30 13:24:52.749 INFO 18632 --- [nio-8080-exec-1] c.c.poker.game.PokerSocketHandler : Opened new session for _fc6yznc.
2018-11-30 13:24:52.749 INFO 18632 --- [nio-8080-exec-1] ca.carleton.poker.game.PokerGame : Player is trying to connect _fc6yznc, WebSocketServerSockJsSession[id=_fc6yznc]
2018-11-30 13:24:52.749 INFO 18632 --- [nio-8080-exec-1] ca.carleton.poker.game.PokerGame : Setting first player as admin:_fc6yznc.
2018-11-30 13:24:52.749 INFO 18632 --- [nio-8080-exec-1] ca.carleton.poker.game.PokerGame : Player is being added _fc6yznc, WebSocketServerSockJsSession[id=_fc6yznc]
2018-11-30 13:24:52.750 INFO 18632 --- [nio-8080-exec-1] ca.carleton.poker.game.PokerGame : Sessions WebSocketServerSockJsSession[id=_fc6yznc]
2018-11-30 13:24:52.750 INFO 18632 --- [nio-8080-exec-1] c.c.poker.game.PokerSocketHandler : Sending admin message to player.
2018-11-30 13:24:52.750 INFO 18632 --- [nio-8080-exec-1] ca.carleton.poker.game.PokerGame : Current number of players is 1. Required number is 4.
2018-11-30 13:24:52.872 ERROR 18632 --- [nio-8080-exec-2] c.c.poker.game.PokerSocketHandler : TRANSPORT ERROR - Error with the network.
java.io.IOException: java.util.concurrent.ExecutionException: java.io.IOException: Connection was aborted by the software in your host machine
at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessageBlock(WsRemoteEndpointImplBase.java:282)
at org.apache.tomcat.websocket.WsSession.sendCloseMessage(WsSession.java:570)
at org.apache.tomcat.websocket.WsSession.onClose(WsSession.java:510)
at org.apache.tomcat.websocket.WsFrameBase.processDataControl(WsFrameBase.java:342)
at org.apache.tomcat.websocket.WsFrameBase.processData(WsFrameBase.java:284)
at org.apache.tomcat.websocket.WsFrameBase.processInputBuffer(WsFrameBase.java:130)
at org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:60)
at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onDataAvailable(WsHttpUpgradeHandler.java:203)
at org.apache.coyote.http11.upgrade.AbstractServletInputStream.onDataAvailable(AbstractServletInputStream.java:198)
at org.apache.coyote.http11.upgrade.AbstractProcessor.upgradeDispatch(AbstractProcessor.java:96)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:663)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1521)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1478)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: java.util.concurrent.ExecutionException: java.io.IOException: Connection was aborted by the software in your host machine
at org.apache.tomcat.websocket.FutureToSendHandler.get(FutureToSendHandler.java:102)
at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessageBlock(WsRemoteEndpointImplBase.java:275)
... 16 common frames omitted
Caused by: java.io.IOException: Connection was aborted by the software in your host machine
at sun.nio.ch.SocketDispatcher.write0(Native Method)
at sun.nio.ch.SocketDispatcher.write(Unknown Source)
at sun.nio.ch.IOUtil.writeFromNativeBuffer(Unknown Source)
at sun.nio.ch.IOUtil.write(Unknown Source)
at sun.nio.ch.SocketChannelImpl.write(Unknown Source)
at org.apache.tomcat.util.net.NioChannel.write(NioChannel.java:127)
at org.apache.tomcat.util.net.NioSelectorPool.write(NioSelectorPool.java:184)
at org.apache.coyote.http11.upgrade.NioServletOutputStream.doWriteInternal(NioServletOutputStream.java:94)
at org.apache.coyote.http11.upgrade.NioServletOutputStream.doWrite(NioServletOutputStream.java:61)
at org.apache.coyote.http11.upgrade.AbstractServletOutputStream.writeInternal(AbstractServletOutputStream.java:165)
at org.apache.coyote.http11.upgrade.AbstractServletOutputStream.write(AbstractServletOutputStream.java:132)
at org.apache.tomcat.websocket.server.WsRemoteEndpointImplServer.onWritePossible(WsRemoteEndpointImplServer.java:98)
at org.apache.tomcat.websocket.server.WsRemoteEndpointImplServer.doWrite(WsRemoteEndpointImplServer.java:80)
at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.writeMessagePart(WsRemoteEndpointImplBase.java:450)
at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessage(WsRemoteEndpointImplBase.java:338)
at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessageBlock(WsRemoteEndpointImplBase.java:270)
... 16 common frames omitted
2018-11-30 13:24:52.872 INFO 18632 --- [nio-8080-exec-2] c.c.poker.game.PokerSocketHandler : Closing session for _fc6yznc with status CloseStatus[code=1000, reason=null].
2018-11-30 13:24:52.872 INFO 18632 --- [nio-8080-exec-2] c.c.poker.game.PokerSocketHandler : Disabling all accounts because the admin left.
2018-11-30 13:24:52.873 INFO 18632 --- [nio-8080-exec-2] ca.carleton.poker.game.PokerGame : Sessions WebSocketServerSockJsSession[id=_fc6yznc]
2018-11-30 13:24:52.873 INFO 18632 --- [nio-8080-exec-2] c.carleton.poker.session.SessionHandler : Registered _fc6yznc for disconnect.

This error message...
java.io.IOException: java.util.concurrent.ExecutionException:
java.io.IOException: Connection was aborted by the software in your host machine
...implies that the exception was raised due to concurrent execution.
As per the discussion ConnectionAbortedError: [WinError 10053] An established connection was aborted by the software in your host machine with GeckoDriver and Firefox this issue is observed when you attempt to invoke sendKeys() when a JavaScript / jQuery was still active.
Solution
The solution will be to induce WebDriverWait for the JavaScript / jQuery to complete using either of the ExpectedConditions:
elementToBeClickable(By locator): An expectation for checking an element is visible and enabled such that you can click it.
elementToBeClickable(WebElement element): An expectation for checking an element is visible and enabled such that you can click it.

Spring cloud stream / Kafka exceptions

I have problems with a service which uses spring cloud stream and kafka. The service had been working ok, but yesterday started reporting a series of exceptions on startup:
Checking for rethrow: count=2
2018-09-11 10:43:34.904 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] o.s.retry.support.RetryTemplate : Retry: count=2
2018-09-11 10:43:34.904 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] o.s.integration.channel.DirectChannel : preSend on channel 'payment-reply', message: GenericMessage [payload=byte[1478], headers={errorChannel=e61450f9-fa47-446f-95ae-5021868cadfa:602, deliveryAttempt=3, X-B3-ParentSpanId=a9fe9b1c87b14698, kafka_timestampType=CREATE_TIME, kafka_receivedMessageKey=null, kafka_receivedTopic=paymentResponse, spanTraceId=966a10371583367f, spanId=7aa71302bc18bb4c, spanParentSpanId=a9fe9b1c87b14698, replyChannel=e61450f9-fa47-446f-95ae-5021868cadfa:601, nativeHeaders={spanTraceId=[966a10371583367f], spanId=[7aa71302bc18bb4c], spanParentSpanId=[a9fe9b1c87b14698], spanSampled=[0]}, kafka_offset=2299, X-B3-SpanId=7aa71302bc18bb4c, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer#2fb81502, X-B3-Sampled=0, X-B3-TraceId=966a10371583367f, spanSampled=0, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTimestamp=1536592853999}]
2018-09-11 10:43:34.904 DEBUG [payment-gateway,966a10371583367f,c94b21ccaaed668b,false] 1 --- [container-0-C-1] o.s.c.s.i.m.TracingChannelInterceptor : Created a new span in pre sendNoopSpan{context=966a10371583367f/c94b21ccaaed668b}
2018-09-11 10:43:34.905 DEBUG [payment-gateway,966a10371583367f,4476713d70434d52,false] 1 --- [container-0-C-1] o.s.c.s.i.m.TracingChannelInterceptor : Created a new span in before handleNoopSpan{context=966a10371583367f/e1d1a2a6b9ad093e}
2018-09-11 10:43:34.905 DEBUG [payment-gateway,966a10371583367f,4476713d70434d52,false] 1 --- [container-0-C-1] o.s.c.s.i.m.TracingChannelInterceptor : Will finish the current span after message handled NoopSpan{context=966a10371583367f/4476713d70434d52}
2018-09-11 10:43:34.905 DEBUG [payment-gateway,966a10371583367f,c94b21ccaaed668b,false] 1 --- [container-0-C-1] o.s.c.s.i.m.TracingChannelInterceptor : Will finish the current span after completion NoopSpan{context=966a10371583367f/c94b21ccaaed668b}
2018-09-11 10:43:34.905 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] essageListenerContainer$ListenerConsumer : Received: 0 records
2018-09-11 10:43:35.001 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] essageListenerContainer$ListenerConsumer : Commit list: {}
2018-09-11 10:43:35.002 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] o.a.k.c.consumer.internals.Fetcher : [Consumer clientId=consumer-2, groupId=payment-gateway] Fetch READ_UNCOMMITTED at offset 0 for partition refundResponse-0 returned fetch data (error=NONE, highWaterMark=0, lastStableOffset = -1, logStartOffset = 0, abortedTransactions = null, recordsSizeInBytes=0)
2018-09-11 10:43:35.002 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] o.a.k.c.consumer.internals.Fetcher : [Consumer clientId=consumer-2, groupId=payment-gateway] Added READ_UNCOMMITTED fetch request for partition refundResponse-0 at offset 0 to node 10.244.0.194:9092 (id: 2 rack: null)
2018-09-11 10:43:35.002 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] o.a.k.c.consumer.internals.Fetcher : [Consumer clientId=consumer-2, groupId=payment-gateway] Sending READ_UNCOMMITTED fetch for partitions [refundResponse-0] to broker 10.244.0.194:9092 (id: 2 rack: null)
2018-09-11 10:43:35.003 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] o.s.retry.support.RetryTemplate : Checking for rethrow: count=3
2018-09-11 10:43:35.003 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] o.s.retry.support.RetryTemplate : Retry failed last attempt: count=3
2018-09-11 10:43:35.004 DEBUG [payment-gateway,,,] 1 --- [container-0-C-1] o.s.i.h.a.ErrorMessageSendingRecoverer : Sending ErrorMessage: failedMessage: GenericMessage [payload=byte[1478], headers={errorChannel=e61450f9-fa47-446f-95ae-5021868cadfa:602, deliveryAttempt=3, X-B3-ParentSpanId=7aa71302bc18bb4c, kafka_timestampType=CREATE_TIME, kafka_receivedTopic=paymentResponse, spanTraceId=966a10371583367f, spanId=c94b21ccaaed668b, spanParentSpanId=7aa71302bc18bb4c, replyChannel=e61450f9-fa47-446f-95ae-5021868cadfa:601, nativeHeaders={spanTraceId=[966a10371583367f], spanId=[c94b21ccaaed668b], spanParentSpanId=[7aa71302bc18bb4c], spanSampled=[0]}, kafka_offset=2299, X-B3-SpanId=c94b21ccaaed668b, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer#2fb81502, X-B3-Sampled=0, X-B3-TraceId=966a10371583367f, id=83994228-ba45-2303-1f7e-2eaf8f49c400, spanSampled=0, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTimestamp=1536592853999, timestamp=1536662614904}]
2018-09-11 08:44:19.837 ERROR [payment-gateway,bd9888a7d590ebf7,535db983ae0aedab,false] 1 --- [container-0-C-1] o.s.integration.handler.LoggingHandler :
org.springframework.messaging.MessageDeliveryException:
Dispatcher has no subscribers for channel 'application-1.payment-reply'.; nested exception is org.springframework.integration.MessageDispatchingException:
Dispatcher has no subscribers, failedMessage=GenericMessage [payload=byte[1197], headers={errorChannel=e61450f9-fa47-446f-95ae-5021868cadfa:426, deliveryAttempt=3, X-B3-ParentSpanId=760139e0bc5d9ac0, kafka_timestampType=CREATE_TIME, kafka_receivedTopic=paymentResponse, spanTraceId=bd9888a7d590ebf7, spanId=5c6ac2c521faf6e7, spanParentSpanId=760139e0bc5d9ac0, replyChannel=e61450f9-fa47-446f-95ae-5021868cadfa:425, nativeHeaders={spanTraceId=[bd9888a7d590ebf7], spanId=[535db983ae0aedab], spanParentSpanId=[5c6ac2c521faf6e7], spanSampled=[0], X-B3-TraceId=[bd9888a7d590ebf7], X-B3-SpanId=[535db983ae0aedab], X-B3-ParentSpanId=[5c6ac2c521faf6e7], X-B3-Sampled=[0]}, kafka_offset=2258, X-B3-SpanId=5c6ac2c521faf6e7, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer#59715a4a, X-B3-Sampled=0, X-B3-TraceId=bd9888a7d590ebf7, id=88531659-3fb0-a59f-bb69-54c9ba82d608, spanSampled=0, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTimestamp=1536592840192, timestamp=1536655459828}], failedMessage=GenericMessage [payload=byte[1197], headers={errorChannel=e61450f9-fa47-446f-95ae-5021868cadfa:426, deliveryAttempt=3, X-B3-ParentSpanId=760139e0bc5d9ac0, kafka_timestampType=CREATE_TIME, kafka_receivedTopic=paymentResponse, spanTraceId=bd9888a7d590ebf7, spanId=5c6ac2c521faf6e7, spanParentSpanId=760139e0bc5d9ac0, replyChannel=e61450f9-fa47-446f-95ae-5021868cadfa:425, nativeHeaders={spanTraceId=[bd9888a7d590ebf7], spanId=[535db983ae0aedab], spanParentSpanId=[5c6ac2c521faf6e7], spanSampled=[0], X-B3-TraceId=[bd9888a7d590ebf7], X-B3-SpanId=[535db983ae0aedab], X-B3-ParentSpanId=[5c6ac2c521faf6e7], X-B3-Sampled=[0]}, kafka_offset=2258, X-B3-SpanId=5c6ac2c521faf6e7, scst_nativeHeadersPresent=true, kafka_consumer=org.apache.kafka.clients.consumer.KafkaConsumer#59715a4a, X-B3-Sampled=0, X-B3-TraceId=bd9888a7d590ebf7, id=88531659-3fb0-a59f-bb69-54c9ba82d608, spanSampled=0, kafka_receivedPartitionId=0, contentType=application/json, kafka_receivedTimestamp=1536592840192, timestamp=1536655459828}]
at org.springframework.integration.channel.AbstractSubscribableChannel.doSend(AbstractSubscribableChannel.java:77)
after some time we then see exceptions like this:
Caused by: org.springframework.messaging.core.DestinationResolutionException: failed to look up MessageChannel with name '946859a6-bc27-466d-91ba-3da93af50ac9:1' in the BeanFactory.; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named '946859a6-bc27-466d-91ba-3da93af50ac9:1' available
the connection to kafka is configured with a property: spring.kafka.bootstrap-server = kafka.kafka:9092
and the topics are configured with spring cloud stream properties: spring.cloud.stream.bindings.[topic-name].destination = blah
The interaction with kafka goes via spring integration with code like this:
#MessagingGateway
public interface StreamGateway {
#Gateway(requestChannel = KafkaConfig.ENRICH_PAYMENT, replyChannel = ChannelNames.PAYMENT_REPLY, replyTimeout = 10000)
String processPayment(String payload);
}
//Different class:
private final StreamGateway gateway;
...
gateway.processPayment(message)
This is running on an azure kubernetes deployment, and kafka is in a separate pod from the spring boot service.
thanks in advance.
Update:
The problem reoccured and some further investigation has highlighted a couple of things
Because we're using spring integration #MessagingGateway and #Gateway to create a synchronous interaction with Kafka, there is no normal topic StreamListener or subscriber
The problem is occurring when there is a lag on the topic, i.e. there are messages in the topic beyond the topic offset.
The lack of a normal StreamListener means the lag messages have no means of being processed. Only when a connection is made by the MessageGateway, is it possible for messages to be read from the topic.
One means of getting rid of the problem is to read all 'lag' messages, so that the lag is 0. The service will then start normally, however if I manually post messages to the topic (out-with the MessageGateway interaction), then the error reoccurs.
A second partial solution (which I dont fully understand yet) is to add a #DependsOn annotation to the MessageGateway, indicating that it requires a bean separately created with a #Input SubscribableChannel object. This means the SubscribableChannel must be created before the MessageGateway, therefore creating a Subscriber, however there is still no StreamListener, so exceptions are still thrown as lag messages are pulled from the topic, with no-where to go 🤨

While I am not sure about the details of your application, what is clear is that a Message gets delivered to an application-1.payment-reply channel which, as the error states, has no subscriber. Basically it means there is no listener on that channel (such as #StreamListener or #ServiceActivator etc).
It is a very common Spring Integration miss-configuration, but without looking at your app it is hard to say where it is.

On looking at the debug log I noticed that the service was connecting to other topics correctly, but having problems with the payment-reply topic. I tried deleting this topic and restarting the service. This fixed the problem.

Eclipse milo: Session closed when trying to read data

I have an external OPC UA server, from which I would like to read data. I use username and password authentication, so my client is initialized like follows:
public class MyClient {
// ...
public MyClient() throws Exception {
EndpointDescription[] endpoints =
UaTcpStackClient.getEndpoints(OPCConstants.OPC_SERVER_URI).get();
// using the first endpoint
EndpointDescription endpoint = endpoints[0];
// client configuration
OpcUaClientConfig config = OpcUaClientConfig.builder()
.setApplicationName(LocalizedText.english("Example Client"))
.setApplicationUri(String.format("some:example-client:%s",
UUID.randomUUID()))
.setIdentityProvider(new UsernameProvider(USERNAME, PWD))
.setEndpoint(endpoint)
.build();
}
}
The client's request is the following:
public CompletableFuture<DataValue> getData(NodeId nodeId) {
LOGGER.debug("Sending request");
return client.readValue(60000000.0, TimestampsToReturn.Server, nodeId);
}
I call this request from the main method after initializing the client and connecting it to the server:
MyClient client = new MyClient();
NodeId requestedData = new NodeId(DATA_ID, DATA_KEY);
LOGGER.info("Sending synchronous TestStackRequest NodeId={}",
requestedData);
client.connect();
DataValue response = client.getData(requestedData).get();
LOGGER.info("Received response value={}", response.getValue());
client.disconnect();
However, this code doesn't work (the session is closed when trying to read informations from the server). I get the following output:
2018-04-12 17:43:27,765 DEBUG --- [ua-netty-event-loop-0] Recycler : -Dio.netty.recycler.maxCapacity.default: 262144
2018-04-12 17:43:27,777 DEBUG --- [ua-netty-event-loop-0] UaTcpClientAcknowledgeHandler : Sent Hello message on channel=[id: 0xfd9519e3, L:/172.20.100.54:55805 - R:/172.20.100.135:4840].
2018-04-12 17:43:27,786 DEBUG --- [ua-netty-event-loop-0] UaTcpClientAcknowledgeHandler : Received Acknowledge message on channel=[id: 0xfd9519e3, L:/172.20.100.54:55805 - R:/172.20.100.135:4840].
2018-04-12 17:43:27,793 DEBUG --- [ua-netty-event-loop-0] UaTcpClientMessageHandler : OpenSecureChannel timeout scheduled for +5s
2018-04-12 17:43:27,946 DEBUG --- [ua-shared-pool-0] UaTcpClientMessageHandler : Sent OpenSecureChannelRequest (Issue, id=0, currentToken=-1, previousToken=-1).
2018-04-12 17:43:27,951 DEBUG --- [ua-netty-event-loop-0] UaTcpClientMessageHandler : OpenSecureChannel timeout canceled
2018-04-12 17:43:27,961 DEBUG --- [ua-shared-pool-0] UaTcpClientMessageHandler : Received OpenSecureChannelResponse.
2018-04-12 17:43:27,967 DEBUG --- [ua-shared-pool-0] UaTcpClientMessageHandler : SecureChannel id=1698234671, currentTokenId=1, previousTokenId=-1, lifetime=3600000ms, createdAt=DateTime{utcTime=131680285857690000, javaDate=Thu Apr 12 19:43:05 CEST 2018}
2018-04-12 17:43:27,968 DEBUG --- [ua-netty-event-loop-0] UaTcpClientMessageHandler : 0 message(s) queued before handshake completed; sending now.
2018-04-12 17:43:27,968 DEBUG --- [ua-shared-pool-1] ClientChannelManager : Channel bootstrap succeeded: localAddress=/172.20.100.54:55805, remoteAddress=/172.20.100.135:4840
2018-04-12 17:43:27,996 DEBUG --- [ua-shared-pool-0] ClientChannelManager : disconnect(), currentState=Connected
2018-04-12 17:43:27,997 DEBUG --- [ua-shared-pool-1] ClientChannelManager : Sending CloseSecureChannelRequest...
2018-04-12 17:43:28,000 DEBUG --- [ua-netty-event-loop-0] ClientChannelManager : channelInactive(), disconnect complete
2018-04-12 17:43:28,001 DEBUG --- [ua-netty-event-loop-0] ClientChannelManager : disconnect complete, state set to Idle
2018-04-12 17:43:28,011 INFO --- [main] OpcUaClient : Eclipse Milo OPC UA Stack version: 0.2.1
2018-04-12 17:43:28,011 INFO --- [main] OpcUaClient : Eclipse Milo OPC UA Client SDK version: 0.2.1
2018-04-12 17:43:28,056 DEBUG --- [main] OpcUaClient : Added ServiceFaultListener: org.eclipse.milo.opcua.sdk.client.session.SessionFsm$FaultListener#46d59067
2018-04-12 17:43:28,066 DEBUG --- [main] OpcUaClient : Added SessionActivityListener: org.eclipse.milo.opcua.sdk.client.subscriptions.OpcUaSubscriptionManager$1#78452606
2018-04-12 17:43:28,189 INFO --- [main] CommunicationMain : Sending synchronous TestStackRequest NodeId=NodeId{ns=6, id=::opcua:opcData.outGoing.basic.cycleStep}
2018-04-12 17:43:28,189 DEBUG --- [main] ClientChannelManager : connect(), currentState=NotConnected
2018-04-12 17:43:28,190 DEBUG --- [main] ClientChannelManager : connect() while NotConnected
java.lang.Exception
at org.eclipse.milo.opcua.stack.client.ClientChannelManager.connect(ClientChannelManager.java:67)
at org.eclipse.milo.opcua.stack.client.UaTcpStackClient.connect(UaTcpStackClient.java:127)
at org.eclipse.milo.opcua.sdk.client.OpcUaClient.connect(OpcUaClient.java:313)
at com.mycompany.opcua.participants.MyClient.connect(MyClient.java:147)
at com.mycompany.opcua.participants.CommunicationMain.testClient(CommunicationMain.java:69)
at com.mycompany.opcua.participants.CommunicationMain.main(CommunicationMain.java:51)
2018-04-12 17:43:28,190 DEBUG --- [main] MyClient : Sending request
2018-04-12 17:43:28,197 DEBUG --- [ua-netty-event-loop-1] UaTcpClientAcknowledgeHandler : Sent Hello message on channel=[id: 0xd9b3f832, L:/172.20.100.54:55806 - R:/172.20.100.135:4840].
2018-04-12 17:43:28,204 DEBUG --- [ua-netty-event-loop-1] UaTcpClientAcknowledgeHandler : Received Acknowledge message on channel=[id: 0xd9b3f832, L:/172.20.100.54:55806 - R:/172.20.100.135:4840].
2018-04-12 17:43:28,205 DEBUG --- [ua-netty-event-loop-1] UaTcpClientMessageHandler : OpenSecureChannel timeout scheduled for +5s
2018-04-12 17:43:28,205 DEBUG --- [ua-shared-pool-0] UaTcpClientMessageHandler : Sent OpenSecureChannelRequest (Issue, id=0, currentToken=-1, previousToken=-1).
2018-04-12 17:43:28,208 DEBUG --- [ua-netty-event-loop-1] UaTcpClientMessageHandler : OpenSecureChannel timeout canceled
2018-04-12 17:43:28,208 DEBUG --- [ua-shared-pool-0] UaTcpClientMessageHandler : Received OpenSecureChannelResponse.
2018-04-12 17:43:28,209 DEBUG --- [ua-shared-pool-0] UaTcpClientMessageHandler : SecureChannel id=1698234672, currentTokenId=1, previousTokenId=-1, lifetime=3600000ms, createdAt=DateTime{utcTime=131680285860260000, javaDate=Thu Apr 12 19:43:06 CEST 2018}
2018-04-12 17:43:28,209 DEBUG --- [ua-netty-event-loop-1] UaTcpClientMessageHandler : 0 message(s) queued before handshake completed; sending now.
2018-04-12 17:43:28,209 DEBUG --- [ua-shared-pool-1] ClientChannelManager : Channel bootstrap succeeded: localAddress=/172.20.100.54:55806, remoteAddress=/172.20.100.135:4840
2018-04-12 17:43:28,210 DEBUG --- [ua-shared-pool-0] SessionFsm : S(Inactive) x E(CreateSessionEvent) = S'(Creating)
Exception in thread "main" java.util.concurrent.ExecutionException: UaException: status=Bad_SessionClosed, message=The session was closed by the client.
at java.base/java.util.concurrent.CompletableFuture.reportGet(CompletableFuture.java:395)2018-04-12 17:43:28,212 DEBUG --- [ua-shared-pool-1] SessionFsm : Sending CreateSessionRequest...
at java.base/java.util.concurrent.CompletableFuture.get(CompletableFuture.java:1999)
at com.mycompany.opcua.participants.CommunicationMain.testClient(CommunicationMain.java:70)
at com.mycompany.opcua.participants.CommunicationMain.main(CommunicationMain.java:51)
Caused by: UaException: status=Bad_SessionClosed, message=The session was closed by the client.
at org.eclipse.milo.opcua.stack.core.util.FutureUtils.failedUaFuture(FutureUtils.java:100)
at org.eclipse.milo.opcua.stack.core.util.FutureUtils.failedUaFuture(FutureUtils.java:88)
at org.eclipse.milo.opcua.sdk.client.session.states.Inactive.(Inactive.java:28)
at org.eclipse.milo.opcua.sdk.client.session.SessionFsm.(SessionFsm.java:69)
at org.eclipse.milo.opcua.sdk.client.OpcUaClient.(OpcUaClient.java:159)2018-04-12 17:43:28,212 INFO --- [NonceUtilSecureRandom] NonceUtil : SecureRandom seeded in 0ms.
at com.mycompany.opcua.participants.MyClient.(MyClient.java:112)
at com.mycompany.opcua.participants.CommunicationMain.testClient(CommunicationMain.java:60)
... 1 more
I use Eclipse milo 0.2.1 as OPC UA library.
Could you please tell me hat can cause this issue and how to fix it? Can it be a race condition related to this?
I can connect to the same server using other client (UaExpert).
Thank you in advance.

All of the calls you're making (connect(), disconnect(), and readValues()) are asynchronous, so what's likely happening here is you're not connected when you attempt the read.
Make sure for these examples you block for the result before moving to the next step. (you're not doing this on connect())

why does spring-boot and postgres connection breaks after certain time?

I run Spring-Boot with gradle using the tomcat-connection-pool. All the standard spring-boot-tools. I run several soap-webservices on that webserver. It all works fine when testing the load of the server. But after a doing nothing for ~7.5hours this exception occurs. Sure its a timeout but I try to prevent it with the following:
spring.datasource.url=jdbc:postgresql://mydb?autoReconnect=true
I use #transactional for certain statements. But in general I only use the JPA-Repository from spring-boot.
The connections are managed by the tomcat-connection-pool so there is no idle-connection-problem.
When I restart the application-server everything runs fine again.
My Database-server runs PostgreSQL 9.4.1 on x86_64-unknown-linux-gnu and there is NO firewall between the database and the app-server.
Do I need tcp_keep alives?
Why does my connection breaks after a certain time and is no more recoverable?
My App-properties:
#
# [ Database Configuration Section ]
#
spring.jpa.database=POSTGRESQL
spring.jpa.show-sql=false
hibernate.format_sql=true
hibernate.hbm2ddl.auto=validate
spring.jpa.hibernate.naming-strategy=org.hibernate.cfg.DefaultNamingStrategy
spring.datasource.platform=postgres
spring.database.driverClassName=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://*****:5434/******
spring.datasource.username=*****
spring.datasource.password=*****
logging.file=*******.log
logging.level.=WARNING
2015-09-29 11:58:50.598 INFO 10498 --- [nio-9092-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring FrameworkServlet 'dispatcherServlet'
2015-09-29 11:58:50.598 INFO 10498 --- [nio-9092-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization started
2015-09-29 11:58:50.674 INFO 10498 --- [nio-9092-exec-1] o.s.web.servlet.DispatcherServlet : FrameworkServlet 'dispatcherServlet': initialization completed in 76 ms
2015-09-29 19:23:03.777 WARN 10498 --- [ool-3-thread-16] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 0, SQLState: 08006
2015-09-29 19:23:03.779 ERROR 10498 --- [ool-3-thread-16] o.h.engine.jdbc.spi.SqlExceptionHelper : An I/O error occurred while sending to the backend.
2015-09-29 19:23:03.785 INFO 10498 --- [ool-3-thread-16] o.h.e.j.b.internal.AbstractBatchImpl : HHH000010: On release of batch it still contained JDBC statements
2015-09-29 19:23:03.836 ERROR 10498 --- [ool-3-thread-16] o.s.orm.jpa.JpaTransactionManager : Commit exception overridden by rollback exception
java.net.SocketException: Connection timed out
at java.net.SocketInputStream.socketRead0(Native Method) ~[na:1.8.0_25]
at java.net.SocketInputStream.read(SocketInputStream.java:150) ~[na:1.8.0_25]
at java.net.SocketInputStream.read(SocketInputStream.java:121) ~[na:1.8.0_25]
at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:143) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:112) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:71) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:282) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1718) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:173) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
... 61 common frames omitted
Wrapped by: org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend.
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:201) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:615) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:465) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeUpdate(AbstractJdbc2Statement.java:411) ~[postgresql-9.4-1202-jdbc41.jar!/:9.4]
at org.hibernate.engine.jdbc.internal.ResultSetReturnImpl.executeUpdate(ResultSetReturnImpl.java:208) ~[hibernate-core-4.3.11.Final.jar!/:4.3.11.Final]
... 57 common frames omitted
Wrapped by: org.hibernate.exception.JDBCConnectionException: could not execute statement
EDIT:
I've added this and testing it currently:
spring.datasource.testOnBorrow=true
spring.datasource.validationQuery=SELECT 1
And removed autoReconnect.

As mentioned by #Yuki Yoshida the answer was that simple.
I added
spring.datasource.validation-query= select 1
spring.datasource.test-on-borrow=true
to my configuration and it works.
Test-on-borrow:
testOnBorrow: Default: true
The indication of whether objects will be validated
before being borrowed from the pool. If the object fails to validate,
it will be dropped from the pool, and we will attempt to borrow
another.
And
validationQuery: Default: for most db languages select 1 else see here
validationQuery
The SQL query that will be used to validate
connections from this pool before returning them to the caller. If
specified, this query MUST be an SQL SELECT statement that returns at
least one row. If not specified, connections will be validation by
calling the isValid() method.
I actually tried this already but I did not explicitly set test-on-borrow to true because of its default. Looks like you have to set it explicitly.