问题
I'm trying to connect to a Message Hub Service. I can connect if I use the REST API but when I try to connect from my Java program there's always a timeout
I'm using the next configuration:
Properties producerProps = new Properties();
producerProps.put(SslConfigs.SSL_PROTOCOL_CONFIG, "TLSv1.2");
producerProps.put(SslConfigs.SSL_ENABLED_PROTOCOLS_CONFIG, "TLSv1.2");
producerProps.put(SslConfigs.SSL_TRUSTSTORE_LOCATION_CONFIG, "/Library/Java/JavaVirtualMachines/jdk1.8.0_66.jdk/Contents/Home/jre/lib/security/cacerts");
producerProps.put(SslConfigs.SSL_TRUSTSTORE_PASSWORD_CONFIG, "changeit");
producerProps.put(SslConfigs.SSL_TRUSTSTORE_TYPE_CONFIG, "JKS");
producerProps.put(SslConfigs.SSL_ENDPOINT_IDENTIFICATION_ALGORITHM_CONFIG, "HTTPS");
producerProps.put(CommonClientConfigs.SECURITY_PROTOCOL_CONFIG, "SSL");
producerProps.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, org.apache.kafka.common.serialization.ByteArraySerializer.class);
producerProps.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, org.apache.kafka.common.serialization.ByteArraySerializer.class);
producerProps.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "kafka01-prod01.messagehub.services.us-south.bluemix.net:9093,kafka02-prod01.messagehub.services.us-south.bluemix.net:9093,kafka03-prod01.messagehub.services.us-south.bluemix.net:9093,kafka04-prod01.messagehub.services.us-south.bluemix.net:9093,kafka05-prod01.messagehub.services.us-south.bluemix.net:9093");
producerProps.put(ProducerConfig.CLIENT_ID_CONFIG, "myApiKey");
KafkaProducer<byte[], byte[]> kafkaProducer = new KafkaProducer<>(producerProps);
ProducerRecord<byte[], byte[]> producerRecord = new ProducerRecord<>("myTopic", "records".getBytes(), "[{ \"value\" : \"test\" }]".getBytes());
RecordMetadata metadata = kafkaProducer.send(producerRecord).get();
System.out.println("Offset: " + metadata.offset());
kafkaProducer.close();
After a while the error is
Exception in thread "main" java.util.concurrent.ExecutionException: org.apache.kafka.common.errors.TimeoutException: Failed to update metadata after 231 ms.
at org.apache.kafka.clients.producer.KafkaProducer$FutureFailure.<init>(KafkaProducer.java:706)
at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:453)
at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:339)
I'm using kafka-clients version 0.9.0.0
Any thoughts?
回答1:
The exception you see is typically a symptom of the topic not having been created before use. Message Hub does not allow auto-creation of topics - they must be created either through the Bluemix Dashboard or programatically via the admin REST interface. When you got this error, had you created the topic first?
In case you hadn't found them already - here's a link to our samples, including a Java sample that creates a topic and then uses the Kafka Java client to produce/consume messages. https://github.com/ibm-messaging/message-hub-samples
回答2:
Good news. Everything works now. It turns that the topic disappeared since the last time I used it
I did a POST request to the REST API to ensure that the topic was created and instead of receiving a 422 I received a 202 so the topic wasn't created. Now everything works like a charm
Thanks to everybody
回答3:
about the UI being stuck on "Waiting for data..." we're aware of the problem and working to fix it. cheers
来源：https://stackoverflow.com/questions/34074912/timeout-connecting-to-message-hub-on-bluemix