We develop an internal company framework on top of Spring Boot and we'd like to support Kafka-Streams with Spring Cloud Stream. We need to automagically inject some headers to all outbound messages. We've achieved this with standard Spring Cloud Stream Kafka Binder registering a custom ChannelInterceptor, but this is not working for Kafka Streams, as they seem to follow a different path.
Is there any equivalent to ChannelInterceptor for Spring Cloud Stream Kafka Streams binder?
I found this customizer/configurer:
#Bean
public StreamsBuilderFactoryBeanConfigurer streamsBuilderFactoryBeanConfigurer() {
return factoryBean -> {
factoryBean.setInfrastructureCustomizer(new KafkaStreamsInfrastructureCustomizer() {
#Override
public void configureBuilder(final StreamsBuilder builder) {
}
#Override
public void configureTopology(final Topology topology) {
}
});
factoryBean.setKafkaStreamsCustomizer(new KafkaStreamsCustomizer() {
#Override
public void customize(final KafkaStreams kafkaStreams) {
}
});
};
}
My last idea was to use the configureTopology method to automagically modify the Topology and insert a Transformer just before the last sink node, but in order to add this new node I have to specify the parent node, so I would need to know the name of last sink node and maybe all node names were generated automatically by Kafka Streams... The only way is to use topology.describe() method and maybe parse the String output... This sounds too complicated compared to a simple ChannelInterceptor.
Any ideas?
You could add a ProducerInterceptor to the streams config.
/**
* A plugin interface that allows you to intercept (and possibly mutate) the records received by the producer before
* they are published to the Kafka cluster.
* <p>
* This class will get producer config properties via <code>configure()</code> method, including clientId assigned
* by KafkaProducer if not specified in the producer config. The interceptor implementation needs to be aware that it will be
* sharing producer config namespace with other interceptors and serializers, and ensure that there are no conflicts.
* <p>
* Exceptions thrown by ProducerInterceptor methods will be caught, logged, but not propagated further. As a result, if
* the user configures the interceptor with the wrong key and value type parameters, the producer will not throw an exception,
* just log the errors.
* <p>
* ProducerInterceptor callbacks may be called from multiple threads. Interceptor implementation must ensure thread-safety, if needed.
* <p>
* Implement {#link org.apache.kafka.common.ClusterResourceListener} to receive cluster metadata once it's available. Please see the class documentation for ClusterResourceListener for more information.
*/
public interface ProducerInterceptor<K, V> extends Configurable {
You can modify the record's headers there.
(You can use this technique for the message channel binder too, instead of a ChannelInterceptor).
Related
My application is listening to multiple kafka topics. Right now, my listener looks like below, and my.topics in property file contains the list of comma separated kafka topics
#KafkaListener(topics = ["#{'\${my.topics}'.split(',')}"], groupId = "my.group", containerFactory = "myKafkaFactory")
fun genericMessageListener(myRequest: MyRequest, ack: Acknowledgment) {
//do Something with myRequest
ack.acknowledge()
}
My ConcurrentKafkaListenerContainerFactory is
#Bean
fun myKafkaFactory(): ConcurrentKafkaListenerContainerFactory<String, MyRequest> {
val factory = ConcurrentKafkaListenerContainerFactory<String, MyRequest>()
factory.consumerFactory = DefaultKafkaConsumerFactory(configProps(), StringDeserializer(), MyRequestDeserializer())
factory.containerProperties.ackMode = ContainerProperties.AckMode.MANUAL
return factory
}
Is there a way i can create a separate consumer for each topic dynamically so that when I add one more topic to the list in my.topics, spring will automatically creates a separate consumer for that topic.
The problem I am facing now is, if something goes wrong with one of the messages in any of the topics, messages in other topics are also getting impacted.
On a high level, i am looking for something like this
#Bean
fun myKafkaFactory(): ConcurrentKafkaListenerContainerFactory<String, MyRequest> {
val factory = ConcurrentKafkaListenerContainerFactory<String, MyRequest>()
factory.consumerFactory = DefaultKafkaConsumerFactory(configProps(), StringDeserializer(), MyRequestDeserializer())
factory.containerProperties.ackMode = ContainerProperties.AckMode.MANUAL
factory.isOneConsumerPerTopic(true)
return factory
}
so that factory.isOneConsumerPerTopic(true) will ensure a separate consumer is created for each topic in the Array.
I did go through How to create separate Kafka listener for each topic dynamically in springboot?. I am looking a bit more 'cleaner' solution. :)
You can add a custom PartitionAssignor to the Kafka consumer configuration.
Set the container concurrency to (at least) the number of topics and have your assignor assign the partitions for each topic to a specific consumer(s).
/**
* This interface is used to define custom partition assignment for use in
* {#link org.apache.kafka.clients.consumer.KafkaConsumer}. Members of the consumer group subscribe
* to the topics they are interested in and forward their subscriptions to a Kafka broker serving
* as the group coordinator. The coordinator selects one member to perform the group assignment and
* propagates the subscriptions of all members to it. Then {#link #assign(Cluster, Map)} is called
* to perform the assignment and the results are forwarded back to each respective members
*
* In some cases, it is useful to forward additional metadata to the assignor in order to make
* assignment decisions. For this, you can override {#link #subscription(Set)} and provide custom
* userData in the returned Subscription. For example, to have a rack-aware assignor, an implementation
* can use this user data to forward the rackId belonging to each member.
*/
public interface PartitionAssignor {
You could start with the AbstractPartitionAssignor.
See the spring-kafka documentation.
When listening to multiple topics, the default partition distribution may not be what you expect. For example, ...
I'm trying to setup a project with Springboot cloud Stream with Kafka. I managed to build a simple example, where a listener gets messages from a topic and after processed it, it sends the output to another topic.
My listener and channels are configured like this:
#Component
public class FileEventListener {
private FileEventProcessorService fileEventProcessorService;
#Autowired
public FileEventListener(FileEventProcessorService fileEventProcessorService) {
this.fileEventProcessorService = fileEventProcessorService;
}
#StreamListener(target = FileEventStreams.INPUT)
public void handleLine(#Payload(required = false) String jsonData) {
this.fileEventProcessorService.process(jsonData);
}
}
public interface FileEventStreams {
String INPUT = "file_events";
String OUTPUT = "raw_lines";
#Input(INPUT)
SubscribableChannel inboundFileEventChannel();
#Output(OUTPUT)
MessageChannel outboundRawLinesChannel();
}
The problem with this example is that when the service starts, it doesn't check for messages that already exist in the topic, it only process those messages that are sent after it started. I'm very new to Springboot stream and kafka, but for what I've read, this behavior may correspond to the fact that I'm using a SubscribableChannel. I tried to use a QueueChannel for example, to see how it works but I found the following exception:
Error creating bean with name ... nested exception is java.lang.IllegalStateException: No factory found for binding target type: org.springframework.integration.channel.QueueChannel among registered factories: channelFactory,messageSourceFactory
So, my questions are:
If I want to process all messages that exists in the topic once the application starts (and also messages are processed by only one consumer), I'm on the right path?
Even if QueueChannel is not the right choice for achieve the behavior explained in 1.) What do I have to add to my project to be able to use this type of channel?
Thanks!
Add spring.cloud.stream.bindings.file_events.group=foo
anonymous groups consume from the end of the topic only, bindings with a group consume from the beginning, by default.
You cannot use a PollableChannel for a binding, it must be a SubscribableChannel.
I am trying to understand why I would want to use Spring cloud stream with RabbitMQ. I've had a look at the RabbitMQ Spring tutorial 4 (https://www.rabbitmq.com/tutorials/tutorial-four-spring-amqp.html) which is basically what I want to do. It creates a direct exchange with 2 queues attached and depending on the routing key a message is either routed to Q1 or to Q2.
The whole process is pretty straight forward if you look at the tutorial, you create all the parts, bind them together and youre ready to go.
I was wondering what benefit I would gain in using Sing Cloud Stream and if that is even the use case for it. It was easy to create a simple exchange and even defining destination and group was straight forward with stream. So I thought why not go further and try to handle the tutorial case with stream.
I have seen that Stream has a BinderAwareChannelResolver which seems to do the same thing. But I am struggling to put it all together to achieve the same as in the RabbitMQ Spring tutorial. I am not sure if it is a dependency issue, but I seem to misunderstand something fundamentally here, I thought something like:
spring.cloud.stream.bindings.output.destination=myDestination
spring.cloud.stream.bindings.output.group=consumerGroup
spring.cloud.stream.rabbit.bindings.output.producer.routing-key-expression='key'
should to the trick.
Is there anyone with a minimal example for a source and sink which basically creates a direct exchange, binds 2 queues to it and depending on routing key routes to either one of those 2 queues like in https://www.rabbitmq.com/tutorials/tutorial-four-spring-amqp.html?
EDIT:
Below is a minimal set of code which demonstrates how to do what I asked. I did not attach the build.gradle as it is straight forward (but if anyone is interested, let me know)
application.properties: setup the producer
spring.cloud.stream.bindings.output.destination=tut.direct
spring.cloud.stream.rabbit.bindings.output.producer.exchangeType=direct
spring.cloud.stream.rabbit.bindings.output.producer.routing-key-expression=headers.type
Sources.class: setup the producers channel
public interface Sources {
String OUTPUT = "output";
#Output(Sources.OUTPUT)
MessageChannel output();
}
StatusController.class: Respond to rest calls and send message with specific routing keys
/**
* Status endpoint for the health-check service.
*/
#RestController
#EnableBinding(Sources.class)
public class StatusController {
private int index;
private int count;
private final String[] keys = {"orange", "black", "green"};
private Sources sources;
private StatusService status;
#Autowired
public StatusController(Sources sources, StatusService status) {
this.sources = sources;
this.status = status;
}
/**
* Service available, service returns "OK"'.
* #return The Status of the service.
*/
#RequestMapping("/status")
public String status() {
String status = this.status.getStatus();
StringBuilder builder = new StringBuilder("Hello to ");
if (++this.index == 3) {
this.index = 0;
}
String key = keys[this.index];
builder.append(key).append(' ');
builder.append(Integer.toString(++this.count));
String payload = builder.toString();
log.info(payload);
// add kv pair - routingkeyexpression (which matches 'type') will then evaluate
// and add the value as routing key
Message<String> msg = new GenericMessage<>(payload, Collections.singletonMap("type", key));
sources.output().send(msg);
// return rest call
return status;
}
}
consumer side of things, properties:
spring.cloud.stream.bindings.input.destination=tut.direct
spring.cloud.stream.rabbit.bindings.input.consumer.exchangeType=direct
spring.cloud.stream.rabbit.bindings.input.consumer.bindingRoutingKey=orange
spring.cloud.stream.bindings.inputer.destination=tut.direct
spring.cloud.stream.rabbit.bindings.inputer.consumer.exchangeType=direct
spring.cloud.stream.rabbit.bindings.inputer.consumer.bindingRoutingKey=black
Sinks.class:
public interface Sinks {
String INPUT = "input";
#Input(Sinks.INPUT)
SubscribableChannel input();
String INPUTER = "inputer";
#Input(Sinks.INPUTER)
SubscribableChannel inputer();
}
ReceiveStatus.class: Receive the status:
#EnableBinding(Sinks.class)
public class ReceiveStatus {
#StreamListener(Sinks.INPUT)
public void receiveStatusOrange(String msg) {
log.info("I received a message. It was orange number: {}", msg);
}
#StreamListener(Sinks.INPUTER)
public void receiveStatusBlack(String msg) {
log.info("I received a message. It was black number: {}", msg);
}
}
Spring Cloud Stream lets you develop event driven micro service applications by enabling the applications to connect (via #EnableBinding) to the external messaging systems using the Spring Cloud Stream Binder implementations (Kafka, RabbitMQ, JMS binders etc.,). Apparently, Spring Cloud Stream uses Spring AMQP for the RabbitMQ binder implementation.
The BinderAwareChannelResolver is applicable for dynamically binding support for the producers and I think in your case it is about configuring the exchanges and binding of consumers to that exchange.
For instance, you need to have 2 consumers with the appropriate bindingRoutingKey set based on your criteria and a single producer with the properties(routing-key-expression, destination) you mentioned above (except the group). I noticed that you have configured group for the outbound channel. The group property is applicable only for the consumers (hence inbound).
You might also want to check this one: https://github.com/spring-cloud/spring-cloud-stream-binder-rabbit/issues/57 as I see some discussion around using routing-key-expression. Specifically, check this one on using the expression value.
I am using Spring Cloud Stream and want to programmatically create and bind channels. My use case is that during application startup I receive the dynamic list of Kafka topics to subscribe to. How can I then create a channel for each topic?
I ran into similar scenario recently and below is my sample of creating SubscriberChannels dynamically.
ConsumerProperties consumerProperties = new ConsumerProperties();
consumerProperties.setMaxAttempts(1);
BindingProperties bindingProperties = new BindingProperties();
bindingProperties.setConsumer(consumerProperties);
bindingProperties.setDestination(retryTopic);
bindingProperties.setGroup(consumerGroup);
bindingServiceProperties.getBindings().put(consumerName, bindingProperties);
SubscribableChannel channel = (SubscribableChannel)bindingTargetFactory.createInput(consumerName);
beanFactory.registerSingleton(consumerName, channel);
channel = (SubscribableChannel)beanFactory.initializeBean(channel, consumerName);
bindingService.bindConsumer(channel, consumerName);
channel.subscribe(consumerMessageHandler);
I had to do something similar for the Camel Spring Cloud Stream component.
Perhaps the Consumer code to bind a destination "really just a String indicating the channel name" would be useful to you?
In my case I only bind a single destination, however I don't imagine it being much different conceptually for multiple destinations.
Below is the gist of it:
#Override
protected void doStart() throws Exception {
SubscribableChannel bindingTarget = createInputBindingTarget();
bindingTarget.subscribe(message -> {
// have your way with the received incoming message
});
endpoint.getBindingService().bindConsumer(bindingTarget,
endpoint.getDestination());
// at this point the binding is done
}
/**
* Create a {#link SubscribableChannel} and register in the
* {#link org.springframework.context.ApplicationContext}
*/
private SubscribableChannel createInputBindingTarget() {
SubscribableChannel channel = endpoint.getBindingTargetFactory()
.createInputChannel(endpoint.getDestination());
endpoint.getBeanFactory().registerSingleton(endpoint.getDestination(), channel);
channel = (SubscribableChannel) endpoint.getBeanFactory().initializeBean(channel,
endpoint.getDestination());
return channel;
}
See here for the full source for more context.
I had a task where I did not know the topics in advance. I solved it by having one input channel which listens to all the topics I need.
https://docs.spring.io/spring-cloud-stream/docs/Brooklyn.RELEASE/reference/html/_configuration_options.html
Destination
The target destination of a channel on the bound middleware (e.g., the RabbitMQ exchange or Kafka topic). If the channel is bound as a consumer, it could be bound to multiple destinations and the destination names can be specified as comma-separated String values. If not set, the channel name is used instead.
So my configuration
spring:
cloud:
stream:
default:
consumer:
concurrency: 2
partitioned: true
bindings:
# inputs
input:
group: application_name_group
destination: topic-1,topic-2
content-type: application/json;charset=UTF-8
Then I defined one consumer which handles messages from all these topics.
#Component
#EnableBinding(Sink.class)
public class CommonConsumer {
private final static Logger logger = LoggerFactory.getLogger(CommonConsumer.class);
#StreamListener(target = Sink.INPUT)
public void consumeMessage(final Message<Object> message) {
logger.info("Received a message: \nmessage:\n{}", message.getPayload());
// Here I define logic which handles messages depending on message headers and topic.
// In my case I have configuration which forwards these messages to webhooks, so I need to have mapping topic name -> webhook URI.
}
}
Note, in your case it may not be a solution. I needed to forward messages to webhooks, so I could have configuration mapping.
I also thought about other ideas.
1) You kafka client consumer without Spring Cloud.
2) Create a predefined number of inputs, for example 50.
input-1
intput-2
...
intput-50
And then have a configuration for some of these inputs.
Related discussions
Spring cloud stream to support routing messages dynamically
https://github.com/spring-cloud/spring-cloud-stream/issues/690
https://github.com/spring-cloud/spring-cloud-stream/issues/1089
We use Spring Cloud 2.1.1 RELEASE
MessageChannel messageChannel = createMessageChannel(channelName);
messageChannel.send(getMessageBuilder().apply(data));
public MessageChannel createMessageChannel(String channelName) {
return (MessageChannel) applicationContext.getBean(channelName);}
public Function<Object, Message<Object>> getMessageBuilder() {
return payload -> MessageBuilder
.withPayload(payload)
.setHeader(MessageHeaders.CONTENT_TYPE, MimeTypeUtils.APPLICATION_JSON)
.build();}
For the incoming messages, you can explicitly use BinderAwareChannelResolver to dynamically resolve the destination. You can check this example where router sink uses binder aware channel resolver.
maybe someone has an idea to my following problem:
I am currently on a project, where i want to use the AWS SQS with Spring Cloud integration. For the receiver part i want to provide a API, where a user can register a "message handler" on a queue, which is an interface and will contain the user's business logic, e.g.
MyAwsSqsReceiver receiver = new MyAwsSqsReceiver();
receiver.register("a-queue-name", new MessageHandler(){
#Override
public void handle(String message){
//... business logic for the received message
}
});
I found examples, e.g.
https://codemason.me/2016/03/12/amazon-aws-sqs-with-spring-cloud/
and read the docu
http://cloud.spring.io/spring-cloud-aws/spring-cloud-aws.html#_sqs_support
But the only thing i found there to "connect" a functionality for processing a incoming message is a annotation on a method, e.g. #SqsListener or #MessageMapping.
These annotations are fixed to a certain queue-name, though. So now i am at a loss, how to dynamically "connect" my provided "MessageHandler" (from my API) to the incoming message for the specified queuename.
In the Config the example there is a SimpleMessageListenerContainer, which gets a QueueMessageHandler set, but this QueueMessageHandler does not seem
to be the right place to set my handler or to override its methods and provide my own subclass of QueueMessageHandler.
I already did something like this with the Spring Amqp integration and RabbitMq and thought, that it would be also similar here with AWS SQS.
Does anyone have an idea, how to accomplish this?
thx + bye,
Ximon
EDIT:
I found, that Spring JMS could actually do that, e.g. www.javacodegeeks.com/2016/02/aws-sqs-spring-jms-integration.html. Does anybody know, what consequences using JMS protocol has here, good or bad?
I am facing the same issue.
I am trying to go in an unusual way where I set up an Aws client bean at build time and then instead of using sqslistener annotation to consume from the specific queue I use the scheduled annotation which I can programmatically pool (each 10 secs in my case) from which queue I want to consume.
I did the example that iterates over queues defined in properties and then consumes from each one.
Client Bean:
#Bean
#Primary
public AmazonSQSAsync awsSqsClient() {
return AmazonSQSAsyncClientBuilder
.standard()
.withRegion(Regions.EU_WEST_1.getName())
.build();
}
Consumer:
// injected in the constructor
private final AmazonSQSAsync awsSqsClient;
#Scheduled(fixedDelay = 10000)
public void pool() {
properties.getSqsQueues()
.forEach(queue -> {
val receiveMessageRequest = new ReceiveMessageRequest(queue)
.withWaitTimeSeconds(10)
.withMaxNumberOfMessages(10);
// reading the messages
val result = awsSqsClient.receiveMessage(receiveMessageRequest);
val sqsMessages = result.getMessages();
log.info("Received Message on queue {}: message = {}", queue, sqsMessages.toString());
// deleting the messages
sqsMessages.forEach(message -> {
val deleteMessageRequest = new DeleteMessageRequest(queue, message.getReceiptHandle());
awsSqsClient.deleteMessage(deleteMessageRequest);
});
});
}
Just to clarify, in my case, I need multiple queues, one for each tenant, with the queue URL for each one passed in a property file. Of course, in your case, you could get the queue names from another source, maybe a ThreadLocal which has the queues you have created in runtime.
If you wish, you can also try the JMS approach where you create message consumers and add a listener to each one you wish (See the doc Aws Jms documentation).
When we do Spring and SQS we use the spring-cloud-starter-aws-messaging.
Then just create a Listener class
#Component
public class MyListener {
#SQSListener(value="myqueue")
public void listen(MyMessageType message) {
//process the message
}
}