3. Run the following command to install the C++ dependent library.
yum install librdkafka-devel
Step 2. Install the Node.js dependent library
1. Run the following command to specify the OpenSSL header file path for the preprocessor.
exportCPPFLAGS=-I/usr/local/opt/openssl/include
2. Run the following command to specify the OpenSSL library path for the connector.
exportLDFLAGS=-L/usr/local/opt/openssl/lib
3. Run the following command to install the Node.js dependent library.
npminstall i --unsafe-perm node-rdkafka
Step 3. Prepare configurations
Create the CKafka configuration file setting.js.
module.exports ={
'bootstrap_servers':["xxx.xx.xxx:xxxx"],
'topic_name':'xxx',
'group_id':'xxx'
}
Parameter
Description
bootstrap_servers
Accessed network, which can be copied from the Network column in the Access Mode section in Basic Info on the instance details page in the console.
topic_name
Topic name, which can be copied on the Topic Management page in the console.
group_id
You can customize it. After the demo runs successfully, you can see the consumer group on the Consumer Group page.
Step 4. Send messages
1. Write a message production program named producer.js.
const Kafka =require('node-rdkafka');
const config =require('./setting');
console.log("features:"+ Kafka.features);
console.log(Kafka.librdkafkaVersion);
var producer =newKafka.Producer({
'api.version.request':'true',
// To set the entry service, obtain the corresponding service address in the console.
'bootstrap.servers': config['bootstrap_servers'],
'dr_cb':true,
'dr_msg_cb':true,
// Number of retries upon request error. We recommend that you set the parameter to a value greater than 0 to enable retries and guarantee that messages are not lost to the greatest extent possible.
'retries':'0',
// Interval between a request failure and the next retry
"retry.backoff.ms":100,
// Network request timeout of the producer
'socket.timeout.ms':6000,
});
var connected =false
producer.setPollInterval(100);
producer.connect();
producer.on('ready',function(){
connected =true
console.log("connect ok")
});
producer.on("disconnected",function(){
connected =false;
producer.connect();
})
producer.on('event.log',function(event){
console.log("event.log", event);
});
producer.on("error",function(error){
console.log("error:"+ error);
});
functionproduce(){
try{
producer.produce(
config['topic_name'],
null,
newBuffer('Hello CKafka Default'),
null,
Date.now()
);
}catch(err){
console.error('Error occurred when sending message(s)');
4. On the Topic Management tab on the instance details page in the CKafka console, select the target topic and click More > Message Query to view the message just sent.
Step 5. Subscribe to messages
1. Create the message consumption program consumer.js.
const Kafka =require('node-rdkafka');
const config =require('./setting');
console.log(Kafka.features);
console.log(Kafka.librdkafkaVersion);
console.log(config)
var consumer =newKafka.KafkaConsumer({
'api.version.request':'true',
// To set the entry service, obtain the corresponding service address in the console.
'bootstrap.servers': config['bootstrap_servers'],
'group.id': config['group_id'],
// Consumer timeout period when the Kafka consumer grouping mechanism is used. If the broker does not receive the heartbeat of the consumer within this period,
// the consumer will be considered to have failed and the broker will initiate rebalancing again.
'session.timeout.ms':10000,
// Client request timeout period. If no response is received after this time elapses, the request will time out and fail.
'metadata.request.timeout.ms':305000,
// Set the internal retry interval of the client
'reconnect.backoff.max.ms':3000
});
consumer.connect();
consumer.on('ready',function(){
console.log("connect ok");
consumer.subscribe([config['topic_name']]);
consumer.consume();
})
consumer.on('data',function(data){
console.log(data);
});
consumer.on('event.log',function(event){
console.log("event.log", event);
});
consumer.on('error',function(error){
console.log("error:"+ error);
});
consumer.on('event',function(event){
console.log("event:"+ event);
});
2. Execute the following command to send messages.
node consumer.js
3. View the execution result.
4. On the Consumer Group page in the Ckafka console, click the triangle icon on the left of the target consumer group name, enter the topic name in the search box, and click View Details to view the consumption details.
Yes
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