Connection refused error while producing record into MSK topic using schema registry

Question

So i have been able to register schema and produce and consume from command line . This is how i have done .

bin/kafka-avro-console-producer --broker-list b-****.xt08nj.c5.kafka.us-east-1.amazonaws.com:9092,b-6.****.xt08nj.c5.kafka.us-east-1.amazonaws.com:9092,b-***.xt08nj.c5.kafka.us-east-1.amazonaws.com:9092 --topic AVRO-AUDIT_EVENT --property schema.registry.url=http://localhost:8081 --property value.schema='{ "type":"record", "namespace":"com.example", "name":"AuditEvents", "doc":"Avro schema for our Audit Event table", "fields":[ {"name":"ID","type":"string","doc":"id for the event"}, {"name":"VERSION","type":"string","doc":"Version of audit event "}, {"name":"ACTION_TYPE","type":"string","doc":"what action has perfomed "}, {"name":"EVENT_TYPE","type":"string","doc":"what was the event "}, {"name":"CLIENT_ID","type":"string","doc":"id of the client "}, {"name":"DETAILS","type":"string","doc":"details about the event"}, {"name":"OBJECT_TYPE","type":"string","doc":"the type of audit event object"}, {"name":"UTC_DATE_TIME","type":"string","doc":"audit event date time "}, {"name":"POINT_IN_TIME_PRECISION","type":"string","doc":"POINT_IN_TIME_PRECISION"}, {"name":"TIME_ZONE","type":"string","doc":"TIME_ZONE"}, {"name":"TIMELINE_PRECISION","type":"string","doc":"TIMELINE_PRECISION"}, {"name":"GROUP_ID","type":"string","doc":"GROUP_ID"}, {"name":"OBJECT_DISPLAY_NAME","type":"string","doc":"OBJECT_DISPLAY_NAME"}, {"name":"OBJECT_ID","type":"string","doc":"OBJECT_ID"}, {"name":"USER_DISPLAY_NAME","type":"string","doc":"USER_DISPLAY_NAME"}, {"name":"USER_ID","type":"string","doc":"USER_ID"}, {"name":"PARENT_EVENT_ID","type":"string","doc":"PARENT_EVENT_ID"}, {"name":"NOTES","type":"string","doc":"NOTES"}, {"name":"SUMMARY","type":"string","doc":"SUMMARY"}, {"name":"AUDIT_EVENT_TO_UTC_DT","type":"string","doc":"AUDIT_EVENT_TO_UTC_DT"}, {"name":"AUDIT_EVENT_TO_DATE_PITP","type":"string","doc":"AUDIT_EVENT_TO_DATE_PITP"}, {"name":"AUDIT_EVENT_TO_DATE_TZ","type":"string","doc":"AUDIT_EVENT_TO_DATE_TZ"}, {"name":"AUDIT_EVENT_TO_DATE_TP","type":"string","doc":"AUDIT_EVENT_TO_DATE_TP"} ] }'

I was able to consume from avro console as well .

Now i want to put this from java producer with some hardcoded value . When i do that i get connection refused error .

Here is my java code .

props.setProperty("acks", "all");
        props.setProperty("retries", "10");
        // avro part
        props.setProperty("key.serializer", StringSerializer.class.getName());
        props.setProperty("value.serializer", KafkaAvroSerializer.class.getName());

        props.put("schema.registry.url", "http://localhost:8081/");

        Producer<String, AuditEvents> producer = new KafkaProducer<String, AuditEvents>(props);

        // copied from avro examples
        AuditEvents auditEvent = AuditEvents.newBuilder().setID("avro-lambda-1-5d17-136a-9749-0e710000fd04")
                .setVERSION("1").setACTIONTYPE("NEW_CASE").setEVENTTYPE("WORLDCHECK")
                .setCLIENTID("fgh-5d1e-17a2-9749-0e4d0000146d")
                .setDETAILS(
                        "<?xml version=\"1.0\" encoding=\"UTF-8\" standalone=\"yes\"?><caseCreatedPayload><batchDetails/><caseId>0a348753-5d1e-17af-9749-0e7100006ccf</caseId><clientCaseId>case159</clientCaseId><caseName>William Mendoza</caseName><entityType>INDIVIDUAL</entityType><updateDate><dateTime>2017-07-08T22:02:32.211Z</dateTime><timeZone>UTC</timeZone><timelinePrecision>ON</timelinePrecision><pointInTimePrecision>TIME</pointInTimePrecision></updateDate><createDate><dateTime>2017-07-08T22:02:32.211Z</dateTime><timeZone>UTC</timeZone><timelinePrecision>ON</timelinePrecision><pointInTimePrecision>TIME</pointInTimePrecision></createDate><groupName>TEST_PERFORMANCE_CLIENT_2da27301-d44f-475f-92a2-1838b640d88b</groupName><nameTransposition><selected>false</selected><type>NAME_TRANSPOSITION</type><available>false</available></nameTransposition><gender>MALE</gender></caseCreatedPayload>")
                .setOBJECTTYPE("CASE").setUTCDATETIME("1578469623000").setPOINTINTIMEPRECISION("TIME")
                .setTIMEZONE("UTC").setTIMELINEPRECISION("ON").setGROUPID("0a348753-5d1e-17a2-9749-0e4d0000146d")
                .setOBJECTDISPLAYNAME("NULL").setOBJECTID("0a348753-5d1e-17af-9749-0e7100006ccf")
                .setUSERDISPLAYNAME("USER_FIRST_6cb4c322-cd3d-4809-97d3-07d2d96f10ed")
                .setUSERID("USER_LAST_7e99cad9-dc1c-4770-ac4f-33c4897ce404")
                .setPARENTEVENTID("parenteventid")
                .setEVENTTYPE("0a348752-5d17-138e-9749-0e6a00000c7f").setNOTES("NOTES").setSUMMARY("SUMMARY IN XML")
                .setAUDITEVENTTOUTCDT("1578469623000").setAUDITEVENTTODATEPITP("NULL").setAUDITEVENTTODATETZ("null")
                .setAUDITEVENTTODATETP("null").build();

        ProducerRecord<String, AuditEvents> producerRecord = new ProducerRecord<String, AuditEvents>(topic, auditEvent);

        System.out.println("*******auditEvent****"+auditEvent);
        producer.send(producerRecord, new Callback() {
            @Override
            public void onCompletion(RecordMetadata metadata, Exception exception) {
                if (exception == null) {
                    System.out.println(metadata);
                } else {
                    exception.printStackTrace();
                }
            }
        });

        producer.flush();
        producer.close();

This is the error stack trace

Error serializing Avro message: org.apache.kafka.common.errors.SerializationException
org.apache.kafka.common.errors.SerializationException: Error serializing Avro message
Caused by: java.net.ConnectException: Connection refused (Connection refused)
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
    at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
    at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    at java.net.Socket.connect(Socket.java:589)
    at sun.net.NetworkClient.doConnect(NetworkClient.java:175)
    at sun.net.www.http.HttpClient.openServer(HttpClient.java:463)
    at sun.net.www.http.HttpClient.openServer(HttpClient.java:558)
    at sun.net.www.http.HttpClient.<init>(HttpClient.java:242)
    at sun.net.www.http.HttpClient.New(HttpClient.java:339)
    at sun.net.www.http.HttpClient.New(HttpClient.java:357)
    at sun.net.www.protocol.http.HttpURLConnection.getNewHttpClient(HttpURLConnection.java:1220)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect0(HttpURLConnection.java:1156)
    at sun.net.www.protocol.http.HttpURLConnection.plainConnect(HttpURLConnection.java:1050)
    at sun.net.www.protocol.http.HttpURLConnection.connect(HttpURLConnection.java:984)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream0(HttpURLConnection.java:1334)
    at sun.net.www.protocol.http.HttpURLConnection.getOutputStream(HttpURLConnection.java:1309)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.sendHttpRequest(RestService.java:199)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.httpRequest(RestService.java:256)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:356)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:348)
    at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:334)
    at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.registerAndGetId(CachedSchemaRegistryClient.java:168)
    at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.register(CachedSchemaRegistryClient.java:222)
    at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.register(CachedSchemaRegistryClient.java:198)
    at io.confluent.kafka.serializers.AbstractKafkaAvroSerializer.serializeImpl(AbstractKafkaAvroSerializer.java:70)
    at io.confluent.kafka.serializers.KafkaAvroSerializer.serialize(KafkaAvroSerializer.java:53)
    at org.apache.kafka.common.serialization.Serializer.serialize(Serializer.java:62)
    at org.apache.kafka.clients.producer.KafkaProducer.doSend(KafkaProducer.java:894)
    at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:856)
    at com.amazonaws.lambda.demo.Producer_apilambdamskavro.handleRequest(Producer_apilambdamskavro.java:68)
    at com.amazonaws.lambda.demo.Producer_apilambdamskavro.handleRequest(Producer_apilambdamskavro.java:20)

Please suggest what i am missing . The way i created schema was wrong ?

Why do you think the Schema is wrong? Please show the full error.... For example, you never set `bootstrap.servers`. Note: It is recommended to use `ProducerConfig.{PROP}_CONFIG` constants rather than strings — OneCricketeer, Jan 15 '20 at 02:04
Schema is correct .i have not shown bootstrap server here .But i am setting .ProducerConfig is stander ,but will it fail because of that ? — Atharv Thakur, Jan 15 '20 at 06:15
No, using a constant is just preferred. The console producer is just a Java class internally, so it should report same errors — OneCricketeer, Jan 15 '20 at 06:25
so this is the correct way `props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "io.confluent.kafka.serializers.KafkaAvroSerializer")` ? — Atharv Thakur, Jan 15 '20 at 06:26
@cricket_007 did change as suggested but still getting same error ...Connection refused — Atharv Thakur, Jan 15 '20 at 06:31
It's not a fix. It's just a recommendation. I feel like there is more stacktrace that you've cut off — OneCricketeer, Jan 15 '20 at 06:33
@cricket_007 Thats all i get ..Do i have change key also as KafkaAvroSerializer? i am sending only key as avro — Atharv Thakur, Jan 15 '20 at 06:34
No. Your schema registry isn't running or your brokers are wrong. Has nothing to do with Avro schemas or serializers — OneCricketeer, Jan 15 '20 at 06:35
@cricket_007 i can see that schema is running `INFO Server started, listening for requests... (io.confluent.kafka.schemaregistry.rest.SchemaRegistryMain:44)` i am running producer from lambda function and my schema is on EC2 ..and i jave connectivity as well — Atharv Thakur, Jan 15 '20 at 06:40
Uh. Your lambda isn't running a Schema Registry, and cannot reach localhost "your machine" from AWS. You need to deploy the Registry is EC2 or ECS/EKS — OneCricketeer, Jan 15 '20 at 06:48
@cricket_007 my registry in in EC2 ..and my lambda fnction is also in aws ..I am not running it on my local laptop ...All deployed in AWS — Atharv Thakur, Jan 15 '20 at 06:53
Okay, still, you cannot use localhost for anything. You need to use the proper DNS entry or IP — OneCricketeer, Jan 15 '20 at 06:54
@cricket_007 yes it worked ...Fantastic ...Finally after 3 days i am able understand schema registry and java and all ...Thanks for you guidance and patience .Please put your answer so that i can mark this as accepted ..Thanks a looot... — Atharv Thakur, Jan 15 '20 at 07:02

score 0 · Accepted Answer · answered Jan 15 '20 at 07:18

You didn't specify where your code is running, but the stacktrace suggests your registry address is incorrect or the registry is not running on the address you pointed at

props.put("schema.registry.url", "http://localhost:8081/");

If it's not running on the same physical machine as the producer, you need to change the address to point at the correct location

Connection refused error while producing record into MSK topic using schema registry

1 Answers1