title: Confluent Schema Registry timed out error
body: <p>I'm using Avro schema to write data to Kafka topic. Initially, everything worked fine. After adding one more new field(scan_app_id) in avro file. I'm facing this error.</p>
  
  <blockquote>
    <p>Avro file:
    {</p>
    
    <p>"type": "record",   "name": "Initiate_Scan",   "namespace": "avro", 
    "doc": "Avro schema registry for Initiate_Scan",   "fields": [
        {
          "name": "app_id",
          "type": "string",
          "doc": "3 digit application id"
        },</p>
  
  <pre><code>{
    "name": "app_name",
    "type": "string",
    "doc": "application name"
  },
  {
    "name": "dev_stage",
    "type": "string",
    "doc": "development stage"
  },
  {
    "name": "scan_app_id",
    "type": "string",
    "doc": "unique scan id for an app in Veracode"
   },
  {
    "name": "scan_name",
    "type": "string",
    "doc": "scan details"
  },
  {
    "name": "seq_num",
    "type": "int",
    "doc": "unique number"
  },
  {
    "name": "result_flg",
    "type": "string",
    "doc": "Y indicates results of scan available",
    "default": "Y"
  },
   {
     "name": "request_id",
     "type": "int",
     "doc": "unique id"
   },
    {
      "name": "scan_number",
      "type": "int",
      "doc": "number of scans"
    }   ] }
  </code></pre>
    
    <p>Error:
     Caused by: org.apache.kafka.common.errors.SerializationException:
    Error registering Avro schema:
    {"type":"record","name":"Initiate_Scan","namespace":"avro","doc":"Avro
    schema registry for 
    Initiate_Scan","fields":[{"name":"app_id","type":{"type":"string","avro.java.string":"String"},"doc":"3
    digit application
    id"},{"name":"app_name","type":{"type":"string","avro.java.string":"String"},"doc":"application
    name"},{"name":"dev_stage","type":{"type":"string","avro.java.string":"String"},"doc":"development
    stage"},<strong>{"name":"scan_app_id","type":{"type":"string","avro.java.string":"String"},"doc":"unique
    scan id for an
    App"},</strong>{"name":"scan_name","type":{"type":"string","avro.java.string":"String"},"doc":"scan
    details"},{"name":"seq_num","type":"int","doc":"unique
    number"},{"name":"result_flg","type":{"type":"string","avro.java.string":"String"},"doc":"Y
    indicates results of scan
    available","default":"Y"},{"name":"request_id","type":"int","doc":"unique
    id"},{"name":"scan_number","type":"int","doc":"number of scans"}]}</p>
  </blockquote>
  
  <p>INFO Closing the Kafka producer with timeoutMillis = 9223372036854775807 ms. (org.apache.kafka.clients.producer.KafkaProducer:1017) 
  Caused by: io.confluent.kafka.schemaregistry.client.rest.exceptions.RestClientException: Register operation timed out; error code: 50002
      at io.confluent.kafka.schemaregistry.client.rest.RestService.sendHttpRequest(RestService.java:182)
      at io.confluent.kafka.schemaregistry.client.rest.RestService.httpRequest(RestService.java:203)
      at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:292)
      at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:284)
      at io.confluent.kafka.schemaregistry.client.rest.RestService.registerSchema(RestService.java:279)
      at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.registerAndGetId(CachedSchemaRegistryClient.java:61)
      at io.confluent.kafka.schemaregistry.client.CachedSchemaRegistryClient.register(CachedSchemaRegistryClient.java:93)
      at io.confluent.kafka.serializers.AbstractKafkaAvroSerializer.serializeImpl(AbstractKafkaAvroSerializer.java:72)
      at io.confluent.kafka.serializers.KafkaAvroSerializer.serialize(KafkaAvroSerializer.java:54)
      at org.apache.kafka.common.serialization.ExtendedSerializer$Wrapper.serialize(ExtendedSerializer.java:65)
      at org.apache.kafka.common.serialization.ExtendedSerializer$Wrapper.serialize(ExtendedSerializer.java:55)
      at org.apache.kafka.clients.producer.KafkaProducer.doSend(KafkaProducer.java:768)
      at org.apache.kafka.clients.producer.KafkaProducer.send(KafkaProducer.java:745)
      at com.ssc.svc.svds.initiate.InitiateProducer.initiateScanData(InitiateProducer.java:146)
      at com.ssc.svc.svds.initiate.InitiateProducer.topicsData(InitiateProducer.java:41)
      at com.ssc.svc.svds.initiate.InputData.main(InputData.java:31)</p>
  
  <p>I went through <a href="https://docs.confluent.io/current/schema-registry/develop/api.html" rel="nofollow noreferrer">Confluent documentation</a> about 50002 error, which says </p>
  
  <blockquote>
    <p>A schema should be compatible with the previously registered schema.</p>
  </blockquote>
  
  <p>Does this mean I cannot make changes/update existing schema ?</p>
  
  <p>How to fix this?</p>