How to add optional new record fields and/or new methods in avro-ipc?

[常冰琳]

Hi,
I try to use avro-ipc in my project and got a problem, if the server side
needs to upgrade,
add a few optional field to Request/Response object, or add a new method,
thus change the
schema.
I use reflect, add a new String field in Request class with @Nullable in
server side, keep client
side unchanged, but it won't to work.
I think protobuf supports this, just by adding new optional fields.
So does it possible or how to support backward compatibility in other way?

Here is the protocol class


old:



public interface SampleService {
  public static class Request {
    int id;
    String name;
    @Nullable
    String address;

    public Request() {
      this(0, "null", null);
    }

    public Request(int id, String name, String address) {
      this.id = id;
      this.name = name;
      this.address = address;
    }

    public int getId() {
      return id;
    }

    public String getName() {
      return name;
    }

    public String getAddress() {
      return address;
    }

  }

  public static class Response {
    @Nullable
    String value;

    public Response() {
      this("null");
    }
    public Response(String value) {
      this.value = value;
    }

    public String getValue() {
      return value;
    }
  }

  int fibonacci(int n);
  int sum(int [] nums, int base);
  Response complexCall(Request req);
}




new:


public interface SampleService {
  public static class Request {
    int id;
    String name;
    @Nullable
    String address;
    @Nullable
    String address2;

    public Request() {
      this(0, "null", null, null);
    }

    public Request(int id, String name, String address, String address2) {
      this.id = id;
      this.name = name;
      this.address = address;
      this.address2 = address2;
    }

    public int getId() {
      return id;
    }

    public String getName() {
      return name;
    }

    public String getAddress() {
      return address;
    }

    public String getAddress2() {
      return address2;
    }

  }

  public static class Response {
    @Nullable
    String value;

    public Response() {
      this("null");
    }
    public Response(String value) {
      this.value = value;
    }

    public String getValue() {
      return value;
    }
  }

  int fibonacci(int n);
  int sum(int [] nums, int base);
  Response complexCall(Request req);
}


Here is the error message:

Exception in thread "main" org.apache.avro.AvroRuntimeException:
org.apache.avro.AvroTypeException: Found {
  "type" : "record",
  "name" : "Request",
  "namespace" : "com.mycompany.app.SampleService$",
  "fields" : [ {
    "name" : "id",
    "type" : "int"
  }, {
    "name" : "name",
    "type" : "string"
  }, {
    "name" : "address",
    "type" : [ "null", "string" ]
  } ]
}, expecting {
  "type" : "record",
  "name" : "Request",
  "namespace" : "com.mycompany.app.SampleService$",
  "fields" : [ {
    "name" : "id",
    "type" : "int"
  }, {
    "name" : "name",
    "type" : "string"
  }, {
    "name" : "address",
    "type" : [ "null", "string" ]
  }, {
    "name" : "address2",
    "type" : [ "null", "string" ]
  } ]
}
at
org.apache.avro.ipc.specific.SpecificRequestor.readError(SpecificRequestor.java:126)
at org.apache.avro.ipc.Requestor$Response.getResponse(Requestor.java:555)
at
org.apache.avro.ipc.Requestor$TransceiverCallback.handleResult(Requestor.java:360)
at
org.apache.avro.ipc.Requestor$TransceiverCallback.handleResult(Requestor.java:323)
at
org.apache.avro.ipc.NettyTransceiver$NettyClientAvroHandler.messageReceived(NettyTransceiver.java:382)
at
org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:80)
at
org.apache.avro.ipc.NettyTransceiver$NettyClientAvroHandler.handleUpstream(NettyTransceiver.java:364)
at
org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:545)
at
org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(DefaultChannelPipeline.java:754)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:302)
at
org.jboss.netty.handler.codec.frame.FrameDecoder.unfoldAndFireMessageReceived(FrameDecoder.java:317)
at
org.jboss.netty.handler.codec.frame.FrameDecoder.callDecode(FrameDecoder.java:299)
at
org.jboss.netty.handler.codec.frame.FrameDecoder.messageReceived(FrameDecoder.java:216)
at
org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(SimpleChannelUpstreamHandler.java:80)
at
org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:545)
at
org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline.java:540)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:274)
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:261)
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:349)
at
org.jboss.netty.channel.socket.nio.NioWorker.processSelectedKeys(NioWorker.java:280)
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:200)
at
org.jboss.netty.util.ThreadRenamingRunnable.run(ThreadRenamingRunnable.java:108)
at
org.jboss.netty.util.internal.DeadLockProofWorker$1.run(DeadLockProofWorker.java:44)
at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:680)