protobuf decode error

[ghostPM]

When i'm using logstash-codec-protobuf with plugin version 1.0.3 to decode my msg receive from kafka, I got the error in the following:

[2017-12-28T18:27:48,741][WARN ][logstash.codecs.protobuf ] Couldn't decode protobuf: #<ProtocolBuffers::DecodeError: invalid message>.

I'm not sure if the plugin support protobuf version 2.x? Since I use protoc with version 2.6.1.

I use the ruby-protocol-buffers which is recommended by logstash-codec-protobuf. The following shows my idl and rb files:

idl:

option java_package = "com.hiido.mobileyy.type.count.proto";

message MessageList{

    required int32 message_num = 1;
    repeated bytes messages = 2;
    required int32 parse_type = 3;

}

generated rb file:

#!/usr/bin/env ruby
# Generated by the protocol buffer compiler. DO NOT EDIT!

require 'protocol_buffers'

# forward declarations
class MessageList < ::ProtocolBuffers::Message; end

class MessageList < ::ProtocolBuffers::Message
  set_fully_qualified_name "MessageList"

  required :int32, :message_num, 1
  repeated :bytes, :messages, 2
  required :int32, :parse_type, 3
end

and my logstash config file is like:

input {
  kafka {
    topics => ["mytopic"]
    bootstrap_servers => "127.0.0.1:9092"
    codec => protobuf {
      class_name => "MessageList"
      include_path => ['D:/temp/logstash/stream_message_list.pb.rb']
    }
  }
}
output {
  stdout {}
}

[ghostPM]

I have resolved it, since I forgot to set the value_deserializer_class property of kafka to org.apache.kafka.common.serialization.ByteArrayDeserializer which refers protobuf's data.

Thank you