Add require_ack_response option

lib/fluent/logger/fluent_logger.rb

@@ -90,6 +90,9 @@ def initialize(tag_prefix = nil, *args)
         end
         @packer = @factory.packer
 
+        @require_ack_response = options[:require_ack_response]
+        @ack_response_timeout = options[:ack_response_timeout] || 190
+
         @mon = Monitor.new
         @pending = nil
         @connect_error_history = []
@@ -144,7 +147,7 @@ def close
           if @pending
             begin
               @pending.each do |tag, record|
-                send_data([tag, record].to_msgpack)
+                send_data(tag, record)
               end
             rescue => e
               set_last_error(e)
@@ -232,7 +235,7 @@ def write(tag, time, map)
 
           begin
             @pending.each do |tag, record|
-              send_data([tag, record].to_msgpack)
+              send_data(tag, record)
             end
             @pending = nil
             true
@@ -250,11 +253,17 @@ def write(tag, time, map)
         }
       end
 
-      def send_data(data)
+      def send_data(tag, record)
         unless connect?
           connect!
         end
-        @con.write data
+        if @require_ack_response
+          option = {}
+          option['chunk'] = generate_chunk
+          @con.write [tag, record, option].to_msgpack
+        else
+          @con.write [tag, record].to_msgpack
+        end
         #while true
         #  puts "sending #{data.length} bytes"
         #  if data.length > 32*1024
@@ -269,6 +278,21 @@ def send_data(data)
         #  data = data[n..-1]
         #end
 
+        if @require_ack_response && @ack_response_timeout > 0
+          if IO.select([@con], nil, nil, @ack_response_timeout)
+            raw_data = @con.recv(1024)
+
+            if raw_data.empty?
+              raise "Closed connection"
+            else
+              response = MessagePack.unpack(raw_data)
+              if response['ack'] != option['chunk']
+                raise "ack in response and chunk id in sent data are different"
+              end
+            end
+          end
+        end
+
         true
       end
 
@@ -307,6 +331,10 @@ def set_last_error(e)
         # TODO: Check non GVL env
         @last_error[Thread.current.object_id] = e
       end
+
+      def generate_chunk
+        Base64.encode64(([SecureRandom.random_number(1 << 32)] * 4).pack('NNNN')).chomp
+      end
     end
   end
 end