Add reduce_max_size_error_message configuration

README.md

@@ -178,6 +178,9 @@ If your record contains a field whose string should be sent to Amazon Kinesis di
 ### log_truncate_max_size
 Integer, default 0. When emitting the log entry, the message will be truncated by this size to avoid infinite loop when the log is also sent to Kinesis. The value 0 (default) means no truncation.
 
+### reduce_max_size_error_message
+Boolean, default false. When each record exceeds the maximum size, the original record is put on its error message. If this parameter is turned on, the error message will contain only summarized data to prevent large traffic generated by the error message.
+
 ## Configuration: kinesis_streams
 Here are `kinesis_streams` specific configurations.
 

lib/fluent/plugin/kinesis_helper/class_methods.rb

@@ -92,6 +92,7 @@ def config_param_for_format
         config_param :formatter,             :string,  default: 'json'
         config_param :data_key,              :string,  default: nil
         config_param :log_truncate_max_size, :integer, default: 0
+        config_param :reduce_max_size_error_message, :bool, default: false
       end
 
       def config_param_for_batch_request

lib/fluent/plugin/kinesis_helper/error.rb

@@ -24,8 +24,13 @@ def initialize(key, record)
     end
 
     class ExceedMaxRecordSizeError < SkipRecordError
-      def initialize(record)
-        super "Record size limit exceeded for #{record}"
+      def initialize(record, reduce_message)
+        if reduce_message == true
+          sampled_record = "#{record.slice(0,1024)}...#{record.slice(-1024,1024)}"
+          super "Record size limit exceeded for #{record.length}-bytes record: #{sampled_record}"
+        else
+          super "Record size limit exceeded for #{record}"
+        end
       end
     end
 

lib/fluent/plugin/kinesis_helper/format.rb

@@ -64,7 +64,7 @@ def convert_record(tag, time, record)
         converted = convert_format(tag, time, record)
         converted[:data] += "\n" if @append_new_line
         if converted[:data].size > MaxRecordSize
-          raise ExceedMaxRecordSizeError, converted[:data]
+          raise ExceedMaxRecordSizeError.new(converted[:data], @reduce_max_size_error_message)
         else
           converted
         end

test/kinesis_helper/test_format.rb

@@ -19,10 +19,11 @@ class KinesisHelperFormatTest < Test::Unit::TestCase
   class Mock
     include Fluent::KinesisHelper::Format
 
-    attr_accessor :log_truncate_max_size
+    attr_accessor :log_truncate_max_size, :reduce_max_size_error_message
 
     def initialize
       @log_truncate_max_size = 0
+      @reduce_max_size_error_message = false
     end
 
     def log
@@ -60,6 +61,19 @@ def test_convert_record_max_record_size(data)
     assert_equal result.nil? ? 1 : 0, @object.log.logs.size
   end
 
+  data(
+    'default' => [false, :>],
+    'reduce'  => [true,  :<],
+  )
+  def test_reduce_max_size_error_message(data)
+    @object.reduce_max_size_error_message, expected = data
+    record = {"a"=>"a"*(1024*1024-'{"a":""}'.size+1)}
+    result = @object.send(:convert_record, '', '', record)
+    assert_equal nil, result
+    assert_equal 1, @object.log.logs.size
+    assert_operator @object.log.logs.first.size, expected, record.to_s.size
+  end
+
   data(
     '1'     => [1,   "1"],
     '5'     => [5,   "12345"],