diff --git a/lib/fluent/event.rb b/lib/fluent/event.rb
index 2fe2a2525d..f25d8a21fc 100644
--- a/lib/fluent/event.rb
+++ b/lib/fluent/event.rb
@@ -50,30 +50,30 @@ def slice(index, num)
       raise NotImplementedError, "DO NOT USE THIS CLASS directly."
     end
 
-    def each(&block)
+    def each(unapcker: nil, &block)
       raise NotImplementedError, "DO NOT USE THIS CLASS directly."
     end
 
-    def to_msgpack_stream(time_int: false)
-      return to_msgpack_stream_forced_integer if time_int
-      out = msgpack_packer
+    def to_msgpack_stream(time_int: false, packer: nil)
+      return to_msgpack_stream_forced_integer(packer: packer) if time_int
+      out = packer || msgpack_packer
       each {|time,record|
         out.write([time,record])
       }
-      out.to_s
+      out.full_pack
     end
 
-    def to_compressed_msgpack_stream(time_int: false)
-      packed = to_msgpack_stream(time_int: time_int)
+    def to_compressed_msgpack_stream(time_int: false, packer: nil)
+      packed = to_msgpack_stream(time_int: time_int, packer: packer)
       compress(packed)
     end
 
-    def to_msgpack_stream_forced_integer
-      out = msgpack_packer
+    def to_msgpack_stream_forced_integer(packer: nil)
+      out = packer || msgpack_packer
       each {|time,record|
         out.write([time.to_i,record])
       }
-      out.to_s
+      out.full_pack
     end
   end
 
@@ -107,7 +107,7 @@ def slice(index, num)
       end
     end
 
-    def each(&block)
+    def each(unpacker: nil, &block)
       block.call(@time, @record)
       nil
     end
@@ -143,7 +143,7 @@ def slice(index, num)
       ArrayEventStream.new(@entries.slice(index, num))
     end
 
-    def each(&block)
+    def each(unpacker: nil, &block)
       @entries.each(&block)
       nil
     end
@@ -190,7 +190,7 @@ def slice(index, num)
       MultiEventStream.new(@time_array.slice(index, num), @record_array.slice(index, num))
     end
 
-    def each(&block)
+    def each(unpacker: nil, &block)
       time_array = @time_array
       record_array = @record_array
       for i in 0..time_array.length-1
@@ -234,11 +234,11 @@ def repeatable?
       true
     end
 
-    def ensure_unpacked!
+    def ensure_unpacked!(unpacker: nil)
       return if @unpacked_times && @unpacked_records
       @unpacked_times = []
       @unpacked_records = []
-      msgpack_unpacker.feed_each(@data) do |time, record|
+      (unpacker || msgpack_unpacker).feed_each(@data) do |time, record|
         @unpacked_times << time
         @unpacked_records << record
       end
@@ -254,7 +254,7 @@ def slice(index, num)
       MultiEventStream.new(@unpacked_times.slice(index, num), @unpacked_records.slice(index, num))
     end
 
-    def each(&block)
+    def each(unpacker: nil, &block)
       if @unpacked_times
         @unpacked_times.each_with_index do |time, i|
           block.call(time, @unpacked_records[i])
@@ -262,7 +262,7 @@ def each(&block)
       else
         @unpacked_times = []
         @unpacked_records = []
-        msgpack_unpacker.feed_each(@data) do |time, record|
+        (unpacker || msgpack_unpacker).feed_each(@data) do |time, record|
           @unpacked_times << time
           @unpacked_records << record
           block.call(time, record)
@@ -272,7 +272,7 @@ def each(&block)
       nil
     end
 
-    def to_msgpack_stream(time_int: false)
+    def to_msgpack_stream(time_int: false, packer: nil)
       # time_int is always ignored because @data is always packed binary in this class
       @data
     end
@@ -290,17 +290,17 @@ def empty?
       super
     end
 
-    def ensure_unpacked!
+    def ensure_unpacked!(unpacker: nil)
       ensure_decompressed!
       super
     end
 
-    def each(&block)
+    def each(unpacker: nil, &block)
       ensure_decompressed!
       super
     end
 
-    def to_msgpack_stream(time_int: false)
+    def to_msgpack_stream(time_int: false, packer: nil)
       ensure_decompressed!
       super
     end
@@ -322,15 +322,15 @@ module ChunkMessagePackEventStreamer
     include MessagePackFactory::Mixin
     # chunk.extend(ChunkEventStreamer)
     #  => chunk.each{|time, record| ... }
-    def each(&block)
+    def each(unpacker: nil, &block)
       open do |io|
-        msgpack_unpacker(io).each(&block)
+        (unpacker || msgpack_unpacker(io)).each(&block)
       end
       nil
     end
     alias :msgpack_each :each
 
-    def to_msgpack_stream(time_int: false)
+    def to_msgpack_stream(time_int: false, packer: nil)
       # time_int is always ignored because data is already packed and written in chunk
       read
     end
diff --git a/lib/fluent/event_router.rb b/lib/fluent/event_router.rb
index 23db13a66c..365fba4b94 100644
--- a/lib/fluent/event_router.rb
+++ b/lib/fluent/event_router.rb
@@ -17,6 +17,7 @@
 require 'fluent/match'
 require 'fluent/event'
 require 'fluent/filter'
+require 'fluent/msgpack_factory'
 
 module Fluent
   #
@@ -182,7 +183,7 @@ def filter_stream(tag, es)
 
         def optimized_filter_stream(tag, es)
           new_es = MultiEventStream.new
-          es.each do |time, record|
+          es.each(unpacker: Fluent::MessagePackFactory.thread_local_msgpack_unpacker) do |time, record|
             filtered_record = record
             filtered_time = time
 
diff --git a/lib/fluent/msgpack_factory.rb b/lib/fluent/msgpack_factory.rb
index 54d0b9033e..0b34a59c04 100644
--- a/lib/fluent/msgpack_factory.rb
+++ b/lib/fluent/msgpack_factory.rb
@@ -58,5 +58,13 @@ def self.init
       factory.register_type(Fluent::EventTime::TYPE, Fluent::EventTime)
       @@engine_factory = factory
     end
+
+    def self.thread_local_msgpack_packer
+      Thread.current[:local_msgpack_packer] ||= MessagePackFactory.engine_factory.packer
+    end
+
+    def self.thread_local_msgpack_unpacker
+      Thread.current[:local_msgpack_unpacker] ||= MessagePackFactory.engine_factory.unpacker
+    end
   end
 end
diff --git a/lib/fluent/plugin/buffer/file_chunk.rb b/lib/fluent/plugin/buffer/file_chunk.rb
index 81245ad8d5..934ffd3c3f 100644
--- a/lib/fluent/plugin/buffer/file_chunk.rb
+++ b/lib/fluent/plugin/buffer/file_chunk.rb
@@ -254,7 +254,7 @@ def write_metadata(update: true)
               c: @created_at,
               m: (update ? Fluent::Clock.real_now : @modified_at),
           })
-          bin = msgpack_packer.pack(data).to_s
+          bin = Fluent::MessagePackFactory.thread_local_msgpack_packer.pack(data).full_pack
           size = [bin.bytesize].pack('N')
           @meta.seek(0, IO::SEEK_SET)
           @meta.write(BUFFER_HEADER + size + bin)
diff --git a/lib/fluent/plugin/output.rb b/lib/fluent/plugin/output.rb
index 16f07ac8bb..5208f445aa 100644
--- a/lib/fluent/plugin/output.rb
+++ b/lib/fluent/plugin/output.rb
@@ -18,6 +18,7 @@
 require 'fluent/plugin/base'
 require 'fluent/plugin/buffer'
 require 'fluent/plugin_helper/record_accessor'
+require 'fluent/msgpack_factory'
 require 'fluent/log'
 require 'fluent/plugin_id'
 require 'fluent/plugin_helper'
@@ -912,10 +913,10 @@ def write_guard(&block)
         end
       end
 
-      FORMAT_MSGPACK_STREAM = ->(e){ e.to_msgpack_stream }
-      FORMAT_COMPRESSED_MSGPACK_STREAM = ->(e){ e.to_compressed_msgpack_stream }
-      FORMAT_MSGPACK_STREAM_TIME_INT = ->(e){ e.to_msgpack_stream(time_int: true) }
-      FORMAT_COMPRESSED_MSGPACK_STREAM_TIME_INT = ->(e){ e.to_compressed_msgpack_stream(time_int: true) }
+      FORMAT_MSGPACK_STREAM = ->(e){ e.to_msgpack_stream(packer: Fluent::MessagePackFactory.thread_local_msgpack_packer) }
+      FORMAT_COMPRESSED_MSGPACK_STREAM = ->(e){ e.to_compressed_msgpack_stream(packer: Fluent::MessagePackFactory.thread_local_msgpack_packer) }
+      FORMAT_MSGPACK_STREAM_TIME_INT = ->(e){ e.to_msgpack_stream(time_int: true, packer: Fluent::MessagePackFactory.thread_local_msgpack_packer) }
+      FORMAT_COMPRESSED_MSGPACK_STREAM_TIME_INT = ->(e){ e.to_compressed_msgpack_stream(time_int: true, packer: Fluent::MessagePackFactory.thread_local_msgpack_packer) }
 
       def generate_format_proc
         if @buffer && @buffer.compress == :gzip
@@ -937,7 +938,7 @@ def generate_format_proc
       def handle_stream_with_custom_format(tag, es, enqueue: false)
         meta_and_data = {}
         records = 0
-        es.each do |time, record|
+        es.each(unpacker: Fluent::MessagePackFactory.thread_local_msgpack_unpacker) do |time, record|
           meta = metadata(tag, time, record)
           meta_and_data[meta] ||= []
           res = format(tag, time, record)
@@ -957,7 +958,7 @@ def handle_stream_with_standard_format(tag, es, enqueue: false)
         format_proc = generate_format_proc
         meta_and_data = {}
         records = 0
-        es.each do |time, record|
+        es.each(unpacker: Fluent::MessagePackFactory.thread_local_msgpack_unpacker) do |time, record|
           meta = metadata(tag, time, record)
           meta_and_data[meta] ||= MultiEventStream.new
           meta_and_data[meta].add(time, record)
@@ -977,7 +978,7 @@ def handle_stream_simple(tag, es, enqueue: false)
         if @custom_format
           records = 0
           data = []
-          es.each do |time, record|
+          es.each(unpacker: Fluent::MessagePackFactory.thread_local_msgpack_unpacker) do |time, record|
             res = format(tag, time, record)
             if res
               data << res