Logstash crashed with IdentityMapUpperLimitException

Logstash crashed with the following error.

LogStash::Codecs::IdentityMapCodec::IdentityMapUpperLimitException: LogStash::Codecs::IdentityMapCodec::IdentityMapUpperLimitException
visit at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:37
check_map_limits at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:327
record_codec_usage at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:306
stream_codec at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:297
accept at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:179
accept at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-input-file-2.2.5/lib/logstash/inputs/file.rb:250
observe_read_file at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:79
each at org/jruby/RubyArray.java:1613
observe_read_file at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:78
loop at org/jruby/RubyKernel.java:1479
observe_read_file at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:74
subscribe at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:39
each at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:187
each at org/jruby/RubyArray.java:1613
each at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:176
each at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:120
call at org/jruby/RubyProc.java:281
synchronized at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:357
synchronize at org/jruby/ext/thread/Mutex.java:149
synchronized at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:357
each at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:118
subscribe at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:280
subscribe at /opt/logstash/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:23
subscribe at /opt/logstash/vendor/jruby/lib/ruby/1.9/forwardable.rb:201
run at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-input-file-2.2.5/lib/logstash/inputs/file.rb:294
inputworker at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.2-java/lib/logstash/pipeline.rb:342
start_input at /opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.2-java/lib/logstash/pipeline.rb:336

{:timestamp=>"2016-06-09T20:06:31.928000+0100", :message=>"IdentityMapCodec has reached 80% capacity", :current_size=>19993, :upper_limit=>20000, :level=>:warn}

Please suggest

I have the same issue too:
IdentityMapCodec has reached 100% capacity {:current_size=>20000, :upper_limit=>20000, :level=>:error}
LogStash::Codecs::IdentityMapCodec::IdentityMapUpperLimitException: LogStash::Codecs::IdentityMapCodec::IdentityMapUpperLimitException
visit at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:37
check_map_limits at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:325
record_codec_usage at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:304
stream_codec at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:295
accept at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-codec-multiline-2.0.11/lib/logstash/codecs/identity_map_codec.rb:177
accept at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-input-file-2.2.5/lib/logstash/inputs/file.rb:250
observe_read_file at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:79
each at org/jruby/RubyArray.java:1613
observe_read_file at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:78
loop at org/jruby/RubyKernel.java:1479
observe_read_file at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:74
subscribe at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:39
each at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:187
each at org/jruby/RubyArray.java:1613
each at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:176
each at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:120
call at org/jruby/RubyProc.java:281
synchronized at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:357
synchronize at org/jruby/ext/thread/Mutex.java:149
synchronized at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:357
each at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:118
subscribe at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/watch.rb:280
subscribe at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/filewatch-0.8.1/lib/filewatch/observing_tail.rb:23
subscribe at /app/oracle/logstash-2.3.3/vendor/jruby/lib/ruby/1.9/forwardable.rb:201
run at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-input-file-2.2.5/lib/logstash/inputs/file.rb:294
inputworker at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.3-java/lib/logstash/pipeline.rb:342
start_input at /app/oracle/logstash-2.3.3/vendor/bundle/jruby/1.9/gems/logstash-core-2.3.3-java/lib/logstash/pipeline.rb:336