Getting warning in Nohup.out file for logstash

Elastic Stack Logstash
1

Hi Experts,

I am getting below message on my logstash server . I am using LS1.5.4 version .Please suggest what it is and how i can remove or resolve this problem?

{:timestamp=>"2016-02-04T16:27:14.292000+0530", :message=>"Failed to flush outgo ing items", :outgoing_count=>1, :exception=>"Manticore::ClientProtocolException" , :backtrace=>["/opt/ls/logstash-1.5.4/vendor/bundle/jruby/1.9/gems/manticore-0. 4.4-java/lib/manticore/response.rb:35:in initialize'", "org/jruby/RubyProc.java :271:in call'", "/opt/ls/logstash-1.5.4/vendor/bundle/jruby/1.9/gems/manticore- 0.4.4-java/lib/manticore/response.rb:70:in call'", "/opt/ls/logstash-1.5.4/vend or/bundle/jruby/1.9/gems/manticore-0.4.4-java/lib/manticore/response.rb:245:in call_once'", "/opt/ls/logstash-1.5.4/vendor/bundle/jruby/1.9/gems/manticore-0.4. 4-java/lib/manticore/response.rb:148:in code'", "/opt/ls/logstash-1.5.4/vendor/ bundle/jruby/1.9/gems/elasticsearch-transport-1.0.12/lib/elasticsearch/transport /transport/http/manticore.rb:71:in perform_request'", "org/jruby/RubyProc.java: 271:in call'", "/opt/ls/logstash-1.5.4/vendor/bundle/jruby/1.9/gems/elasticsear ch-transport-1.0.12/lib/elasticsearch/transport/transport/base.rb:190:in /elasticsearch.rb:541:in lasticsearch-1.0.7-java/lib/logstash/outputs/elasticsearch.rb:531:in receive'", "/opt/ls/logstash-1.5.4/vendor/bundle/jruby/1.9/gems/logstash-core-1.5.4-java/l ib/logstash/outputs/base.rb:88:in handle'", "/opt/ls/logstash-1.5.4/vendor/bund le/jruby/1.9/gems/logstash-core-1.5.4-java/lib/logstash/outputs/base.rb:79:in w orker_setup'"], :level=>:warn}