报错 Unknown setting 'embedded' for elasticsearch

新人一枚，按照书籍一步步操作的时候碰到故障，特来寻求大家帮助
[root@localhost bin]# ./logstash -f ./config.conf 
Settings: Default pipeline workers: 2
Unknown setting 'embedded' for elasticsearch {:level=>:error}
Pipeline aborted due to error {:exception=>"LogStash::ConfigurationError", :backtrace=>["/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.4.0-java/lib/logstash/config/mixin.rb:135:in `config_init'", "/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.4.0-java/lib/logstash/outputs/base.rb:79:in `initialize'", "/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.4.0-java/lib/logstash/output_delegator.rb:74:in `register'", "/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.4.0-java/lib/logstash/pipeline.rb:181:in `start_workers'", "org/jruby/RubyArray.java:1613:in `each'", "/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.4.0-java/lib/logstash/pipeline.rb:181:in `start_workers'", "/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.4.0-java/lib/logstash/pipeline.rb:136:in `run'", "/opt/logstash/vendor/bundle/jruby/1.9/gems/logstash-core-2.4.0-java/lib/logstash/agent.rb:491:in `start_pipeline'"], :level=>:error}
H^Hstopping pipeline {:id=>"main"}
 
————————————————————————————————————
[root@localhost bin]# cat config.conf 
input{
  stdin{}
}

output{
  stdout{
       codec=>rubydebug         
}
  elasticsearch{
    embedded => true
  }
}
[root@localhost bin]#