logstash 启动异常。报错的是jruby相关内容

[2018-02-23T05:19:53,528][FATAL][logstash.runner ] An unexpected error occurred! {:error=>#<NoMethodError: undefined method `<' for nil:NilClass>, :backtrace=>["/home/env/logstash-6.2.1/vendor/bundle/jruby/2.3.0/gems/logstash-output-elasticsearch-9.0.2-java/lib/logstash/outputs/elasticsearch/common.rb:213:in `get_event_type'", "/home/env/logstash-6.2.1/vendor/bundle/jruby/2.3.0/gems/logstash-output-elasticsearch-9.0.2-java/lib/logstash/outputs/elasticsearch/common.rb:165:in `event_action_params'", "/home/env/logstash-6.2.1/vendor/bundle/jruby/2.3.0/gems/logstash-output-elasticsearch-9.0.2-java/lib/logstash/outputs/elasticsearch/common.rb:39:in `event_action_tuple'", "/home/env/logstash-6.2.1/vendor/bundle/jruby/2.3.0/gems/logstash-output-elasticsearch-9.0.2-java/lib/logstash/outputs/elasticsearch/common.rb:34:in `block in multi_receive'", "org/jruby/RubyArray.java:2486:in `map'", "/home/env/logstash-6.2.1/vendor/bundle/jruby/2.3.0/gems/logstash-output-elasticsearch-9.0.2-java/lib/logstash/outputs/elasticsearch/common.rb:34:in `multi_receive'", "/home/env/logstash-6.2.1/logstash-core/lib/logstash/output_delegator_strategies/shared.rb:13:in `multi_receive'", "/home/env/logstash-6.2.1/logstash-core/lib/logstash/output_delegator.rb:49:in `multi_receive'", "/home/env/logstash-6.2.1/logstash-core/lib/logstash/pipeline.rb:479:in `block in output_batch'", "org/jruby/RubyHash.java:1343:in `each'", "/home/env/logstash-6.2.1/logstash-core/lib/logstash/pipeline.rb:478:in `output_batch'", "/home/env/logstash-6.2.1/logstash-core/lib/logstash/pipeline.rb:430:in `worker_loop'", "/home/env/logstash-6.2.1/logstash-core/lib/logstash/pipeline.rb:385:in `block in start_workers'"]}
[2018-02-23T05:19:53,843][ERROR][org.logstash.Logstash ] java.lang.IllegalStateException: org.jruby.exceptions.RaiseException: (SystemExit) exit
[root@localhost bin]#