Logstash is dying with an Exception

[Ashish_Khare]

Hello,

I am running my logstash with 20g of jvm memory. But suddenly logstash is dying with following exception :

Oct 29 09:54:11 prod-1-ap-southeast-1b-elk-node-006 logstash: [ERROR] 2018-10-29 09:54:11.708 [Ruby-0-Thread-145@[main]>worker7: /usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:384] pipeline - Exception in pipelineworker, the pipeline stopped processing new events, please check your filter configuration and restart Logstash. {:pipeline_id=>"main", "exception"=>"undefined method to_hash_with_metadata' for nil:NilClass", "backtrace"=>["/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-filter-multiline-3.0.4/lib/logstash/filters/multiline.rb:273:in block in merge'", "org/jruby/RubyArray.java:1734:in each'", "org/jruby/RubyEnumerable.java:936:in inject'", "/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-filter-multiline-3.0.4/lib/logstash/filters/multiline.rb:272:in merge'", "/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-filter-multiline-3.0.4/lib/logstash/filters/multiline.rb:230:in previous_filter!'", "/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-filter-multiline-3.0.4/lib/logstash/filters/multiline.rb:173:in filter'", "/usr/share/logstash/logstash-core/lib/logstash/filters/base.rb:145:in do_filter'", "/usr/share/logstash/logstash-core/lib/logstash/filters/base.rb:164:in block in multi_filter'", "org/jruby/RubyArray.java:1734:in each'", "/usr/share/logstash/logstash-core/lib/logstash/filters/base.rb:161:in multi_filter'", "/usr/share/logstash/logstash-core/lib/logstash/filter_delegator.rb:47:in multi_filter'", "(eval):129554:in block in initialize'", "org/jruby/RubyArray.java:1734:in each'", "(eval):129551:in block in initialize'", "(eval):20297:in block in filter_func'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:447:in filter_batch'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:426:in worker_loop'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:385:in block in start_workers'"], :thread=>"#<Thread:0x5bd35d3c@/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:246 sleep>"} Oct 29 09:54:11 prod-1-ap-southeast-1b-elk-node-006 logstash: [FATAL] 2018-10-29 09:54:11.772 [LogStash::Runner] runner - An unexpected error occurred! {:error=>#<NoMethodError: undefined method to_hash_with_metadata' for nil:NilClass>, :backtrace=>["/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-filter-multiline-3.0.4/lib/logstash/filters/multiline.rb:273:in block in merge'", "org/jruby/RubyArray.java:1734:in each'", "org/jruby/RubyEnumerable.java:936:in inject'", "/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-filter-multiline-3.0.4/lib/logstash/filters/multiline.rb:272:in merge'", "/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-filter-multiline-3.0.4/lib/logstash/filters/multiline.rb:230:in previous_filter!'", "/usr/share/logstash/vendor/bundle/jruby/2.3.0/gems/logstash-filter-multiline-3.0.4/lib/logstash/filters/multiline.rb:173:in filter'", "/usr/share/logstash/logstash-core/lib/logstash/filters/base.rb:145:in do_filter'", "/usr/share/logstash/logstash-core/lib/logstash/filters/base.rb:164:in block in multi_filter'", "org/jruby/RubyArray.java:1734:in each'", "/usr/share/logstash/logstash-core/lib/logstash/filters/base.rb:161:in multi_filter'", "/usr/share/logstash/logstash-core/lib/logstash/filter_delegator.rb:47:in multi_filter'", "(eval):129554:in block in initialize'", "org/jruby/RubyArray.java:1734:in each'", "(eval):129551:in block in initialize'", "(eval):20297:in block in filter_func'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:447:in filter_batch'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:426:in worker_loop'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:385:in block in start_workers'"]}`

Can you please help ?