Pipeline aborted due to error PatternError.pattern not defined

[SashaAlex]

In my project I run logstash as service.But it gives following error.
how to correct this
[2018-03-28T07:03:03,652][ERROR][logstash.agent ] Pipeline aborted due to error {:exception=>#<Grok::PatternError: pattern %{VAMPS_ACCESS_LOG} not defined>, :backtrace=>["/usr/share/logstash/vendor/bundle/jruby/1.9/gems/jls-grok-0.11.4/lib/grok-pure.rb:123:in compile'", "org/jruby/RubyKernel.java:1479:inloop'", "/usr/share/logstash/vendor/bundle/jruby/1.9/gems/jls-grok-0.11.4/lib/grok-pure.rb:93:in compile'", "/usr/share/logstash/vendor/bundle/jruby/1.9/gems/logstash-filter-grok-4.0.2/lib/logstash/filters/grok.rb:281:inregister'", "org/jruby/RubyArray.java:1613:in each'", "/usr/share/logstash/vendor/bundle/jruby/1.9/gems/logstash-filter-grok-4.0.2/lib/logstash/filters/grok.rb:275:inregister'", "org/jruby/RubyHash.java:1342:in each'", "/usr/share/logstash/vendor/bundle/jruby/1.9/gems/logstash-filter-grok-4.0.2/lib/logstash/filters/grok.rb:270:inregister'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:290:in register_plugin'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:301:inregister_plugins'", "org/jruby/RubyArray.java:1613:in each'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:301:inregister_plugins'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:311:in start_workers'", "/usr/share/logstash/logstash-core/lib/logstash/pipeline.rb:235:inrun'", "/usr/share/logstash/logstash-core/lib/logstash/agent.rb:408:in `start_pipeline'"]}

[atira (Attila Boncok)]

The log tells you the exact problem:

@SashaAlex

Grok::PatternError: pattern %{VAMPS_ACCESS_LOG} not defined

In your Logstash Grok filter you are referring to a custom pattern you haven't defined.
You need to tell Grok filter the directory where it can find the custom patterns. The property is called patterns_dir. See here.