Logstash filter to add a tag if a stack trace is found in the message

logstash_stacktrace_find.conf

filter {
    grep {
      match => [ "message", "(^.+Exception: .+)|(^\s+at .+)|(^at .+)|(^\s+... \d+ more)|(^\s*Caused by:.+)|(^Caused by:.+)" ]
      add_tag => [ "has_stacktrace" ]
    }
}