If you want to measure the performance of Logstash, Metrics plugin is way to go. The syntax given in the documentation(Documentation Link) does not work which is given below.
if "metric" in [tags] { stdout { message => "rate: %{events.rate_1m}" } }
The correct syntax with working Logstash configuration is given below.
input { #Input Filters } filter { metrics { meter => "events" add_tag => "metric" } #Other Filters } output { if "metric" in [tags] { stdout { codec => line { format => "Rate: %{events.rate_1m}" } } } stdout { codec => rubydebug } }