Grok pattern for custom response time in ns, us, ms or s - logstash - logstash-grok

Question

I need to parse a response time from the custom log format so it can go via Logstash pipeline to elastic.
Example log entry be:
2018-11-19 23:40:00-0500 avg:30.5ms max:135ms min:6.61ms reqs:20 rsps:20 errs:0 maxcon:3 99th:135ms 95th:134ms 90th:111ms 75th:22.6ms 50th:15.6ms heap:36.7% load:1.43/0.75/0.60 cpu:26.3%
Avg, max, min can be in ns, us, ms or s format.
I have started from:
%{TIMESTAMP_ISO8601:timestamp} avg:%{NUMBER:avg}ms
of course it won't work for ns etc. so I will need something like:
%{TIMESTAMP_ISO8601:timestamp} avg:%{NUMBER:avg}(ns|us|ms|s)
However I will lose infomration as I have to scale of of values to say ms. So ns multiply by 1e6, ms -> 1e3, ms -> 1, s -> 1e-3.
What is the best approach to solve that issue?

Answer 1

Ok so I have found a solution finally.
First a bit of a change for the grok pattern as follows:
%{TIMESTAMP_ISO8601:timestamp} avg:%{NUMBER:avg:float}(?<avgUnit>[unm]?s)
That gives us two elements in the event 'avg' and 'avgUnit' such values can be passed to the ruby script which is executed by plugin:
The script read as flows:
# filter runs for every event
# # return the list of events to be passed forward
# # returning empty list is equivalent to event.cancel
def filter(event)
#convert operates on event
convert(event ,"maxUnit", "max")
convert(event, "minUnit", "min")
convert(event, "avgUnit", "avg")
convert(event, "99thUnit", "99th")
return [event]
end
def convert(event, unitField, valueField)
if event.get(valueField).nil?
event.tag("__#{valueField}__not_found")
return [event]
end
if event.get(unitField).nil?
event.tag("__#{unitField}_not_found")
return [event]
end
unit = event.get(unitField)
value = event.get(valueField)
fieldName = "#{valueField}InMs"
case unit
when "ns"
event.set(fieldName, value / 1.0e6)
when "us"
event.set(fieldName, value / 1.0e3)
when "ms"
event.set(fieldName, value)
when "s"
event.set(fieldName, value * 1.0e3)
else
event.tag("__not_supported_unit_#{unit}")
end
return [event]
end
Pipeline must have configuration to include a script after match:
grok {
match => {
"message" => ["%{TIMESTAMP_ISO8601:tstamp} avg:%{NUMBER:avg:float}(?<avgUnit>[unm]?s)]
}
}
ruby {
path => "script.rb"
}