logstash - multiple filter workers

00-config

input {
    stdin {
        type => "zeus"
    }
}

filter {
    grok {
        type => "zeus"
        pattern => "%{IP:ip} %{HOST:host} %{USER:user} \[%{HTTPDATE:timestamp}\] \"%{WORD:verb} %{URIPATHPARAM:request} HTTP/%{NUMBER:httpversion}\" %{NUMBER:response} (?:%{NUMBER:bytes}|-) \"(?:%{URI:referrer}|-)\" %{QS:agent} \"%{GREEDYDATA:cookie}\" %{QS:ssl} node_s:(?:%{NUMBER:node_time}|-) req_s:(?:%{NUMBER:req_time}|-) retries:(?:%{NUMBER:retries}|-)"
        named_captures_only => true
    }
}

output {
    stdout { }
}

output

0 carrera(~/l/logstash) % time ruby --1.9 bin/logstash agent -f etc/r.conf < sample.log >/dev/null
...
ruby --1.9 bin/logstash agent -f etc/r.conf < sample.log > /dev/null  192.77s user 4.45s system 137% cpu 2:23.19 total


0 carrera(~/l/logstash) % time ruby --1.9 bin/logstash agent -w 2 -f etc/r.conf 
< sample.log >/dev/null
...
ruby --1.9 bin/logstash agent -w 2 -f etc/r.conf < sample.log > /dev/null  204.74s user 3.98s system 270% cpu 1:17.19 total

0 carrera(~/l/logstash) % time ruby --1.9 bin/logstash agent -w 3 -f etc/r.conf < sample.log >/dev/null
...ruby --1.9 bin/logstash agent -w 3 -f etc/r.conf < sample.log > /dev/null  195.79s user 4.03s system 390% cpu 51.219 total

0 carrera(~/l/logstash) % time ruby --1.9 bin/logstash agent -w 6 -f etc/r.conf < sample.log >/dev/null
...
ruby --1.9 bin/logstash agent -w 6 -f etc/r.conf < sample.log > /dev/null  247.96s user 7.46s system 519% cpu 49.173 total