riemann flapping

riemann.clj

(udp-server {:host "::"})

(periodically-expire 1)

(let [index (index)]

  (streams
    index
    (match :service #"^serf"
           (changed-state {:init "ok"}
                          (stable 20 :state 
                                  prn))))
)

riemann.log

#riemann.codec.Event{:host "ch01", :service "serf", :state "ok", :description "ch01 is reachable", :metric nil, :tags nil, :time 1450783205, :ttl 20.0}
{:time 290156645199/200, :state "expired", :service "serf", :host "ch01"}

riemman-alert.rb

require 'riemann/client'

r = Riemann::Client.new
                      
default = {:host => 'ch01', :description => "ch01 is reachable", :metric => nil, :service => "serf", :ttl => 20}

r << default.merge(:state => 'critical', :description => "ch01 is not reachable").tap { |p| puts p }
sleep(2)
r << default.merge(:state => 'ok', :description => "ch01 is reachable").tap { |p| puts p }