Smokeping-like tcp connectivity tester, reports to statsd so you get aggregate statistics into graphite. Written in Golang.
Create a "targets" file that looks like:
<host>:<port>
<host>:<port>
then just go build smoketcp.go and ./smoketcp <statsd_host>:<statsd_port> and boom.
Every second it tests every entry (in parallel), and reports errors and time-to-connection to statsd. Statsd then aggregates across the flushInterval (in our case 60s) and stores in graphite per target the errors rate, and the mean, lower, upper, upper_90 etc values.