statsd-plugin doesn't seem to flush

[nina]

Setup:

collectd 5.5 with the statsd-plugin. Statsd and redis counters in the application code via the python API, all called in the same methods.

The statsd counter values get send to Riemann via collectd, the redis counter values directly to log files.

Problem: 

The redis values sent to the logfiles are correct, the values sent to Riemann via collectd are not.

Statsd sends counter values in regular intervals, default 10s, and flushes the buckets to restart counting again for the next time interval.

This does not seem to happen for my statsd counters, instead it seems like the counters are never reset. I can be sure of that because of historical data and the redis logging values

I also build a test with a minute ping on a counter and it just keeps counting up 1,2,3,4 ... instead of sending 1,1,1,1,1,1.

I saw in the collectd source that the statsd-plugin sends these callbacks:

Callbacks={{Callback|config}}, {{Callback|init}}, {{Callback|read}}, {{Callback|shutdown}}

Could it be that the callbacks don't signal the statsd plugin "Thank you for the value please flush now"? Would adding {Callback|flush} solve this issue?

Maybe it's also a collectd caching problem?

Did anyone else encounter counting problems with the statsd plugin? Before switching to collectd I had statsd standalone running on the same servers and it all worked fine.