Simple stream objects for working with Carbon (Graphite) streams.
I need to implement a simple metric key mangler for my Graphite infrastructure. collectd is great for capturing metrics, but the paths are a bit verbose. For example, I think the following make a little more sense:
collectd.my-host.cpu.0.cpu.idle.value → collectd.my-host.cpu.0.idle
collectd.my-host.df.df.boot.free → collectd.my-host.df.boot.free
collectd.my-host.interface.if_errors.eth0.rx → collectd.my-host.interface.eth0.rx.errors
collectd.my-host.interface.if_octets.eth0.rx → collectd.my-host.interface.eth0.rx.octets
collectd.my-host.interface.if_packets.eth0.rx → collectd.my-host.interface.eth0.rx.packets
You might also want to derive a hierarchy from a well-structured hostname. Instead of usw2a-dev-webserver-01 you could do dev.usw2a.webserver-01. Or you could drop a metric entirely.
Some of this can be implemented with Carbon's own rewrite-rules.conf, but those are fairly limited to prefix/suffix mangling. I'm also gnawing on the idea of building a simple pub/sub mechanism with ZeroMQ so that subscribers can receive metric values in real-time, as well as notifications of metric lifecycle events (a new host comes online, or stops updating).
There's only one example right now, bit it shows how you can create a simple metric rewriter by implementing a stream.Transform instance.