A stream-processing service for monitoring distributed clusters.

Inspired by Riemann, dmon will use Python coroutines as its stream-processing language. An example configuration will look something like:

stream = when(lambda event: event['state'] == "warning",
              email("me@mycompany.com"))

To start a dmon server, you'll first need to write a Python module with your streams in it. A stream is just a co-routine that receives events ("is yielded into"), does some processing, and sends the events to one or more streams. Bind your streams at the module level to names containing the word, "stream". Then tell dmon about where it can import your module and it'll handle the rest:

$ export PYTHONPATH="/path/to/my/module:$PYTHONPATH"
$ export DMON_STREAM_MODULE="mystream"
$ cd /to/my/dmon/env && source bin/activate && python dmon/dmon/dmon.py

That should get the UDP listener up and ready to receive events.

For development purposes I've implemented the most rudimentary protocol possible: JSON. I plan to eventually add Protocol Buffers (and maybe Thrift) support in the future.

An event message has the following keys:

• host
• service
• state
• description
• time
• ttl
• metric

And all fields are required. This will change in the future as I intend to mirror Riemann's event protocol which allows fields to be optional.

To run the unit tests:

$ python setup.py test

• protocol
  • protobuf
  • thrift ?
  • jsonschema ?
• stream processing
• event storage / querying
• web socket support