ohthree/tach — pull request #3 by SandyWalsh (2012-04-06 15:08:04+00:00)
Title: Stacktach

Adds a notifier for sending metrics to StackTach.

Also adds the idea of a Transaction ID to a notifier. When the 'bump_transaction_id = 1' configuration flag is set on a metric the notifiers transaction id is bumped at the start of the metric collection.

The label can have {%TX_ID%} in it, which will be replaced with the transaction id. This maps to routing_key in nova/stacktach.

The motivation is to have a top-level metric "frame" all inner metrics with a consistent transaction id.

For example, you might put the transaction id on the api middleware, but also collect metrics on .api and have them all under the same umbrella.

The logical conclusion to this is to have transaction ID's that span servers ... somehow. But that's an exercise left to the reader.