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Julien:
	I checked the IRC log yesterday and also patch from Angus (https://github.com/asalkeld/ceilometer/commit/c678ff8abd2a91c4404657748b9ed9b31c1541df ), I'm a bit confused.

	From Angus's patch and the discussion, IIUC, all data will be stored as meter in the storage, and the API handler will translate from meter to CW format (dimensions, Namespace, unit etc). This is a different to my understanding, so I want to get the big picture of monitor support and multiple publisher.

	Firstly , some background clarification. I think currently when we talking about monitor, we are mostly talking about CW support, or CW-similar support, when we talking about multiple publisher, we are talking about CW publisher, at least in the near future (like in H range). Am I right?

	Then, in my original understanding, in CW/monitor usage, the raw data collected from pollsters will be translated into CW format (MetricName, Namespace, Dimensions, Unit, Value) and we will provide the Metrics provided by AWS. 

	Also I envision the CW data will be stored in the storage, with a dimensions table, and CW data in another table. Each (metricname+dimensions) combination will have an entry on the dimension table. A table for the alarm, and alarm table will be updated when new data added.

 	The aggregation will be achieved through passing dimensions as a filter parameter to the query.

	With this envision, the translation from Counter to CW data will happen in publisher, and we may need various type of transformer to achieve it, including a) Unit translation like from kb to byte, b) interval translation like from 10s to 60s, c) aggregation like summary all vnic data into one network in/out CW data, d) translate Counter format to CW data format, e) delta calculation like the CPU utilization. And we deserve the transformer mechanism to achieve them.

	However, if we will achieve CW data from API side (that also make sense and seems more flexible), then I don't think any transformer needed, except the CPU utilization, which has been implemented already. The interval in fact does not matter in such situation, except the interval of the pollster.

	Possibly I lost something important, or we will have more publisher to support in near future other than CW?

Thanks
--jyh