Update: You can now configure your logging and metrics via the portal as described here.
Windows Azure Storage Analytics offers you the ability to track, analyze, and debug your usage of storage(Blobs, Tables and Queues). You can use this data to analyze storage usage to improve the design of your applications and their access patterns to Windows Azure Storage. Analytics data consists of:
This feature provides a trace of all executed requests for your storage accounts as block blobs in a special container called $logs. Each log entry in the blob corresponds to a request made to the service and contains information like request id, request URL, http status of the request, requestor account name, owner account name, server side latency, E2E latency, source IP address for the request etc.
This data now empowers you to analyze your requests much more closely. It allows you to run the following types of analysis:
Provide summary of key statistics for Blobs, Tables and Queues for a storage account. The statistics can be categorized as:
All Analytics Logs and Metrics data are stored in your user account and is accessible via normal Blob and Table REST APIs. The logs and metrics can be accessed from a service running in Windows Azure or directly over the Internet from any application that can send and receive HTTP/HTTPS requests. You can opt in to store either the log data and/or metric data by invoking a REST API to turn on/off the feature at a per service level. Once the feature is turned on, the Windows Azure Storage stores analytics data in the storage account. Log data is stored as Windows Azure Blobs in a special blob container and metrics data is stored in special tables in Windows Azure Tables. To ease the management of this data, we have provided the ability to set a retention policy that will automatically clean up your analytics blob and table data.
Please see the following links for more information:
Windows Azure Storage Team
Will storage analytics and metrics get tracked for hits against the CDN, or only against an actual storage account? e.g. if a request can be served from the CDN and doesn't require a refresh, would I see anything in the logs, or only if the CDN actually had to fetch the blob?
When the Azure CDN access your storage account (e.g., when the TTL expires), that request will be logged inside of the storage account. The hits at the Azure CDN edges are not logged as part of the storage account (only the requests that directly hit the storage account). So you won’t see logging/metrics for Azure CDN hits as part of the storage account’s logging/metrics. Note, the Azure CDN team is looking at providing logging for requests coming into Azure CDN in the future.