Yesterday, AdSenseAdvisor posted on WebmasterWorld that there would be an outage for Google AdSense tomorrow, August 9th, between 10AM and 2PM PDT. Ad serving isn't affected but AdSense addicts won't be able to check their accounts.
Usually, these announcement threads go unanswered. This time, though, someone asked the details behind such a maintenance procedure. At first, AdSenseAdvisor gave the generic answer: "our engineers carry out all the tasks required to keep our systems running as they should."
Did the political answer suffice? Not so much. Forum members started speculating what would happen. A good explanation (though purely speculation) was offered by Hobbs, who said:
During maintenance, raw data is redirected from processing into storage mode, this includes all the traffic and clicks logs plus every thing else Google collects, think of it as a huge bucket filling up.
Post maintenance: First a raw data sample is processed and analyzed for consistency, click fraud, earnings .., if all is well the data processing tap is opened and reports start to trickling in till the bucket is empty.
So why can't you access your data? A few reasons are proposed: it may be on hold until this is complete, or if there are any problems, the reports would be inaccurate anyway so Google tries to avoid displaying it until everything looks good again.
Forum discussion continues at WebmasterWorld.