Thanks for the info, both your points can explain the anomalies I saw.
The mirroring issue can explain the reason why I see many *.mp3 and .*_ep titles in the pagecounts files that do not correlate to any Wikipedia page, probably spammers monetizing music.
How can I help resolving these issues?
> On Mar 9, 2015, at 23:30, analytics-request(a)lists.wikimedia.org wrote:
>
> Re: Anomalies in pagecounts files?