How to store composite key data in HBase/bigtable?

In google's Bigtable paper, It descripted the bigtable structure.

The table schema is like this.

Table(url<key>, contents, anchor:cnnsi.com, anchor:my.look.ca") 

Columns can add dynamically.

My question is: Take the google analytics for example, I want to know which brower the people use to surf mysite.

So the table schema is Table(web_site_id<key>, visit_time<ke开发者_运维技巧y>, os_type<key>, brower_type<key>, visit_times).

First I want to known in a time period how many people visit my site?

Second I want to know in a period the how many people use chrome/firefox to visit my site?

Third I want to know how man people who use windows os use firefox to visit my site?

How can I do this by using bigtable/hbase.

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You should check how mozilla does it : BouncerRealTimeMetricsProject, glow. And since it's a timeseries problem you should also check opentsdb.