[$]> cat gather
    #!/bin/bash -e
    
    http "http://graphite.endpoint.com/render?from=00%3A00_20130614&until=23%3A30_20130614&target=$1&format=csv" |
    awk -F , '{print $3}' |
    average

The smallest granularity we store in Graphite is 10s means, which is usually good enough, but could be a little misleading in this situation.  I originally tried doing the median through graphite, but it's hard to get the endpoints and the range to line up, so it was easier to just pull all the data out through the text api and calculate it elsewhere.

We should be able to do the 90% interval without too much trouble.