Define the statistics service in the domain, where the httpd is running.

[httpdDomain]
[httpdDomain/httpd]
...
[httpdDomain/statistics]

The statistics service automatically creates a directory tree, structured according to years, months and days.

Once per hour, a total.raw file is produced underneath the active year, month and day directories, containing the sum over all pools and storage classes of the corresponding time interval. The day directory contains detailed statistics per hour and for the whole day.

/opt/d-cache/statistics/YYYY/total.raw
/opt/d-cache/statistics/YYYY/MM/total.raw
/opt/d-cache/statistics/YYYY/MM/DD/total.raw
/opt/d-cache/statistics/YYYY/MM/DD/YYYY-MM-DD-day.raw
/opt/d-cache/statistics/YYYY/MM/DD/YYYY-MM-DD-HH.raw

In the same directory tree the HTML files are created for each day, month and year.

/opt/d-cache/statistics/YYYY/index.html
/opt/d-cache/statistics/YYYY/MM/index.html
/opt/d-cache/statistics/YYYY/MM/DD/index.html

By default the path for the statistics data is /var/lib/dcache/statistics. You can modify this path by setting the property dcache.paths.statistics to a different value.