Data Platform/Data Lake/Traffic/Caching

This dataset is a restricted public snapshot of the wmf.webrequest table intended for caching research.
The most recent release is composed of caching data for:
# upload (image) web requests from one CDN cache server of upload.wikimedia.org, Wikimedia Commons, and
# text (HTML pageview) web requests from one CDN cache server of Wikipedia.
== Data Updates & Format ==
The data is updated manually upon request.
The current release of this data, released in November 2019, is available at https://analytics.wikimedia.org/published/datasets/caching/2019/. It was released as a set of gzip-compressed tsv files. It includes a total of 42 compressed files, 21 upload data files and 21 text data files. The request for the most recent release of this data can be found at phab:T225538.
=== Upload Data ===
Each upload data file, denoted cache-u, contains exactly 24 hours of consecutive data. These files are each roughly 1.5GB in size and hold roughly 4GB of decompressed data each.
Each decompressed upload data file has the following columns:
Column Name 	Data Type	Notes
relative_unix 	int 	Seconds since start timestamp of dataset
hashed_path_query	bigint 	Salted hash of path and query of request
image_type 	string 	Image type from Content-Type header of response
response_size 	int 	Response size in bytes
time_firstbyte 	double 	Seconds to first byte
=== Text Data ===
Each text data file, denoted cache-t, contains exactly 24 hours of consecutive data. These files are each roughly 100MB in size and hold roughly 300MB of decompressed data each.
Each decompressed upload data file has the following columns:
Column Name 	Data Type	Notes
relative_unix 	int 	Seconds since start timestamp of dataset
hashed_host_path_query	bigint 	Salted hash of host, path, and query of request
response_size 	int 	Response size in bytes
time_firstbyte 	double 	Seconds to first byte
== Privacy ==
Since this data has many privacy concerns, this public release applies several changes to make the data reveal less while providing value for a public audience.
=== Relative timestamps ===
This data employs a unique timing paradigm. The relative_unix field is equal to the seconds that have elapsed between the timestamp at which the web request occurred and a fixed randomly-selected start timestamp. This standard makes it significantly more difficult for bad actors to map this data to other publicly-released WMF data sets while maintaining the utility of timestamps for caching research as a means to determine the frequencies of these web requests.
=== Hashed host, path, and query ===
We securely hash the host, path, and query fields of the web requests with a salt to effectively anonymize the content. This both makes it more difficult to map this data between data sets and minimizes the general privacy concerns related to the combination of content, timestamps, and content sizes.
== Risk Assessment ==
== Previous Releases ==
=== 2016 ===
Release: analytics.wikimedia.org
Request: T128132
Description: A more detailed, but more privacy-conscious iteration of the 2007 release between July 1st, 2016 and July 10th, 2016
Fields: hashed host and path, uri query, content type, response size, time to first byte, X-Cache
=== 2008 ===
Release: wikibench.eu
Description: A trace of 10% of all user requests issued to Wikipedia in all languages between September 19th, 2007 and January 2nd, 2008
Fields: request count, unix timestamp, request url, database update flag
Category:Traffic data
Category:Data platform