Analytics/Data Lake/Traffic/Webrequest

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wmf.webrequest and wmf_raw.webrequest within the Wikimedia Foundation's pageview data pipeline (Hive/Hadoop is the rounded box at the bottom)

The webrequest datasets contain logs of all the hits to the WMF's servers (specifically, the Varnish servers). This includes requests for page HTML, images, CSS, and Javascript, as well as requests to the API.[1] For privacy reasons, this data is purged after 90 days.

There are two webrequest tables available on Hive. The wmf_raw.webrequest table is JSON data directly imported from Kafka. wmf.webrequest contains the 'refined' webrequest data. The raw table is purged more frequently than 90 days.

For many purposes, it is preferable to instead query the much smaller tables pageview_hourly or projectview_hourly, which contain 'pre-aggregated' webrequest data, filtered to keep only pageviews, and aggregated over a predefined set of dimension.

wmf.webrequest

The wmf.webrequest table is 'refined' webrequest data. It contains the same data as the wmf_raw.webrequest, as well as additional information that has been added during the refinement phase. It is stored in the Parquet format. Parquet is a column-based data storage format. When querying wmf.webrequest, Hive will not have to parse JSON, and it will only have to read in data from disk for columns that you are explicitly using in your query. This should increase performance of most Hive queries. See Data Format Experiments#Results for more info.

Current Schema

col_name data_type comment
hostname string Source node hostname
sequence bigint Per-host sequence number
dt string Timestamp at cache in ISO 8601 format
time_firstbyte double Time to first byte
ip string IP of packet at cache
cache_status string Cache status
http_status string HTTP status of response
response_size bigint Response size
http_method string HTTP method of request
uri_host string Host of request
uri_path string Path of request
uri_query string Query of request
content_type string Content-Type header of response
referer string Referer header of request
x_forwarded_for string X-Forwarded-For header of request
user_agent string User-Agent header of request
accept_language string Accept-Language header of request
x_analytics string X-Analytics header of response, looks like: ns=-1;special=Userlogin;WMF-Last-Access=09-May-2017;WMF-Last-Access-Global=09-May-2017;https=1
range string Range header of response
is_pageview boolean Indicates if this record was marked as a pageview during refinement
record_version string Keeps track of changes in the table content definition
client_ip string Best guess client IP address from the X-Client-IP header, set by varnish using X-Forwarded-For and other information.
geocoded_data map<string,string> Geocoded data computed during refinement using client_ip and MaxMind database contains: continent, country_code, country, subdivision, city but has nulls where information is not available
x_cache string X-Cache header of response
user_agent_map map<string,string> User-agent map with browser_family, browser_major, device_family, os_family, os_major, os_minor and wmf_app_version keys and associated values
x_analytics_map map<string,string> X_analytics map view of the x_analytics field
ts timestamp Unix timestamp in milliseconds extracted from dt
access_method string Method used to accessing the site (mobile app|mobile web|desktop)
agent_type string Categorise the agent making the webrequest as either user or spider (automatas to be added).
is_zero boolean Indicates if the webrequest is accessed through a zero provider
referer_class string Indicates if a referer is internal, external or unknown.
normalized_host struct<

project_class:string, project_family:string,

project:string, qualifiers:array<string>,

tld:string >

struct containing project_class/project_familly (such as wikipedia or wikidata for instance - project_class is to be deprecated, use project_family instead), project (such as en or commons), qualifiers (a list of in-between values, such as m and/or zero) and tld (org most often)
pageview_info map<string,string> map containing project, language_variant and page_title values only when is_pageview = TRUE.
page_id int MediaWiki page_id for the page served by this webrequest. This is not set for pages requested through the MediaWiki API. For MediaWiki redirects, this is set to the redirected-to page_id, i.e. the page_id of the content shown to the user, not the page_id of the originally requested title.
namespace_id int MediaWiki namespace_id for the page served by this webrequest. This is set with the same logic as page_id.
tags array<string> List containing tags qualifying the request, ex: [portal, wikidata]. Will be used to split webrequest into smaller subsets.
webrequest_source string Source cluster (partition field)
year int Unpadded year of request (partition field)
month int Unpadded month of request (partition field)
day int Unpadded day of request (partition field)
hour int Unpadded hour of request (partition field)
Example query

Note the webrequest_source, year, month, day, and hour fields. These are Hive partitions, and are explicit mappings to hourly imports in HDFS. You must include at least one partition predicate in the where clause of your queries (even if it is just year > 0). Partitions allow you to reduce the amount of data that Hive must parse and process before it returns you results. For example, if are only interested in data during a particular day, you could add where year = 2014 and month = 1 and day = 12. This will instruct Hive to only process data for partitions that match that partition predicate. You may use partition fields as you would any normal field, even though the field values are not actually stored in the data files.

Changes and known problems since 2015-03-04

See also m:Research:Page view#Change log for changes to the page view definition itself
Date from Date until Task record_version Details
2015-01-01 * Create table with data from 'text', 'mobile' and 'upload' request sources.
2015-01-26 * Add 'misc' request source.
2015-02-12 * Add 'bits' request source.
2015-02-27 task T90725, task T89401 0.0.1 Add record_version, client_ip and geocoded_data fields to the schema. An error is raised when trying to access those fields for data before the release date.
2015-03-30 task T91749, task T91793, task T89396 0.0.2 Add x_cache, user_agent_map and x_analytics_map fields to the schema. An error is raised when trying to access those fields for data before the release date. Note: user_agent_map and x_analytics_map are to replace original user_agent and x_analytics fields, but field replacement breaks schema backward compatibility. We will deploy this chamge when we'll be confident enough that no more backward incompatible change are needed soon.
2015-04-10 task T95178, task T94584 0.0.3 Add ts, access_method, agent_type and is_zero fields to the schema. An error is raised when trying to access those fields for data before the release date. Note: The agent_type on.y contains spider and user values for the moment. A detailed analysis on user_agent and usage patterns should be overtaken to provide new/refined values.
Warning Warning: [agent_type field is bugged in this version and is fixed in 0.0.4.]
2015-05-07 0.0.4 Add referer_class field to the schema, with possible values internal, external or unknown. An error is raised when trying to access those fields for data before the release date. Agent_type bug is corrected, and some improvements are made in the computation of is_pageview and access_method fields.
2015-06-11 task T99932, task T99918, task T96044 0.0.5 Add normalized_host and pageview_info fields to the schema, and update user_agent_map adding wmf_app_version. normalized_host is created splitting the uri host as a struct with project_class (wikipedia, wikidata for instance), project (en, commons for instance), qualifiers (an array of in-between qualifiers, like m or zero for instance), and tld (org most of the time). pageview_info is set only when is_pageview is true, and is a map with keys project (en.wikipedia, commons.wikimedia for instance), language_variant (zh-hant for instance), and page_title when possible.
2015-08-13 task T107764, task T108833, task T108717 0.0.6 Correct bug in the use of webrequest uri hosts to compute if pageview or not. The change affect 0.2% of pageviews by removing false positives. The 'bits' webrequest_source partition and associated automatic jobs have been removed (every data that was in bits is now text partition), and a new 'maps' webrequest_source partition has been created (data for this partition starts on 2015-08-11T00:00:00).
2015-08-03, 2015-08-10 task TT106581 Two separate Kafka upgrade attempts caused significant data loss. A bug in Kafka caused data not to be compressed properly. Once the bug was fixed, we spent a lot of time patching and repairing what data we could. Several hourly webrequest partitions had significant loss and could not be restored. This loss was either caused by Kafka being too overloaded to accept produce requests, or by a recovery attempt in which a single broker for whom no replicas were in sync was restarted.
Webrequest los 2015-08.png
http://debugging.wmflabs.org/#refinery-graphs-tab. See also: Incident_documentation/20150803-Kafka,Incident_documentation/20150810-Kafka
2015-08-27 task T109256, task T108866 0.0.7 Correct two bugs:
  • In is_pageview definition: outreach.wikimedia.org and donate.wikimedia.org are not pageviews anymore.
  • In page_title extraction (for pageview_info['page_title']): Consistently convert spaces into underscores (only special cases where correctly treated before).
2015-08-31 0.0.8 arbcom-*.wikimedia.org are not pageviews anymore.
2015-09-16 task T109383, task T106134, task T108598 0.0.9 Update ua-parser to an up-to-date version (better user-agent classification), improve spider tagging by enhancing the regular expression used in addition of ua-parser, update pageview definition to prevent requests having 'preview' set in x_analytics header to be counted as pageviews or appPageviews.
2015-11-19 task T119054 0.0.10 Improve spider tagging adding user agent being .*http.* flagged as spider.
2015-12-01 task T116023 0.0.11 Add the mediawiki page_id for this hit when available. For redirects this could be the page_id of the redirect or the page_id of the target. This may not always be set, even if the page is actually a pageview. Upgrade pageview_definition to better filter non-interesting path.
2015-12-15 There was an irrecoverable raw_webrequest data loss for the hour 17 UTC of: 25.6% (misc), 19.5% (mobile), 19.1% (text), 39.1% (upload). the loss was due to the enabling of IPSec. This encrypts varniskafka traffic between caches in remote datacenters and the Kafka brokers in eqiad. During a period of about 40ish minutes, no webrequest logs from remote datacenters were successfully produced to Kafka.
2015-12-18 There was another irrecoverable raw_webrequest data loss between 21:54 and 22:15. A puppet change was merged in which an important firewall rule dealing with IPSec was lost. This kept all varnishkafkas in remote datacenters from producing to Kafka during this time.
2016-02-03 task T115919 0.0.12 Referer classification has an updated version providing external search engine details (when any).
2016-03-09 task T125731 0.0.13 Improve spider tagging regular expression to match the bots that follow the conventions specified in https://meta.wikimedia.org/wiki/User-Agent_policy. Remove tagging user agents containing "WikimediaBot" as bot.
2016-03-23 task T130399 0.0.14 Add x_analytics header inclusive filtering (consider pageview if header contains <code>pageview=1</code>), update ua-parser to an up-to-date version, correct a bug in search engine referer classification.
2016-04-11 task T131824, task T128612 0.0.15 Correct x_analytics header inclusive filtering (only apply pageview=1 tagging in mobile app pageview definition, and ensure correct status_code and mime_type before checking flag), update mobile app pageview accepted user-agent to WikipediaApp|Wikipedia/5.0. to cover for iOs app 5.0 release user-agent change. Mobile-app pageviews for IOS are incorrect from mid March since the launch of 5.0 version until about April 11th when user agent is updated.
2016-05-16 Task T135168 0.0.16 Correct pageview definition to flag mobile app pageviews when x_analytics header has pageview=1 set without checking for requests path (data will be backfilled in pageview table from 2015-05-02 21:00 onward). Add page title extraction for mobile apps restbase accessed pages.
2016-08-12 Task T142410 0.0.16 Correct cache_status header
2017-02-09 Task T156628, Task T155141, Task T157528 0.0.17 Update pageview definition to remove previews (POST with "action=submit" in query is now excluded from pageviews). Add DSXS (self-identified bot) to bot regex. Add namespace_id field.
2017-03-21 Task T142410 0.0.18 Update pageview definition to stop filtering out test[2].wikipedia.org from pageviews.
2017-06-13 Task T118557 0.0.18 Removed x_forwarded_for from webrequest logs. This field will be NULL from here on out in webrequest data in Hive. Use client_ip.
2017-08-23 Task T168874, Task T171760 0.0.19 Add project_family in normalized_host struct in preparation for deprecation of project_class (they have the same value). Addition of the tags column, containing an array of strings (tags) allowing for easier identification of rows. First usage of tags will be to create temporary smaller tables in order to reduce the full table scans needed by many jobs.
2017-11-03 Task T177199 Changed cache_status possible values to include cache-layer information (eg: hit -> hit-front). This change is coming from the raw data and not the refinery process, therefore no record-version bump is required.

Queries over the full table will sometimes fail with a java.io.FileNotFoundException: File does not exist error during execution, in case the purging of the oldest data (after 90 days) happens before the query accesses those partitions. This can be avoided by manually excluding the oldest available dates in the WHERE clause.

wmf_raw.webrequest

Likely you do not want to query the raw tables (your queries will be slow) but the processed ones (see above) that have a more friendly format when it comes to compression.

If you do query these tables you need to add the json serde to your path:

ADD JAR /usr/lib/hive-hcatalog/share/hcatalog/hive-hcatalog-core.jar ;

Load job (import)

Raw Webrequest logs are currently imported using Camus from Kafka. A Hive table with hourly partitions is mapped on top of this data. Webrequest logs are Snappy compressed SequenceFiles in JSON format. Using SequenceFiles makes it possible to use MapReduce jobs with compressed data.

In addition to the core data, two tables are created with detailed statistics about the hourly partition loaded.

  • wmf_raw.webrequest_sequence_stats -- Contains details for each varnish-kafka source of duplicates / missing data.
  • wmf_raw.webrequest_sequence_stats_hourly -- Contains hourly aggregated percent_missing and percent_loss for each webrequest source.

The statistics in those two tables are computed using a 'sequence' number, a counter generated by each varnish-kafka process incrementing its value for each line it outputs. This sequence number allows to track for duplicates and missing data using some arithmetics (max, min, distinct). For details look at the code for webrequest_sequence_stats and webrequest_sequence_stats_hourly).

Checking statistics

An usual request for checking high level statistics for load jobs is

SELECT
    year,
    month,
    day,
    hour,
    webrequest_source,
    percent_lost,
    percent_duplicate
FROM
    wmf_raw.webrequest_sequence_stats_hourly
WHERE
    -- Update the restrictions to your need.
    year = XXXX
    AND month = XX
    AND day = XX
    AND hour = XX
    AND webrequest_source IN (XXX)
ORDER BY
    year, month, day, hour, webrequest_source
LIMIT 1000;

API requests

If you want to look at API use, it makes more sense to API Action data, which is logged directly from MediaWiki when it responds to API requests. The benefits of that data include:

  • Includes internal API requests not routed through the Varnish servers
  • Data on API requests is not mixed in with data on regular web requests.
  • Contains detailed data on the content of POST API requests (they are logged in webrequests, but without the request bodies).

Other Hive tables that are based on Webrequest

The following Data Lake tables (accessible via Hive) are derived from the Webrequest table:

Notes

  1. It doesn't include some internal (within-cluster) API requests which are not routed through the Varnish servers.