Data Platform/Data Lake/Traffic/Webrequest

The webrequest data stream contains all the hits to Wikimedia's servers, including requests for page HTML, images, CSS, and Javascript; API requests; and analytics event submissions.It doesn't include some internal (within-cluster) API requests which are not routed through the Varnish servers.
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 query the much smaller pageview_hourly and projectview_hourly tables. These are derived from webrequest by filtering to keep only pageviews and aggregating over a predefined set of dimensions.
For privacy reasons, this data is generally purged after 90 days.
== Pipeline ==
=== Varnish ===
The stream originates from the Varnish caching servers, which emit log data in their cache log format. A Varnishkafka instance (Puppet code) pipes the Varnish log data into Kafka, in the webrequest_text and webrequest_upload topics. 
VarnishKafka includes some logging mechanisms, and is tested with integration tests.
Instrumentation and checks:
* The VarnishKafka Kafka producer is sending metrics to Prometheus
* There is a metrics dashboard in Grafana
* Duplication and completeness checks of the Kafka export is processed during the Refine step.
Alerts:
* VarnishkafkaNoMessages: We fire a warning if the rate of Kafka messages is less than 20% (10%) of the rate of varnish requests over a 5 minutes period.
* VarnishKafkaDeliveryErrors: When we average more than 1 (5) error(s) per second per caching method, instance, and data center.Known caveats:
* Currently, there is no sanity check between Varnish logs and Kafka messages.
* Currently, there is no check that all Varnish instances bundle a running VarnishKafka beside them.
=== Kafka ===
2 topics hold the webrequest data: webrequest_text and webrequest_upload.
The cluster is maintained by the SRE team with monitoring and alerting.
Only 1 cluster is used to hold the topics: Jumbo in eqiad. And the topics are replicated with Kafka mirror in codfw.
=== Gobblin ===
Gobblin then loads the data from Kafka into HDFS, where it is stored as Snappy-compressed SequenceFiles in JSON format in hdfs://analytics-hadoop/wmf/data/raw/webrequest. A Hive table with hourly partitions is mapped on top of these data files. This is wmf_raw.webrequest.
We can monitor the process on Grafana (Data customly sent to Prometheus) and Yarn. And alerts fires when the scrapping process takes too long or when there is a mismatch in the counts between input and outputs
The job is triggered on an-launcher1002 with systemd.
About Gobblin metrics: Analytics/Cluster/Gobblin#Gobblin metric details
=== Refine ===
An Airflow job (code) then checks for missing or duplicated data and creates a "refined" copy which has additional fields and is stored as a Parquet file. Parquet is a column-based data storage format, which is much more efficient to query than the "raw" JSON data (see Data Format Experiments#Results for more info). This refined copy is wmf.webrequest.
The jobs are currently monitored from Airflow, YARN and through the dataloss tables.
The DataLoss check:
* first computes stats about webrequest into `wmf.webrequest_sequence_stats(_hourly)` Hive tables,
* then, sends email in case some requests are lost between the producer and HDFS,
* if request duplications are detected,
* or if the the `dt` param is missing.
== Pipeline administration ==
When the webrequest job fails, it is important to find the problem and rerun it as quickly as possible, because it is upstream from many other pipelines and it uses more resources than other jobs. Following are common problems and rerun procedures:
=== Corrupted data ===
It's when a small number of rows of a webrequest hour have an incorrect format and break the refinement process (for instance the x_analytics header, which is parsed into a map). You need to build requests to the data manually to find the rows which break the process. The identifying fields for a single row over an hour are the pair (hostname, sequence). If the number of rows is small (less than 100), you can then rerun the webrequest failed hour in Airflow with a specific airflow variable set: in the refine_webrequest_hourly_text_config variable (for the text partition), add a json value as follow: "excluded_row_ids":"'hostname1', sequence1, 'hostname2', sequence2..." . This will remove the faulty rows from the refined process. Important: Don't forget to remove the excluded_row_ids part of the variable once the run has succeeded, to not remove rows from later hours.
== wmf.webrequest ==
If you want to query the webrequest stream, you almost always want to use the "refined" version available in wmf.webrequest, which been enriched with extra fields and stored in a format that is much faster to query. (NOTE: descriptions below are a little brief on purpose, for precise definitions you can look at the refine step, which is a simple Hive query invoking UDFs, and follow that through by searching refinery-source)
=== Current Schema ===
Note: please see the usage notes section below with important information about this table's partitions and fields. 
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 in seconds (a sample value is .000243). The time it took from when the req was first received by varnish until it started sending response bytes back to the client.
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 – including the leading "?" if set
content_type 	string 	Content-Type header of response
referer 	string 	Referer header of the request. "Unknown" value indicates that url in referrer was not parseable or defective, "-" indicates no referrer was received.
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> 	The X-Analytics header broken up into key-value pairs
ts 	timestamp 	Unix timestamp in milliseconds extracted from dt
access_method 	string 	Client type used to access the site (mobile app, mobile web, or desktop). Mobile app requests are identified by the user agent including WikipediaApp or Wikipedia/5.0. Mobile web requests are identified by the hostname containing a subdomain of m, zero, wap, or mobile. Any other request is classified as desktop. This is implemented in the getAccessMethod function in refinery-source.
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 	The type of site found in the referer header: internal, external (search engine), external, none, 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 (e.g. en.wikipedia), language_variant, and page_title (e.g. Karan_Arjun or Special:Search). Populated only for pageviews (is_pageview = TRUE). page_title is the page_title requested, not the page_title shown to the user after redirects, which is different than the logic for page_id.
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.
isp_data 	map<string, string> 	Internet Service Provider data in a map with keys isp, organization, autonomous_system_organization and autonomous_system_number. Ex: {"organization":"blah-some","autonomous_system_organization":"some","isp":"Some","autonomous_system_number":"some number"}
accept 	string 	Accept header of request
tls 	string 	TLS information of request
tls_map 	string 	Map view of TLS information (keys are vers, keyx, auth and ciph)
ch_ua 	string 	Value of the Sec-CH-UA request header
ch_ua_mobile 	string 	Value of the Sec-CH-UA-Mobile request header
ch_ua_platform 	string 	Value of the Sec-CH-UA-Platform request header
webrequest_source	string 	Which Varnish cluster handled the request. Current values are text and upload (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)
referer_data 	struct<referer_class:string,referer_name:string>	Struct containing referer_class (indicates if a referer is internal, external, external(media sites), external(search engine) or unknown.) and referer name (name of referer when referer class is external(search engine) or external(media sites))
=== Usage notes ===
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.
The spider/user classification recorded in the agent_type field is based on the user agent, evaluated against some regexes (the standard spider detection provided by ua-parser augmented by a custom bot regex, see code for detail, or the Automated traffic page).
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.
=== Sample queries ===
====Distinct IPs====
SELECT
 COUNT(DISTINCT ip) AS hits
FROM
 webrequest
WHERE
 year = 2014
 AND month = 5
 AND day = 5
 AND hour = 13
 AND uri_host = "en.wikipedia.org"
 AND http_status = 200;
====Top raw referrals for an article ====
SELECT
 referer,
 COUNT(DISTINCT ip) AS hits
FROM
 webrequest
WHERE
 year = 2014
 AND month = 5
 AND day = 5
 AND hour = 13
 AND uri_path = "/wiki/London"
 AND uri_host = "en.wikipedia.org"
 AND http_status = 200
GROUP BY referer
ORDER BY hits DESC
LIMIT 50;
====Top internal referrals for an article====
SELECT
 SUBSTR(referer,30) AS source,
 COUNT(DISTINCT ip) AS hits
FROM
 webrequest
WHERE
 year = 2014
 AND month = 5
 AND day = 5
 AND hour = 13
 AND uri_path = "/wiki/London"
 AND uri_host = "en.wikipedia.org"
 AND referer LIKE "http://en.wikipedia.org/wiki/%"
 AND http_status = 200
GROUP BY
 SUBSTR(referer,30)
ORDER BY hits DESC
LIMIT 50;
====Top outbound clicks from an article====
SELECT
 SUBSTR(uri_path,7) AS target,
 COUNT(DISTINCT ip) AS hits
FROM
 webrequest
WHERE
 year = 2014
 AND month = 5
 AND day = 5
 AND hour = 13
 AND uri_host = "en.wikipedia.org"
 AND referer LIKE "http://en.wikipedia.org/wiki/London%"
AND 
 http_status = 200
GROUP BY SUBSTR(uri_path,7)
ORDER BY hits
DESC LIMIT 50; 
=== Changes and known problems since 2015-03-04 ===
:See also m:Research:Page view#Change log for changes to the page view definition itself, as well as Analytics/Data_Lake/Traffic/Pageview_hourly#Changes and known problems since 2015-06-16
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 	 	, 	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 	 	, , 	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 	 	, 	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.
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 	 	, , 	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 	 	, , 	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	 	 	 	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. 
 http://debugging.wmflabs.org/#refinery-graphs-tab. See also: Incident_documentation/20150803-Kafka,Incident_documentation/20150810-Kafka
2015-08-27 	 	, 	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 	 	, , 	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 	 	 	0.0.10 	Improve spider tagging adding user agent being .*http.* flagged as spider.
2015-12-01 	 	 	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 	 	 	0.0.12 	Referer classification has an updated version providing external search engine details (when any).
2016-03-09 	 	 	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 	 	 	0.0.14 	Add x_analytics header inclusive filtering (consider pageview if header contains pageview=1), update ua-parser to an up-to-date version, correct a bug in search engine referer classification.
2016-04-11 	 	, 	0.0.15 	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 	 	 	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 	 	 	0.0.16 	Correct cache_status header
2017-02-09 	 	, , 	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 	 	 	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.
2018-02-15 	 	 	0.0.20 	Add ISP data from MaxMind GeoIP2 ISP database to webrequest.
2018-04-10 	 	Task T191940 	 	For about 54min (from 22:46 - 23:40) on April 10, a significant portion of global traffic was not reaching our sites (incident documentation). The validity of the webrequest data itself appears to not have been affected.
2018-04 	 	 	 	From February 6 to April 16, 2018, the geolocation data for traffic from Opera browsers on mobile web was incorrect (wrongly labeled them as coming from the US, "Unknown" and some other countries rather than their true origin).
2018-05-02 	 	 	 	Add Ecosia and Startpage to list of search engines.
2018-05-21 	 	Task T193578 	 	Updated UA parsing source regexes. Mainly Windows NT (Windows 2000 to the present) requests now appear in the same OS family, as "Windows". Improves identification of page previews from browsers and devices, and correctly identifies devices previously marked as "Generic Android". Many requests that were marked wrongly as IE7 before are now (mostly) correctly identified as IE11.
2018-06-21 	 	 	 	Wikipedia Android app starts sending referer data (production release: 2018-06-27)
2018-07-26 	 	 	 	Update pageview definition to include foundation.wikimedia.org host
2018 -09-09 	onwards 	task T211077 	 	Referrer class change for Chrome Mobile
2018-10-09 	 	Task T170606 	 	Add accept header
2018-11-05 	 	Task T208752 	 	Issues with data coming from upload that might result in 'fake' traffic for some webp files
2019-01-07 	 	Task T212862, Task T153821	 	Updated IPs for Labs. Wikitech added to PageviewDefinition.
2019-04-01 	 	Task: T219842 	 	Kafka jumbo failover produces some data loss for hour 22 UTC.
2019-06-04 	 	 	 	From 2019-04-25 until 2019-06-04, pages with "+" in the title were omitted from pageviews.
2019-06-05 	 	 	 	From now on, user agent strings longer than 400 chars are not parsed.
2019-06-28 	 	 	 	doc.wikimedia.org host is not flagged as pageview anymore
2019-09-18 	 	 	0.0.22 	Update user-agent parser to up-to-date version. Main differences are os_family bug fixes (Windows 98 is now Windows for instance), os_major bug fixes (8.1 is now 8), Google Search App on iOS is not falsely counted at Safari anymore, and various device_family improvement.
2019-11-07 	 	 	 	Added tls and tls_map fields
2020-01-13 	 	 	 	Added several common search engines to the list of hard-coded search engine referers. Added a predictive referer classifier to classify non-hard-coded search engines. Introduced support for Android app referers.
2020-07-01 	 	 	0.0.23 	Update pageview definition for new android mobile content consumption.
2020-10-20 	 	 	0.0.24 	Remove latitude, longitude, and postal code from geocode_data map. These fields were inaccurate since they are based on IP address only and were unused.
2020-11-16 	 	 	 	Grow the number of buckets by which the table is bucketed from 64 to 256. Also apply a change supposedly applied in February 2017: make page_id a Bigint instead of an Integer.
2022-01-26 	 	 	 	Add low entropy Sec-CH-UA request headers: ch_ua, ch_ua_mobile, ch_ua_platform.
2022-01-26 	 	 	 	Data loss has been incurred from June 4th 2021 to January 26th 2022 due to a varnishkafka install problem on some of the caching hosts.
Summary of the data loss analysis:
* Between 2021-06-04 and 2021-11-03 we have lost on average 2.80% of webrequest-text, statv and eventlogging data (pageview impact, eqiad datacenter only)
* Between 2021-11-04 and 2022-01-27 we have lost on average 4.34% of webrequest-text, statv and eventlogging data (pageview impact, eqiad + ulsfo datacenters only)
* Between 2021-10-13 and 2021-11-03 we have lost on average 1.01% of webrequest-upload data (mediarequest impact, ulsfo datacenter only)
* Between 2021-11-04 and 2022-01-27 we have lost on average 2.19% of webrequest-upload data (mediarequest impact, ulsfo datacenter only)
2022-09-06 	 	 	0.0.25 	Add Brave, Petal, VK to list of search engines and expand predicted other to include suche domains (German).
2023-01-09 	 	task T326658 	 	Data loss has been incurred on January 8th 2023 between the 8th to14th hours due to issues encountered by Eqsin datacenter on 2023/01/08. 
Below is an analysis of the data loss:
At 2023-1-8-8 hour we lost an average of 8119100 records (2.8391253%) of valid webrequest text data.
At 2023-1-8-9 hour, we lost an average of 8313842 records (2.663%) of valid webrequest text data.
At 2023-1-8-10 hour, we lost an average of 8336440 requests (2.55%) of valid webrequest text data.
At 2023-1-8-11 hour, we lost an average of 10172609 requests (2.916%) of valid webrequest text data.
At 2023-1-8-12 hour, we lost an average of 11262617 requests (3.09%) of valid webrequest text data.
2023-1-8-13 hour, we lost an average of 11974996 requests (3.081%) of valid webrequest text data.
2023-1-8-14 hour, we lost an average of 10958911 requests (2.717%) of valid webrequest text data.
In summary, on 2023/01/8 between the 8th and 14th hours, we lost an average of 2.83% of webrequest-text data (from eqsin datacenter only).
2023-02-16 	 	task T327074 	0.0.26 	Add referer_data field to the schema
TBD (20230306) 	 	task T327073 	0.0.27 	Generation of the partition from Airflow+Spark (in place of Oozie+Hive)
== wmf_raw.webrequest ==
In almost all cases, you should not query this "unrefined" data, because the "refined" data in wmf.webrequest is richer and much faster to query.
If you do need query this raw data in Hive, you will first need to add the json "serde" (serializer-deserializer) to your path: ADD JAR /usr/lib/hive-hcatalog/share/hcatalog/hive-hcatalog-core.jar 
You can do this in Spark by invoking the Spark command line tool as follows: /usr/bin/spark2-shell --jars /usr/lib/hive-hcatalog/share/hcatalog/hive-hcatalog-core.jar.
== Data statistics ==
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 varnishkafka 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, see the code for webrequest_sequence_stats and webrequest_sequence_stats_hourly.
=== Querying the statistics ===
A typical query of these statistics is:
SELECT
 year,
 month,
 day,
 hour,
 webrequest_source,
 percent_lost,
 percent_duplicate
FROM wmf_raw.webrequest_sequence_stats_hourly
WHERE
 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;
For an example of querying to diagnose a data loss issue, see T211000.
== API requests ==
If you want to look at API use, it makes more sense to use the Mediawiki API request data stream 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).
== RAW IP usage for IP Data ==
Analytics/Data Lake/Traffic/Webrequest/RawIPUsage
== Derived streams ==
The following data streams (available as Data Lake tables) are derived from webrequest:
* Pageview hourly
* Pageview actor
* Projectview hourly
* Mediacounts
* Unique devices
*Browser general
*Mediawiki API request
*Mobile apps session metrics (deprecated - T329310)
*Mobile apps uniques (deprecated - T329310)
*Interlanguage navigation
See also Analytics/Data Lake/Traffic#Datasets.
== See also ==
* Research into referrer counts: 
== Notes ==
Category:Data stream
Category:Traffic data
Category:Data platform