{"id":165,"date":"2019-11-29T18:37:42","date_gmt":"2019-11-29T18:37:42","guid":{"rendered":"https:\/\/blog.mozilla.org\/data\/?p=165"},"modified":"2020-05-11T15:19:45","modified_gmt":"2020-05-11T15:19:45","slug":"this-week-in-glean-differences","status":"publish","type":"post","link":"https:\/\/blog.mozilla.org\/data\/2019\/11\/29\/this-week-in-glean-differences\/","title":{"rendered":"This Week in Glean: Differences"},"content":{"rendered":"

(\u201cThis Week in Glean\u201d is a series of blog posts that the Glean Team at Mozilla is using to try to communicate better about our work. They could be release notes, documentation, hopes, dreams, or whatever: so long as it is inspired by Glean. You can find an index of all TWiG posts online<\/a>.)<\/em><\/p>\n

Currently my team is responsible for the Telemetry framework inside Firefox on Desktop and also the Glean SDK<\/a>, targeting our mobile products. We’re working on bringing the Glean experience to Firefox on Desktop, but in the meantime Telemetry<\/a> is what we have, need to support and sometimes implement new features on.<\/p>\n

One of these features is a new ping (or, better, a change in a ping), that we now want to support across all our products. I’m speaking of the deletion-request<\/code> ping<\/a> here. When a user opts out of Telemetry we take this as a signal to also delete associated data from our pipeline.<\/p>\n

Implementation in Firefox Desktop was merely renaming an existing ping<\/a> that is triggered when the user disables “Data Collection and Use” (about:preferences<\/code> -> Privacy & Security). It contains no additional data. Implementation in Glean was not much harder either. Glean already supports custom pings<\/a>: Pings that can be defined and send by the application using Glean. Glean’s internal pings follow the same pattern, they are just pre-defined. The biggest difference?<\/p>\n

It’s called deletion_request<\/code> ping instead.<\/p>\n

On ingestion data from a ping is decoded from its JSON form and put into tables on BigQuery (in our documentation you can find an overview of the data pipeline<\/a> if you are interested). BigQuery table names can only contain alphanumeric characters and underscores (see “Table naming”<\/a> in the BigQuery documentation). We avoid any translation in the pipeline by just enforcing this directly on ping names.<\/p>\n

Glean also enforces the payload schema of pings. Glean itself controls portion of the data, including a sequence number, date field and a bit of metadata about the application its running in (see the ping sections<\/a>). The rest of the payload consists of metrics<\/a> as defined by users of Glean. While implementing the new ping I stumbled upon another small detail of Glean: Pings won’t be sent out if they would not contain any metrics. And our new ping, by design, should not contain any metrics!<\/p>\n

We don’t want to change this for other pings, so I had to introduce a new flag now: sendIfEmpty<\/code> (PR #139<\/a>).<\/p>\n

That way we can allow the deletion_request<\/code> ping to be sent without any metrics in there, only containing the basic information.<\/p>\n

The implementation of the new ping is now done and currently waiting for data review (PR #526<\/a>). I hope to land this early next week.<\/p>\n

(( This is a syndicated copy of the original post<\/a>. ))<\/p>\n","protected":false},"excerpt":{"rendered":"

(\u201cThis Week in Glean\u201d is a series of blog posts that the Glean Team at Mozilla is using to try to communicate better about our work. They could be release … Read more<\/a><\/p>\n","protected":false},"author":1756,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[315988,448297],"tags":[],"coauthors":[],"_links":{"self":[{"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/posts\/165"}],"collection":[{"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/users\/1756"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/comments?post=165"}],"version-history":[{"count":0,"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/posts\/165\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/media?parent=165"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/categories?post=165"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/tags?post=165"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/blog.mozilla.org\/data\/wp-json\/wp\/v2\/coauthors?post=165"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}