Wikipedia talk:Wikipedia Signpost/2017-02-06/Technology report

A couple of clarifications, it was probably my fault not to express them clearly when I was asked. There are about 20 English Wikipedia core mediawiki replicas (the number is not fixed, newer servers are continuously being added/upgraded and others decomissioned). There are around 130 core db server in total for all projects serving wiki traffic, to maximize high availability and performance, and its topology can be seen at: https://dbtree.wikimedia.org/ Some auxiliary (non-core) servers are hidden for clarity. Should a meteorite hit the west cost of US, we could have all wiki projects running on the secondary datacenter in 30 minutes (?)- we are trying to get faster and better there. https://blog.wikimedia.org/2016/04/11/wikimedia-failover-test/ https://www.mediawiki.org/wiki/Wikimedia_Engineering/2016-17_Q3_Goals#Technical_Operations

Also, there is 2 (not 1) db servers delayed 24 hours, one per main datacenter, one just happens to be temporarily (for a few weeks) under maintenance and it is up but not "delayed" after hardware renewal (redundancy helps, not only a recovery method, but also for easier maintenance and less user impact).

In general, backups is something that one never stops working on- there is always room for faster backups, faster recovery, more backups, better verification, more redundancy, etc.

--jynus (talk) 14:55, 6 February 2017 (UTC)

PDF rendering
I'm really excited to learn that better PDF rendering is on the way -- this will be enormously helpful to many projects. I'm curious, will the rendering respect little customizations, e.g. whether one has chosen to show or hide the Table of Contents or collapsed text, or the sort order chosen in sortable tables? Also, is there any related progress on ODT or ePub output? -Pete Forsyth (talk) 21:41, 6 February 2017 (UTC)
 * It will render exactly the same as a printout of page would look like, if you would be an anonymous user (basically, it works just like "Print to PDF on any modern OS's print dialog). There is no progress on ODT or ePub output (as a matter of fact, it could be argued that we will be further from such a solution, by choosing for maintainable simplicity over unmaintainable complexity). —Th e DJ (talk • contribs) 12:55, 7 February 2017 (UTC)
 * , currently, "print to PDF" does respect whether or not the TOC is expanded. But if the browser engine doing the rendering is on the server side, will that still be the case? -Pete Forsyth (talk) 19:10, 7 February 2017 (UTC)
 * No, the rendering is serverside, so it has no idea about the context that your browser keeps. —Th e DJ (talk • contribs) 20:07, 7 February 2017 (UTC)
 * OK. As I suspected...and unfortunate, but difficult to change, I'd imagine. Thanks for the clarification! -Pete Forsyth (talk) 20:08, 7 February 2017 (UTC)
 * Glad to see the ability to have proper tables in PDFs is now likely. Quite a lot of my work on recent years has been tables and lists, and its been as real pain not to be able to render them. It means WP readers can't access them easily for study off web. I have had to place the texts in my word processor and format them there for my private use. Apwoolrich (talk) 11:16, 8 February 2017 (UTC)

I too am looking forward to see the glorious PDF function restored to its glory! Can't wait for books to be a thing again! Headbomb {talk / contribs / physics / books} 17:17, 13 February 2017 (UTC)