Wikimedia Technology/Annual Plans/FY2019/TEC4: PHP7 Migration/Goals

Program Goals and Status for FY18/19

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  • Goal Owners: Mark Bergsma and Kate Chapman
  • Program Goals for FY18/19: At the conclusion of this program, Zend PHP7 will be the only PHP runtime supported or used in the Wikimedia Foundation production environment.
  • Annual Plan: PHP7 Migration

Outcome 1 / Output 1.2

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Zend PHP7 is the only PHP runtime in use in the WMF environment

All wikis, including wikitech/office/etc, are being run under the Zend PHP7 runtime

Dependencies on: Traffic & Performance teams; Primary team: Service Operations

Goal(s)

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Allow MediaWiki requests to be served by PHP7 alongside HHVM

  • Install and configure php-fpm alongside HHVM on the application servers   In progress
  • Refactor Apache configuration to allow selection of PHP engine based on HTTP request   In progress
  • Stretch: Evaluate performance of PHP 7.0, 7.2 versus HHVM, and pick one.  N Stalled
  • Stretch: Refactor the puppet module "mediawiki" classes to role/profile structure   To do

Status

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  Note: July 2018

  To do

  Note: August 14, 2018

  In progress

  Note: September 11, 2018

  In progress This goal is ongoing but slightly behind schedule due to high priority work on the data center switchover, as well as unexpected absence & vacations. It is though expected to complete shortly after EOQ. The stretch goal of evaluating PHP7 performance is currently stalled, as MediaWiki currently still does not pass all tests on PHP7.2


Outcome 1 / Output 1.2

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Zend PHP7 is the only PHP runtime in use in the WMF environment

All wikis, including wikitech/office/etc, are being run under the Zend PHP7 runtime

Primary teams: Performance & Core Platform

Goal(s)

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  • A sampling profiler that works under PHP7 has been identified and is prepared for use in the WMF production environment. If no appropriate profiler can be identified, then a statement of work for contractor effort to build one is prepared.

Status

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  Note: July 30, 2018

  To do

  Note: August 2018

  In progress Somewhat at risk due to Core Platform's other work load, might be at risk for completion this quarter.

  Note: September 11, 2018

  In progress Somewhat at risk due to Core Platform's other work load, might be at risk for completion this quarter.

Outcome 1 / Output 1.2

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Zend PHP7 is the only PHP runtime in use in the WMF environment

All wikis, including wikitech/office/etc, are being run under the Zend PHP7 runtime

Dependencies on: Traffic, Performance, Core Platform teams; Primary team: Service Operations

Goal(s)

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Ability to serve a % of production traffic from PHP7

  • Separate Traffic layer caches for PHP7/HHVM   Partially done
  • Allow directing users to PHP7 based on a cookie/header/beta feature   Done
  • Evaluate scalability and performance of php7 compared to HHVM (Performance/SRE)   Done
  • Package and install PHP 7.2 in production in place of PHP 7.0   Done
  • Assist in the production deployment of a custom written PHP profiler (Performance)   Done

Status

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  Note: October 18, 2018

MW isn't running under PHP7 yet, so some of the goals are not yet   In progress, others should be done by end of October.

  Note: November 14, 2018

PHP 7.2 has been packaged and installed in Beta, production deployment is imminent and is now   Partially done

  Note: December 12, 2018

Profiler is tested, final code reviews for wider deploy are   In progress and everything else is   Done for this goal.

  Note: January 9, 2019

Discussed that assisting in the production deployment has now been   Done by the Performance team

Outcome 1 / Output 1.2

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Zend PHP7 is the only PHP runtime in use in the WMF environment

All wikis, including wikitech/office/etc, are being run under the Zend PHP7 runtime

Primary teams: Performance & Core Platform

Goal(s)

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  • A sampling profiler that works under PHP7 has been identified and is prepared for use in the WMF production environment. If no appropriate profiler can be identified, then a statement of work for contractor effort to build one is prepared.   Done
  • Identify and address code issues and opportunities under PHP 7.2   Done

Status

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  Note: July 30, 2018

  To do

  Note: August 2018

  In progress Somewhat at risk due to Core Platform's other work load, might be at risk for completion this quarter.

  Note: September 11, 2018

  In progress Somewhat at risk due to Core Platform's other work load, might be at risk for completion this quarter.

  Note: November 14, 2018

  In progress See https://phabricator.wikimedia.org/T205059

  Note: December 12, 2018

Sampling profiler is   Done, deploy is tracked under output 1.1.

Outcome 1 / Output 1.2

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Zend PHP7 is the only PHP runtime in use in the WMF environment

All wikis, including wikitech/office/etc, are being run under the Zend PHP7 runtime

Dependencies on: Performance, Core Platform, Release Engineering team; Primary team: Service Operations

Goal(s)

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Ramp-up serving traffic to PHP 7

  • Set up a beta feature to allow users to test PHP 7   Done
  • Setup of the sampling/profiling pipeline (Performance, with assistance from SRE)   In progress
  • Set up curl connection pooling mechanism   Done
  • Optimize deployments for PHP7   Done
    • Allow scap to invalidate the opcode cache   Done
    • [stretch] Allow fetching the database configuration from etcd instead of files in order to reduce the cache resets
  • Set up A/B testing mechanism for PHP7, ramp up traffic to 20% of users   In progress

Status

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  To do January 2019

Discussed...

  Note: February 13, 2019

  • PHP7 has been deployed as a Beta feature, and newly found bugs due to beta testing are being investigated. A curl connection pooling mechanism has been implemented. Scap invalidation of the opcode cache is nearly done. On track and   In progress

  Note: March 27, 2019

  • Setup of the sampling/profiling pipeline is still   In progress and will go into Q4.
  • Stretch goal of allowing fetching the database configuration from etcd is still   In progress and will continue into Q4
  • A/B testing mechanism for PHP7 is at about 1% and will continue to be   In progress in Q4

Outcome 1 / Output 1.2 (SRE)

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Zend PHP7 is the only PHP runtime in use in the WMF environment

All wikis, including wikitech/office/etc, are being run under the Zend PHP7 runtime

Dependancies on: ___________

Goal(s)

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  • Complete the transition to PHP 7 in production
    • Move all application server & API traffic to PHP 7
    • Move maintenance scripts to PHP 7 (stretch)
    • Move jobrunners to PHP 7 (stretch)
    • Remove HHVM from production (stretch)

Status

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  Note: May 8, 2019

  • Transition to PHP is at 5% anon, moving traffic over now, but it's taking time to do this smoothly, so   In progress
  • Stretch goals might not be able to be done this quarter.

  Note: June 13, 2019

  • A portion of this is  N Blocked on emergent bugs /issues (at 20% right now) and will continue into next week. MOve maint scripts and job runners are   In progress but the removing of HHVM won't be done until next FY.


Outcome 1 / Output 1.2 (Performance)

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Zend PHP7 is the only PHP runtime in use in the WMF environment

All wikis, including wikitech/office/etc, are being run under the Zend PHP7 runtime

Dependencies on: SRE

Goal(s)

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  • Support with rollout of PHP7


Status

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  Note: May 8, 2019

  • This is   In progress and going well.

  Note: June 27, 2019

  • This is   In progress and will finish up in the next quarter.