Electrolysis

Overview

Electrolysis functionality hosts, renders, or executes web related content in background child processes which communicate with the "parent" Firefox browser via various ipdl protocols. The two major advantages of this model are security and performance. Security improvements are accomplished through security sandboxing, performance improvements are born out of the fact that multiple processes better leverage available client computing power.

Electrolysis child processes are currently in use for the following tasks within Firefox:

Legacy NPAPI plugin hosting
Media playback
Web content ('content processes')

In the future Electrolysis child processes may be used to handle other browser tasks including graphical composition, and addon hosting for addons that leverage the new WebExtensions apis.

In Mozilla documentation "Electrolysis" is often shorted as "e10s".

Enabling and Disabling Electrolysis on Nightly/Aurora

If you're on Nightly or Aurora, e10s is already enabled by default! A user facing checkbox is available for controlling Electrolysis functionality. Open Preferences and check the "Enable multi-process" checkbox and then restart your browser:

For release builds (Beta, Release, ESR) enabling Electrolysis is controlled through an internal preference.

Enabling and Disabling Electrolysis on Beta

If you're on beta, you might be using / have already used e10s for some periods of time as we're running experiments to evaluate its stabililty.

However, if you want to permanently opt-in, you can do so with a simple pref change. Just go to about:config and toggle browser.tabs.remote.autostart to true. On your next restart, e10s should be active. To verify that it is active, go to about:support and look for a number higher than 0 in "Multiprocess Windows".

Enabling and Disabling Electrolysis on Release

Multiprocess is not yet available on the release channel. Stay tuned! If you really want to test it we suggest you to use Beta and help us test it!

Force-enabling e10s

If you've tried to enable e10s, but you see information in about:support saying that it is disabled by some reason (e.g., Add-ons), you can create and set to true a pref called browser.tabs.remote.force-enable. That is not encouraged though, so use it at your own risk, and only if you know what you're doing.

What to Expect

Generally the browser should be stable and usable, without major issues or crashes. Profiles that have lots of older addons will likely experience slowness or other issues. If you run into any trouble, try disabling incompatible add-ons.

Schedule and Status

A single content process model is currently being tested on Nightly, Aurora and Beta channels. See the schedule below for planned rollout to release. A multiple content process model will roll out in a follow up release. View the Multiple Content Process wiki page for more information.

Schedule

The following schedule covers rollout of the single content process feature to release builds.

Date	Trunk	Aurora	Beta	Release
2015-04-30	40 default (working on m5)	39 off	38 off	37 off
2015-05-11	41 default (working on m6)	40 prompt	39 off	38 off
2015-06-29	42 default (working on m7/m8)	41 prompt	40 off	39 off
2015-08-10	43 default (working on m8)	42 default	41 off	40 off
2015-09-21	44 default	43 default	42 off	41 off
2015-11-02	45 default	44 default	43 off	42 off
2015-12-14	46 default	45 default	44 A/B [1]	43 off
2016-01-25	47 default	46 default	45 A/B [1]	44 off
2016-03-07	48 default	47 default	46 A/B [1]	45 off
2016-04-25	49 default	48 default	47 50% [1][2]	46 off
2016-06-06	50 default	49 default	48 [1][2]	47 off
2016-08-01	51 default	50 default	49 [1][2]	48 [3]
2016-09-12	52 default	51 default	50 [1][2][4?]	49 [5]

[1] qualifying users: users that do not use addons and have not activated accessibility support over 30 days.
[2] full run across the entire beta period
[3] 1% of qualifying users with ramp up during the cycle
[4] white listed addons testing on beta
[5] 100% of qualifying users

Staged Roll-Out Plan

Weekly Status Reports

Experiments

There's a dedicated page for the experiments: E10s Experiments

Contributing

The simplest way to help out is to test a release that has e10s enabled, and file bug when you find them. Please try to find duplicates prior to filing.

The project roadmap overview provides current bug lists slated for development based on a set of 2015 milestones.
The current incoming e10s weekly triage bug list. Check this for "fresh" issues recently filed.
Here's a bugzilla template link for filing a new e10s bug: http://is.gd/aTza8A
When filing a new bug, please add the tracking-e10s:? flag or place 'e10s' in the bug title so that it shows up in the team's weekly triage bug list.

For developers interested in helping out, MDN has a good introduction to e10s, useful for both Firefox and add-on developers.

Security Sandboxing

See the Security Sandbox wiki page for more information and status.

Accessibility Support

See the e10s Accessibility wiki page for support implementation detail.

Add-ons Compatibility

Add-on authors should refer to the MDN Firefox Add-on Migration Guide for porting existing add-ons to e10s. For general design information see the Multiprocess Firefox MDN documentation.

Add-on testing compatibility is currently available at http://arewee10syet.com.

Past Milestones

2014-09-11 - bug 1064885 - Enable opt-in option for Nightly
2014-11-13 - bug 1093691 - Enabled for Nightly builds
2015-05-08 - bug 1161260 - Enable opt-in option for Aurora
2015-07-28 - bug 1182097 - Disabled on Aurora for about 1 week due to a bug in a11y prompting
2015-07-31 - bug 1188605 - Enabled for Aurora builds
2015-12-15 - bug 1229104 - Beta testing

Communication

Weekly Team Meeting	Weekly Team Meeting Thursday at 9:00am PT Vidyo: "e10s" Invitation: Contact blassey, jimm, or larissa to get added to the meeting invite list. Meeting Notes
Weekly Addons Strategy Meeting	Vidyo: "e10s" Invitation: Contact billm to get added to the meeting invite list. Meeting Notes Etherpad
IRC	Server: irc.mozilla.org Channel: #e10s
Newsgroup/Mailing List	https://lists.mozilla.org/listinfo/dev-tech-electrolysis

People

Engineering Management	Brad Lassey
Product Management	Jeff Griffiths
Project Management	Erin Lancaster - e10s Go to Market Shell Escalante - Add-Ons
QA	Tracy Walker (e10s Quality Assurance Lead)
Development Team	Mike Conley Felipe Gomes Blake Kaplan Gabor Krizsanits William McCloskey Jim Mathies Tom Schuster Dave Townsend George Wright