Thanks Greg. There was nothing mentioned in today's Tech news, so I have just appended some information to enWS. At the WSes we load some big transcluded pages and I have set a little challenge for users to make some comparisons. Are you going to be running data comparisons? Is this something that user (anecdotal) semi-quantitative data is of value? If yes, to the last point, what sort of direct data comparison might be of value?
Regards, Billinghurst
On Fri, 12 Sep 2014 17:42:14 -0700, Greg Grossmeier greg@wikimedia.org wrote:
<quote name="billinghurst" date="2014-09-13" time="09:38:47 +1000"> > > * There will be a method to opt-in to using the new HHVM-powered > > backend > > for all WMF wikis. It'll be implemented via a BetaFeature to make
it
as easy as possible for people to participate. There should be no noticeable negative impact and hopefully only positive impacts.
Greg,
The last dot point. Is it there against Thursday 18th? Is it to mark it against another point? The HHVM component sits against next month on
the
deployment page, so the uncertainty.
To answer all of your questions I'll try to rephrase things in a different manner and add some more details. It might be a little too detailed at first, I'll try to tl;dr at the end:
HHVM is a virtual machine for PHP which improves the performance of the servers by... a lot. We're a little shy of sharing predictions of how improved the performance will be, but it'll be worth the effort.
Thus far HHVM has been deployed to the Beta Cluster, which is our testing environment based in WMF Labs. It has been running there for about a month so far.
Along side that we have a few servers in the production cluster that have been migrated to HHVM. These servers are only sent user traffic if and only if the user sets a cookie in their browser.
In addition to that there are safe-guards in place where if a request to an HHVM server fails, our Varnish layer will take note of that and resend requests to a normal (non-HHVM) server.
The confusion you have regarding HHVM being in the "Next Month" section is because this work is on-going. There were more bullets in that list initially and we will work through them as we get closer to the full rollout/completion.
What is happening next week is this: There will be a new Beta Feature available to all users that will allow them to opt-in to using the HHVM servers by default (the Beta Feature simply sets the cookie I mentioned above). That will happen on Thursday after the normal MediaWiki deploy.
If things go well, users who opt-in will have a better experience: pages should load faster and edits should save faster, for example.
If things don't go well, users who opt-in shouldn't see anything worse than normal (given that safe-guard I mentioned above in the Varnish layer).
tl;dr:
HHVM, an improved (faster) php server, is in the process of being tested at scale and rolled out. We are still at the beginning stages but we feel comfortable enough with the stability we've gained in the Beta Cluster to open it up to more users through a Beta Feature. This Beta Feature will be available for all users on Thursday afternoon (Pacific timezone). Users who opt-in should have a faster wiki experience and in the worst case will not see anything different than normal.
I hope that helps. If you have any more questions please don't hesitate to reply and cc wikitech-l, where the experts on the matter can answer more questions.
Best,
Greg