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Gmail, Google Maps and YouTube had outage issues

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Re: Gmail, Google Maps and YouTube had outage issues

#31

Post by wil421 »

eric_b wrote: post #25
wil421 wrote: post #16

Earlier quoted context omitted.

One reason is that by linking to external libraries your browser most likely has them cached. At least it was the case a few years ago when I was doing web dev.

I see this argument a lot but I don't think it's necessarily a good one. If a third party CDN goes down, your site is down. A few extra ms in initial download isn't so bad compared to having your site be completely inaccessible for reasons outside your control.

Self hosting will probably cause more downtime than if you are using a decent CDN. CDN is just one of many points of failure, I would expect there's a fine balancing act where you could achieve benefits of both.

Re: Gmail, Google Maps and YouTube had outage issues

#32

Post by omni »

eric_b wrote: post #25
wil421 wrote: post #16

Earlier quoted context omitted.

One reason is that by linking to external libraries your browser most likely has them cached. At least it was the case a few years ago when I was doing web dev.

I see this argument a lot but I don't think it's necessarily a good one. If a third party CDN goes down, your site is down. A few extra ms in initial download isn't so bad compared to having your site be completely inaccessible for reasons outside your control.

Why doesn't having the resources cached provide a buffer against short-term outages of the CDN?

Re: Gmail, Google Maps and YouTube had outage issues

#33

Post by matthberg »

eric_b wrote: post #25
wil421 wrote: post #16

Earlier quoted context omitted.

One reason is that by linking to external libraries your browser most likely has them cached. At least it was the case a few years ago when I was doing web dev.

I see this argument a lot but I don't think it's necessarily a good one. If a third party CDN goes down, your site is down. A few extra ms in initial download isn't so bad compared to having your site be completely inaccessible for reasons outside your control.

When a CDN goes down, that is the time to use local backups. The best policy I've seen is using 3rd party CDNs for scripts like jQuery, ie. common, unchanging resources, yet with subresource integrity checks [0] to make sure it's actually what you are asking for (in case the site somehow gets compromised or returns an error). On top of that to cover for failure, you have a fallback locally hosted copy which is loaded only if the CDN version fails.

[0] https://developer.mozilla.org/en-US/docs/Web/Security/Subres...

Re: Gmail, Google Maps and YouTube had outage issues

#34

Post by mholt »

jjlane wrote: post #3

Our site was using hosted libraries, google fonts, and google analytics. All of which seemed to be behind captchas, throwing CORS errors, and 503ing since this morning. Swapped out JQuery cdn for now.

Having the same problem here! Glad it wasn't just me...

Re: Gmail, Google Maps and YouTube had outage issues

#35

Post by dchest »

bcherny wrote: post #19
ocdtrekkie wrote: post #10

Earlier quoted context omitted.

Is there a good reason to use these things hosted by a third party source? Libraries are tiny, the fonts can be downloaded from Google Fonts and embedded locally, etc. Even the Google Analytics JS script I presume can be stored and run local. Shouldn't a goal be to mitigate the number of possible failures which can bring down your site by reducing the number of single points of failure?

2 reasons: 1. If you're still using HTTP 1.x, sharding assets across origins lets the browser load them in parallel (if set up correctly). You can generally load just 6 assets in parallel per origin, and sharding is a way to get around that limit. 2. A library like jQuery is so popular, and is so often served from googles CDN, that chances are a user already has it in their local cache from when they downloaded it on…

2. A library like jQuery is so popular, and is so often served from googles CDN, that chances are a user already has it in their local cache from when they downloaded it on some other site.

Which of these versions do you have cached?

3.2.1, 3.2.0, 3.1.1, 3.1.0, 3.0.0, 2.2.4, 2.2.3, 2.2.2, 2.2.1, 2.2.0, 2.1.4, 2.1.3, 2.1.1, 2.1.0, 2.0.3, 2.0.2, 2.0.1, 2.0.0, 1.12.4, 1.12.3, 1.12.2, 1.12.1, 1.12.0, 1.11.3, 1.11.2, 1.11.1, 1.11.0, 1.10.2, 1.10.1, 1.10.0, 1.9.1, 1.9.0, 1.8.3, 1.8.2, 1.8.1, 1.8.0, 1.7.2, 1.7.1, 1.7.0, 1.6.4, 1.6.3, 1.6.2, 1.6.1, 1.6.0, 1.5.2, 1.5.1, 1.5.0, 1.4.4, 1.4.3, 1.4.2, 1.4.1, 1.4.0, 1.3.2, 1.3.1, 1.3.0, 1.2.6, 1.2.3

Re: Gmail, Google Maps and YouTube had outage issues

#36

Post by jlgaddis »

eric_b wrote: post #25
wil421 wrote: post #16

Earlier quoted context omitted.

One reason is that by linking to external libraries your browser most likely has them cached. At least it was the case a few years ago when I was doing web dev.

I see this argument a lot but I don't think it's necessarily a good one. If a third party CDN goes down, your site is down. A few extra ms in initial download isn't so bad compared to having your site be completely inaccessible for reasons outside your control.

Then why are these sites down?

Re: Gmail, Google Maps and YouTube had outage issues

#37

Post by wil421 »

matthberg wrote: post #33
eric_b wrote: post #25

Earlier quoted context omitted.

I see this argument a lot but I don't think it's necessarily a good one. If a third party CDN goes down, your site is down. A few extra ms in initial download isn't so bad compared to having your site be completely inaccessible for reasons outside your control.

When a CDN goes down, that is the time to use local backups. The best policy I've seen is using 3rd party CDNs for scripts like jQuery, ie. common, unchanging resources, yet with subresource integrity checks [0] to make sure it's actually what you are asking for (in case the site somehow gets compromised or returns an error). On top of that to cover for failure, you have a fallback locally hosted copy which is loaded…

Would those resource checks been done at the client or sever? For example the sever pings the CDN at a set interval and if it's down the sites code is modified to included links to local copies.

Or would you do something in the browser to fetch the local one in case of failure?

Re: Gmail, Google Maps and YouTube had outage issues

#38

Post by castis »

dchest wrote: post #35
bcherny wrote: post #19

Earlier quoted context omitted.

2 reasons: 1. If you're still using HTTP 1.x, sharding assets across origins lets the browser load them in parallel (if set up correctly). You can generally load just 6 assets in parallel per origin, and sharding is a way to get around that limit. 2. A library like jQuery is so popular, and is so often served from googles CDN, that chances are a user already has it in their local cache from when they downloaded it on…

2. A library like jQuery is so popular, and is so often served from googles CDN, that chances are a user already has it in their local cache from when they downloaded it on some other site. Which of these versions do you have cached? 3.2.1, 3.2.0, 3.1.1, 3.1.0, 3.0.0, 2.2.4, 2.2.3, 2.2.2, 2.2.1, 2.2.0, 2.1.4, 2.1.3, 2.1.1, 2.1.0, 2.0.3, 2.0.2, 2.0.1, 2.0.0, 1.12.4, 1.12.3, 1.12.2, 1.12.1, 1.12.0, 1.11.3, 1.11.2, 1.11…

Asking an annoyed rhetorical question doesn't seem productive to the point you're trying to make here.

As an actual answer, it would be variable proportional to the size of the window between releases mentioned here: https://en.wikipedia.org/wiki/JQuery#Release_history

I'm sure a fair amount of people serve jQuery from a local storage. The usefulness that the user might already have it cached is a non-zero point, no matter how insignificant you may think it is.

Re: Gmail, Google Maps and YouTube had outage issues

#39

Post by nleach »

omni wrote: post #32
eric_b wrote: post #25

Earlier quoted context omitted.

I see this argument a lot but I don't think it's necessarily a good one. If a third party CDN goes down, your site is down. A few extra ms in initial download isn't so bad compared to having your site be completely inaccessible for reasons outside your control.

Why doesn't having the resources cached provide a buffer against short-term outages of the CDN?

The browser still has to make a request to the CDN to get back an HTTP 304. The goal is to avoid downloading a potentially large payload, not be resilient against connectivity issues.
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