Rust at CloudFlare

https://docs.google.com/presentation/d/1ERVTXZbYBMZf-9Zk3YsWw2oV14C5j0i1PsVgGywSsAI/mobilepresent?slide=id.g244c4c34_09

by steveklabnik • 8 years ago

271 55 8 years ago

docs.google.com

tormeh• 8 years ago

Can anyone offer some context? Redox is great, but why is it a pro for cloudflare?

jontro• 8 years ago

It's listed under the Why rust (for me) slide. I.e. it's the authors own reasons/pros.

weavie• 8 years ago

Does that mean it is actually being used in production, or is it just a potential? If so, I hadn't realised it had come on that far!

steven_pack7• 8 years ago

That was purely on the list of reasons why I personally got interested in Rust and I support redox on patreon. I love the idea of an OS built on Rust from the ground up as a way to eliminate a category of security bugs.

The second slide is about when Cloudflare chooses Rust as a language.

buro95• 8 years ago

I'm the Engineering Manager @ Cloudflare for the "Wireshark but at the Edge" thing. Happy to answer any questions, though I'll be clear... this isn't something you can play with yet and we're in early days with this feature.

The goal is "customers should be able to create filters that target traffic passing through our system and then do things" so this is definitely a thing we wish to give to customers rather than an internal toy.

wyldfire• 8 years ago

Do you have NICs/FPGAs that this code could target or would those filters run on a CPU?

buro95• 8 years ago

CPU presently.

The filter expressions are based on the Wireshark Display Filters https://www.wireshark.org/docs/wsug_html_chunked/ChWorkBuild... and we support everything except the slice operator.

Rust handles the parsing, validation, AST creation, etc. That AST can then be applied to a trait table similar to the Wireshark implementation but without the necessity of a pcap step.

I hope that the filter becomes an invariant form of filter against traffic and that once we've got the AST we can apply that filter to different places. Initially just to itself within a Rust matching engine at the edge, but if you have columns on a DB why not ask for a SQL expression derived from the filter expression and then filter a ClickHouse store using the same filter, and likewise as per your suggestion if we can take some of the expressions that aren't L7 why can't we have these run in the network card, etc.

Right now... just CPU as it is early days. But eventually we can look at all places we match traffic and consider that a contender for the same filter to be applied there.

Rapzid• 8 years ago

I wouldn't mind hearing some details on perf. I would imagine a lot of filtering can happen at the true edge via BPF, kernel mods, or otherwise zerocopy mechanisms.

Looks like Linux added in kernel tls termination; sounds like even layer 7 inspection could all happen in kernel space as well...

buro95• 8 years ago

Ah, for this I'll defer until we have more data.

At the moment we have a simple(ish) implementation running at the edge purely within Nginx and a project underway to see how it behaves, gather metrics. That environment gives us a good place in which to control testing, and we can easily compare it to other parts of our code where we already do more trivial request matching (our Page Rules feature).

It'll be a couple of months before we're satisfied we know enough to say whether we'll keep it simple or will seek to make it more specialised to our environment. We haven't yet determined how far we're going to go with this... could it replace our WAF? Is it cheap enough for the DDoS layer? If we do go down those paths then it's obvious that yes we'd move the filtering to other places.

jeffdavis• 8 years ago

If I understand correctly, this is basically a new project/initiative, so the results aren't in yet, right?

Do you have in mind some success criteria for the choice of rust that you can evaluate maybe in 6 months?

[I'm not looking for scientific rigor here, just a "this is what we expected from rust" and you can look later and see if those expectations matched reality.]

buro95• 8 years ago

Correct on the first part.

We chose Rust not just for the expected speed and safety but also because we needed to create a shared object that could provide the API (written in Go) with exactly the same parsing and matching engine as our edge (initially Nginx for web traffic written in C and Lua).

The key was to produce consistent behaviour in the way we work with filter expressions such that there is no difference in behaviour that can be leveraged by malicious users later. i.e. if a customer used a filter to create a security rule and that filter behaved even slightly differently later then that would be a security incident in the making and we would have failed our customer.

Rust stood out for being a safer language than C (we had that bug) that could produce a shared object we can use in our API (unlike Lua which does not make this easy), and didn't come with the garbage collection.

We already have some other small bits of Rust in part of our dev pipeline so were comfortable selecting it, but this is the first time we would be shipping Rust globally and running it at the edge.

Our main expectation and hope is performance.

The matching engine that applies the filters is on the hot path for handling requests, it's early in the request lifecycle and all traffic on a zone (customer domain) would need to be evaluated to see whether traffic applies to any existing filter. So the numbers we are looking to gather relate to the time it takes to execute expressions similar to what we have already, as well as more complex expressions, and what this does to CPU load - those two things will dictate how this new project affects the throughput.

The hope is that a more powerful matching engine that is fast and doesn't increase CPU load will allow us to remove code from our system whilst providing customers with fine grained control of all features. Today a lot of features implement their own matching on paths, headers, etc... and these are not always efficient and are implemented inconsistently.

Performance is therefore what we are focused on measuring and improving, and we hope that if the numbers are good Rust will provide us the opportunity to remove other code and increase throughput whilst not giving us fear that such a change has opened us up to other more fundamental risks.

squiguy72• 8 years ago

It's cool to see CloudFlare using Rust but I wish they went into a little more detail on the slides. I hope to see follow up blog posts or some of the code open sourced soon.

steven_pack7• 8 years ago

That's what happens when Product Managers present the things the engineering team is doing. :) The bigger projects are in London. I'm going to try get the engineers out to SF next time we host and go a bit deeper. The EM is on this thread answering questions also.

squiguy72• 8 years ago

Ok, great. Thanks for sharing the information as it is! :)

Already__Taken• 8 years ago

2 videos up on the rust channel from this and hopefully more in future - https://www.youtube.com/channel/UCaYhcUwRBNscFNUKTjgPFiA/vid...

brian_herman• 8 years ago

TrustDNS awesome for 1.1.1.1

bluejekyll• 8 years ago

We're putting the 0.9 release of the Resolver together now, hopefully for release in the next few days. Lot's of good things, including DNS-over-TLS with cloudflare and quad9 configs available.

cortesoft4• 8 years ago

Hmmm, they say only 10Tbps capacity, but they serve 10% of the internet's HTTP traffic? That doesn't seem right.

noselasd• 8 years ago

I read it as 120 datacenters, each with 10Tbps capacity

cortesoft4• 8 years ago

Yeah, that isn’t possible.

majke• 8 years ago

The "10%" is always going to be a metric of something. If you count bytes in the internet, to some approximation it's 100% netflix + youtube (with some error :P).

Here, the metric probably means "unique domain names" used on the internet.

steven_pack7• 8 years ago

The slide says 10% requests. http[s] requests that is, not packets.

lossolo2• 8 years ago

Only? 10 Tbps is HUGE capacity. Biggest IX (Internet Exchange) which is AMS-IX have 5 Tbps at peak. Whole internet traffic in 2016 was around 160 Tbps. So it seems right.

cortesoft4• 8 years ago

disclaimer: I work for a CDN, but am not representing them with this comment

Right, but this is talking about GLOBAL capacity, not at a single datacenter. The CDN I work for has over 49tbps, and we wouldn't claim to be doing 10% of all HTTP traffic:

https://images.verizondigitalmedia.com/2015/12/VDMS_NetworkM...

Plus, capacity is always going to be greater than actual throughput, both for reliability reasons and traffic patterns (i.e. you need enough capacity for your peak traffic in a datacenter, not the average)

I really doubt the 10% claim.

steven_pack7• 8 years ago

Here are the videos and slides... (from the May 2018 Bay Area Rust Meetup, which was hosted at Cloudflare)

Rust at Cloudflare Video: https://watch.cloudflarestream.com/4d5d6da3c6217c24f4e44564e... Slides: https://docs.google.com/presentation/d/1ERVTXZbYBMZf-9Zk3YsW...

TrustDNS Video: https://watch.cloudflarestream.com/e14e0d2335ffb94ae505289f5... Slides: https://drive.google.com/drive/folders/1gQn9Uuj34TxS4cfUoW1N...

Rust Perf with lolbench Video: https://watch.cloudflarestream.com/5774ee39218ed516521adb74c... Slides: https://docs.google.com/presentation/d/1BEI7zXhEiCwEd93-UUpW...

edit: context about the event edit2: formatting

manigandham2• 8 years ago

Thanks for the info. 1 thing: I know you guys have your own Stream video service but Youtube is still much nicer for viewing...

dikaiosune• 8 years ago

The official (I think?) youtube channel has them: https://www.youtube.com/channel/UCaYhcUwRBNscFNUKTjgPFiA.

steven_pack7• 8 years ago

My pleasure! Hey, what do you like more about YouTube for watching the videos?

kornish• 8 years ago

I like the quote from Slide 10:

Why Rust (for CloudFlare)
...
- Safe (we had a bug once...)
...

Funny because according to Algolia, the bug in question is the 7th-most-upvoted HN post of all time, clocking in at about 1k comments.

Great to see Rust gaining industry adoption.

edit: to clarify, I like that Cloudflare can look back at a bug in their C code, chuckle about it, and then start to move on to something safer. This is the bug in question: https://news.ycombinator.com/item?id=13718752

hellofunk2• 8 years ago

Could you provide a link to it?

lobster_johnson2• 8 years ago

I suspect it's this bug: https://blog.cloudflare.com/incident-report-on-memory-leak-c...

HN: https://news.ycombinator.com/item?id=13718752

enitihas• 8 years ago

I think this one https://news.ycombinator.com/item?id=13718752

jiveturkey• 8 years ago

just me, or anyone else find it odd that this is a google docs deck? don't see those published much (usu. pdf and of course ppt).

anyway, another example of soft recruiting done right by cloudflare!

qiqing• 8 years ago

Also, Cloudflare is hiring.

theweb1• 8 years ago

http traffic from cloudflare is cutting edges.

Rust at CloudFlare

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