Ruby Video
Talks
Closing Keynote
Aaron Patterson
@tenderlove
#ruby-on-rails
#activerecord
#concurrency
#performance
#developer-experience-dx
#just-in-time-jit
#fibers
Summarized using AI

Closing Keynote

by Aaron Patterson

In his closing keynote at RailsConf 2024, Aaron Patterson, affectionately referred to as the 'fun uncle' of Ruby on Rails, shared his thoughts on the future of Rails development and performance enhancements within the Ruby ecosystem. He began the presentation with intriguing random facts about Ruby, highlighting its use of pseudo-random numbers and the capabilities of controlling randomness with the srand method.

Key points discussed throughout the talk included:

- Reflections on Rails Engines and Active Record: Aaron planned to discuss Rails engines but shifted focus to personal reflections on the conference and the success stories shared by speakers like Nadia and Erina.

- Developer Experience: He emphasized the importance of developer experience in Ruby and Rails, discussing his work at Shopify and mentioning initiatives like the development of language servers and the Ruby LSP.

- Performance Improvements in Rails:

- Upcoming changes include enabling Just-In-Time (JIT) compilation by default in production for performance improvements of up to 15%, contingent upon workload.

- Plans to introduce a Ruby tag helper in Rails for better support of HTML pronunciation features.

- Concurrency and CPU vs. IO: Aaron provided insights into managing concurrency in applications, advising on the distinction between CPU-bound and IO-bound operations. He recommended strategies for optimizing performance through threads, fibers, and refactoring code for better speed.
- Ruby 3.4 Advantages: Discussion on enhancing efficiency with a new register allocator aimed at improving memory usage, alongside developments in Protobuf to outpace existing libraries in terms of speed.

- Object Shapes and Optimization: The introduction of object shapes in Ruby 3.2 and inline caches in Ruby 3.3 to enhance performance by reducing instance variable lookup times and improving memory management through functional data structures like red-black trees.

In conclusion, Aaron celebrated the community and the advancements being made in Rails, reinforcing the belief that the current era of Rails development is the most exciting. He expressed his gratitude to the audience for their engagement, and the importance of continuing the conversation and collaboration within the Rails community as they move forward.

00:00:10.800 To close the day, our final speaker is none other than the inimitable Aaron Patterson.
00:00:18.080 Woohoo!
00:00:25.000 Aaron is the self-proclaimed ‘fun uncle’ of Ruby on Rails. I think he said cool uncle, yes, sorry I forgot that detail.
00:00:30.960 He is a prototypical Ruby and Rails developer, even though he mainly works with C and Rust these days, and he's an all-around lovely person. Please give a round of applause for Aaron!
00:00:54.600 I love you! Oh, thank you! Thank you, Wayne.
00:01:00.320 Thank you, thank you. Thank you, Andy. I'm not the cool uncle, I’m just here to make that clear; I’m the fun uncle.
00:01:07.200 I want to start off today with a few random facts. The first random fact I want to give you is that Ruby actually uses pseudo-random numbers, meaning it’s not perfectly random.
00:01:18.720 The next fact is that you can use `srand` to control your random numbers, which is useful if you need stable random numbers.
00:01:27.119 My next random fact is that you can instantiate a new random object using the Random class.
00:01:32.280 The reason I wanted to share these random facts today is because I feel like random facts these days are not normally distributed.
00:01:38.320 I'm really happy to be here today; it’s great to be in the Motor City. I heard that this is where Rails engines were invented.
00:01:44.479 I was going to talk about Rails engines but decided instead to reflect on some Active Record reflections.
00:01:51.600 I hope you're all prepared for my coverage—just kidding! I really enjoyed this conference. It was great to see Nadia's opening talk about her company, The StoryGraph.
00:02:04.439 Her presentation was inspiring. While I’m not particularly interested in starting a company, I felt inspired to think about it after her talk.
00:02:12.519 I really enjoyed the way she used graphs to tell the story of her company—a story graph, if you will.
00:02:23.800 Erina's talk was also incredible. I loved hearing stories about the different startups using Ruby on Rails to build successful businesses.
00:02:29.040 It made me feel good hearing these success stories, and I appreciated the feedback she provided on how we can improve Ruby and Rails.
00:02:35.200 I think it's really important that our community is encouraged to be loud about the framework that we use and love.
00:02:43.239 However, I have to admit that some of the feedback was hard for me to take as a member of the Rails Core Team.
00:02:51.600 I also enjoyed John's talk on the profiler. After his presentation, I used his profiler to shave about 10 minutes off this presentation.
00:03:05.840 When he first put up his website, he sent me a direct message saying to check out his P.F.P., and I was extremely confused.
00:03:14.880 It turned out he meant his profiler page. Let's move on.
00:03:20.520 I really enjoyed hack day. It was a ton of fun! I helped some folks add a callback to Active Storage, so we could know when a file had been uploaded.
00:03:32.000 I also helped someone run Lobsters, where we were tracking down a memory leak in his application, which I think is awesome because Lobsters is a Rails application.
00:03:44.520 To reiterate Erina's point about being loud, I want to be loud on this stage about my love for Rails.
00:03:57.120 It’s my very first time in Detroit—my first time in Michigan—and I'm so happy to be here!
00:04:05.200 I tried to do all the local Detroit stuff. I rode the People Mover, and I heard there’s a statue built of our most beloved Ruby linter, RuboCop.
00:04:11.600 And it’s true—there is a RuboCop statue here, though I haven't seen it since it’s locked in someone's garage.
00:04:18.480 I also enjoyed some Detroit-style pizza, which was delicious, and I learned that Coney Island is not in New York!
00:04:27.120 I went to Coney Island and had a Coney Island Hot Dog, which was delicious.
00:04:33.840 There are some things I haven’t experienced yet; I haven't been to a party store, which I’ve heard are all the rage.
00:04:39.960 I also have yet to visit our neighbors to the south—Canada!
00:04:49.360 My name is A. P. and I go by Tender Love online. I started a live stream on YouTube mainly to amortize the cost of my green screen.
00:04:58.000 I’m really proud of this live stream because they don’t just give them to anybody! Please join me for the live stream.
00:05:06.200 Don't forget to like, subscribe, and comment below! It really helps the channel grow.
00:05:16.040 We’re only about 97,000 subscribers, almost there!
00:05:22.720 I mostly stream about Ruby and Rails internals, and I will take requests.
00:05:29.520 If there's anything specific you'd like to learn about regarding Ruby or Rails internals, let me know.
00:05:38.000 I work for a tiny startup called Shopify on the Ruby and Rails infrastructure team.
00:05:45.680 Our team has about 36 people, which I verified by looking at the number of people in the Slack channel, so I’m not very sure!
00:05:55.200 We’re divided into three different teams: the Ruby infrastructure team that focuses on the Ruby language,
00:06:02.760 the Rails infrastructure team that deals with the Rails side of things, and the Ruby DX team focusing on developer experience.
00:06:10.239 You might think it’s a bit weird to have those three teams, but it’s cohesive because developer experience works closely with.
00:06:15.680 We deliver the best experiences possible for developers at Shopify and those outside it.
00:06:22.440 For example, the DX team works on language servers, develops the Ruby LSP, and Rails plugins for it.
00:06:33.600 They also do a lot of work on IRB; any areas where developers interact with Ruby, this team is involved.
00:06:42.560 One great example of collaboration is the new gem called Prism, introduced in Ruby 3.3.
00:06:50.760 This gem allows us to do static analysis of code, get error messages, and perform transformations.
00:06:59.280 I talked a lot about developer experience last year, and while it may seem last year's topic, it is still relevant.
00:07:08.000 This year, I want to discuss specifically the speed of Ruby and Rails.
00:07:16.000 The first thing I want to talk about are some upcoming changes in Rails.
00:07:23.840 First, has anyone heard of the Ruby tag in HTML? A couple folks in the audience!
00:07:31.839 This is just an HTML tag used for pronunciation, particularly displaying kanji characters with accompanying pronunciation text.
00:07:40.520 We’re actually adding a Ruby tag helper to Rails, which is exciting!
00:07:47.040 The first feature I want to discuss is enabling JIT in production by default.
00:07:54.760 In future versions of Rails, we will enable it by default in production environments, and we’re currently using that at work!
00:08:00.800 We're observing about a 15% performance improvement and have heard reports of even better results depending on the workload.
00:08:11.360 If you’re in a non-memory-constrained environment, this can be essentially free performance.
00:08:22.720 To enable it today, just generate this initializer and make sure to copy it into your application.
00:08:31.440 What's nice about this initializer is we wait until after the application has booted to enable, reducing memory usage.
00:08:38.640 With this, we're able to delay the JIT during boot time.
00:08:44.760 The next feature is an option to disable connection caching.
00:08:50.560 It may seem a bit odd, but the purpose is to facilitate migration to a block form to help manage connections better.
00:09:00.760 If that method is used, it will raise an exception to guide users toward the new approach.
00:09:09.360 The reason behind this change caters to the application’s concurrency and parallelism.
00:09:20.000 For example, if we manage our database connections more intelligently, we can reduce the number of open connections.
00:09:30.160 Ruby is on a journey to being more efficient overall. CPU-bound code limitations exist in CRuby due to its single-threaded nature.
00:09:39.760 While IO-bound code can run in parallel, CPU-bound calculations can't be sped up using threads or fibers.
00:09:47.760 If you build a service that calculates Fibonacci numbers, that code will not improve speed using threads or fibers.
00:09:56.760 Instead, consider calling out to another service to avoid CPU-bound blocking.
00:10:05.760 This means using threads to wrap IO will allow your code to run concurrently.
00:10:12.760 Using fiber for IO won’t yield speed benefits as they require cooperative scheduling.
00:10:18.960 For high concurrency, choosing fibers with an appropriate library can be beneficial.
00:10:25.319 I’ll provide guidelines for using threads or fibers based on CPU-bound and IO-bound operations.
00:10:33.919 If you have a CPU-bound problem, refactor your code.
00:10:43.920 For simple database queries, use threads or better yet, the load async method for queries to run in background.
00:10:51.800 If you find yourself managing many connections, use fibers.
00:10:59.840 Next, I want to talk about our work with the Ruby side of things, especially around JIT.
00:11:08.080 In the Rails app we've targeted, we want to see speed improvements for production.
00:11:15.839 In Ruby 3.4, we are working on a register allocator to improve local variable memory usage.
00:11:22.720 By retaining values in registers tightly alongside the CPU, we improve the operation speed.
00:11:30.480 However, most focus isn’t on benchmarks but rather on improving the Rails ecosystem as a whole.
00:11:42.080 A noteworthy achievement is the development of the Protobuf library, leading to significant performance gains.
00:11:49.920 Coming up, our performance claims are nine times faster than Google's Protobuff library.
00:11:56.720 We're continuing to enhance Ruby's capabilities to keep developers within Ruby.
00:12:04.160 Next, I want to elaborate on object shapes, initially introduced in Ruby 3.2.
00:12:13.200 Instance variables stored in arrays are indexed, and object shapes serve to map names to indices.
00:12:22.560 When multiple objects share the same variables, we can increase performance by setting those variables in similar order.
00:12:30.000 To streamline instance variable checks, we introduced inline caches.
00:12:39.520 Checks through caches can improve efficiency by reducing lookups to a minimum.
00:12:48.720 Our work in Ruby 3.3 concerning these caches led to significant gains.
00:12:57.040 We examined cache misses happening from improper query handling or variable naming.
00:13:06.960 The solution was to optimize query structures, leading to improved performance.
00:13:12.240 Our team is excited to apply novel data structures in improving memory management.
00:13:22.480 We introduced a functional red-black tree to give faster lookups and greater efficiency.
00:13:30.160 I appreciate the concern for performance; we strive to optimize every element.
00:13:39.680 Our implementation efforts are building towards a swift Ruby performance future.
00:13:49.360 As we transition into the thoughts about concurrency and CPU rights, do keep in mind the techniques presented.
00:13:58.720 I've delved into many details today about performance, caching, and active handling of IO versus CPU.
00:14:07.920 Thank you for joining me on this performance discussion. It’s inspiring sharing these thoughts with the community.
00:14:15.040 Now I want to wrap up, reflecting on being a Rails developer and the community we have.
00:14:24.880 Having attended RailsConf for over 10 years, I find it rewarding.
00:14:33.600 Today, I believe the best era for Rails development is happening right now!
00:14:41.840 With every iteration of Rails, we grow more efficient and have more fun!
00:14:47.600 While I am sad to see that next year will be the last RailsConf, I look forward to this.
00:14:54.920 It’s a pleasure to be part of such a friendly and enriching community.
00:15:04.000 After today, we can continue engaging in the conversation, looking to future opportunities.
00:15:14.960 Thank you so much for attending; it’s been an honor to present to all of you today!
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