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Some bigger details why phoenix is so fast despite erlang being a "slow" language: - macros: fancy syntax and "magic" can be resolved at compile-time. Less wor

Some bigger details why phoenix is so fast despite erlang being a "slow" language: - macros: fancy syntax and "magic" can be resolved at compile-time. Less work to do on runtime. - templates: they get handled at compile-time, too, resulting in functions with blobs of binaries. This matters a lot, since a specific template-binary exists only once throughout the application and gets re-used whenever needed. This way you get near instant templating, instead of the usual string processing on every request. - dispatching code like the routing that must be done on every request is like rails a DSL, but actually a macro, that gets compiled down to basic pattern matches, which is extremely fast. - the concurrency model is extremely lightweight, handling more requests and/or doing more stuff per request is much more efficient hardware-wise. Indirect performance gain. Just a few points that have a very noticeably impact, there are probably more. It boils down to the erlang vm's concurrency and pattern matching performance, plus elixir's compile-time macros and the fact that they treat strings as immutable binaries.

davidw 10y ago
> macros All well and good, but Erlang/beam code is not that fast. > templates Ruby's templates are parsed into code that stays in memory, too, so it's not like they're re-parsed each and every time. > routing Perhaps clever use of pattern matching helps here. But my point is: someone should dissect these things in a real-world-ish application to see what's actually true. > concurrency Yes, but let's be precise. Everyone knows Erlang's concurrency is way better than Ruby's. The claim was 'fast' though. As well as maintainable, which seems curious given that there are no really old Phoenix apps out there.
- anonyfox 10y ago
  > but Erlang/beam code is not that fast. True, no doubt. You wanted a comparison why phoenix is faster than rails. And simply doing things at compile time reduces work at runtime. In Ruby, all Metaprogramming must be done at runtime, for example via method_missing trickery (been there, done that). > Ruby's templates are parsed into code that stays in memory, too, so it's not like they're re-parsed each and every time. This is actually not the same. A single immutable blob of binary (elixir strings) which is shared throughout the whole application can leverage hardware caching better. Jose could answer this probably better than I can do. > someone should dissect these things in a real-world-ish application to see what's actually true. Moz.com recently had fun with Elixir [1]. You may also have a look at https://www.youtube.com/watch?v=OxhTQdcieQE https://www.youtube.com/watch?v=OxhTQdcieQE from latest RailsConf. > The claim was 'fast' though Well at least I know that BEAM processes are far lighter than eg: goroutines. Also there is a per-process GC, so no "stop the world", much smaller units for individual collects, and when a process finishes before the heap grows full, it can be discarded directly. > maintainable, which seems curious given that there are no really old Phoenix apps out there Fair enough. Personally I'd not wait until a software stack is a decade old before even considering it. I have at least worked on Elixir/Phoenix projects for many months now on-off with multiple colleagues, and it was/is still pure joy. Aesthetically pleasing syntax helps (broken window syndrome I guess), plus functional programming style in general, plus phoenix' foundation in "plug" and the clear modularity. "Let it crash" with supervisors also is incredibly robust, and robustness in itself leads to less maintenance costs. --- [1] https://moz.com/devblog/moz-analytics-db-free/ https://moz.com/devblog/moz-analytics-db-free/
  - davidw 10y ago
    All good points. As I keep saying, I'm an Erlang fan. I actually used it at my last job, and have used it on and off since 2004-ish. It definitely has some advantages, but I'm just curious where it's actually beating Rails, and with what kinds of workloads and test methodology and so on. Stuff like "Erlang processes are lighter" matters in some contexts, but not in a straight up speed contest. It matters a lot when you start trying to handle a bunch of concurrent connections, so maybe that's where we're getting some of the claims from.
    - anonyfox 10y ago
      I'd say you really should have a look into https://www.youtube.com/watch?v=OxhTQdcieQE https://www.youtube.com/watch?v=OxhTQdcieQE . A really great presentation, including numbers and real world backup data, plus conceptual overviews.
      - davidw 10y ago
        It's pretty good, but a bit hype-y. Functional programming is not an 'antidote' to having to go back and read old code or necessarily understanding it easily. It references this: http://sorentwo.com/2016/02/02/caching-what-is-it-good-for.html http://sorentwo.com/2016/02/02/caching-what-is-it-good-for.h... Which is interesting, but I don't see source code. 1.5-2X is pretty believable, but quite a bit less than "12 times" - which someone quoted here.
        anonyfox 10y ago
        I can personally confirm above 10x improvements over rails, but can't Share the code :) Depends on what you're doing though. Seems to excel when having low CPU intensive workloads but high traffic pressure from my experience.

davidw 10y ago

> macros All well and good, but Erlang/beam code is not that fast. > templates Ruby's templates are parsed into code that stays in memory, too, so it's not like they're re-parsed each and every time. > routing Perhaps clever use of pattern matching helps here. But my point is: someone should dissect these things in a real-world-ish application to see what's actually true. > concurrency Yes, but let's be precise. Everyone knows Erlang's concurrency is way better than Ruby's. The claim was 'fast' though. As well as maintainable, which seems curious given that there are no really old Phoenix apps out there.

anonyfox 10y ago
> but Erlang/beam code is not that fast. True, no doubt. You wanted a comparison why phoenix is faster than rails. And simply doing things at compile time reduces work at runtime. In Ruby, all Metaprogramming must be done at runtime, for example via method_missing trickery (been there, done that). > Ruby's templates are parsed into code that stays in memory, too, so it's not like they're re-parsed each and every time. This is actually not the same. A single immutable blob of binary (elixir strings) which is shared throughout the whole application can leverage hardware caching better. Jose could answer this probably better than I can do. > someone should dissect these things in a real-world-ish application to see what's actually true. Moz.com recently had fun with Elixir [1]. You may also have a look at https://www.youtube.com/watch?v=OxhTQdcieQE https://www.youtube.com/watch?v=OxhTQdcieQE from latest RailsConf. > The claim was 'fast' though Well at least I know that BEAM processes are far lighter than eg: goroutines. Also there is a per-process GC, so no "stop the world", much smaller units for individual collects, and when a process finishes before the heap grows full, it can be discarded directly. > maintainable, which seems curious given that there are no really old Phoenix apps out there Fair enough. Personally I'd not wait until a software stack is a decade old before even considering it. I have at least worked on Elixir/Phoenix projects for many months now on-off with multiple colleagues, and it was/is still pure joy. Aesthetically pleasing syntax helps (broken window syndrome I guess), plus functional programming style in general, plus phoenix' foundation in "plug" and the clear modularity. "Let it crash" with supervisors also is incredibly robust, and robustness in itself leads to less maintenance costs. --- [1] https://moz.com/devblog/moz-analytics-db-free/ https://moz.com/devblog/moz-analytics-db-free/
- davidw 10y ago
  All good points. As I keep saying, I'm an Erlang fan. I actually used it at my last job, and have used it on and off since 2004-ish. It definitely has some advantages, but I'm just curious where it's actually beating Rails, and with what kinds of workloads and test methodology and so on. Stuff like "Erlang processes are lighter" matters in some contexts, but not in a straight up speed contest. It matters a lot when you start trying to handle a bunch of concurrent connections, so maybe that's where we're getting some of the claims from.
  - anonyfox 10y ago
    I'd say you really should have a look into https://www.youtube.com/watch?v=OxhTQdcieQE https://www.youtube.com/watch?v=OxhTQdcieQE . A really great presentation, including numbers and real world backup data, plus conceptual overviews.
    - davidw 10y ago
      It's pretty good, but a bit hype-y. Functional programming is not an 'antidote' to having to go back and read old code or necessarily understanding it easily. It references this: http://sorentwo.com/2016/02/02/caching-what-is-it-good-for.html http://sorentwo.com/2016/02/02/caching-what-is-it-good-for.h... Which is interesting, but I don't see source code. 1.5-2X is pretty believable, but quite a bit less than "12 times" - which someone quoted here.
      - anonyfox 10y ago
        I can personally confirm above 10x improvements over rails, but can't Share the code :) Depends on what you're doing though. Seems to excel when having low CPU intensive workloads but high traffic pressure from my experience.