12 ms·

Erlang OTP 22.0 is released

315 points by ramchip 7y ago

rapsey 7y ago
This looks like the biggest major release in years.
- pselbert 7y ago
  They have a major release every year or so, the last one was June of last year. They will release features in point releases though, for example Counters was released in 21.1 and Persistent Term was released with 21.2.
deleted 7y ago
[deleted]
yingw787 7y ago
Wow, congrats to the OTP contributors, this looks like a lot of work! I’ve heard that the BEAM VM byte code is not well documented (maybe in comparison to JVM bytecode), which is one reason that Elixir transpired to Erlang first; is this true?
- adamkittelson 7y ago
  I have no idea about the bytecode documentation, but Elixir is definitely not transpiled to Erlang.
  - Xixi 7y ago
    To be technically correct, Elixir is compiled into "Erlang Abstract Format, which is a standard representation of an Erlang AST using Erlang terms." [1] From there it compiles down to bytecode using Erlang tool chain. So saying that Elixir is transpiled to Erlang is incorrect: it compiles to Erlang AST. [1] https://medium.com/@fxn/how-does-elixir-compile-execute-code-c1b36c9ec8cf https://medium.com/@fxn/how-does-elixir-compile-execute-code...
    - bglusman 7y ago
      Hah, sorry, also posted a similar response in parallel but on parent! I had to google though, I couldn't remember if maybe Elixir used Core Erlang, I'm still a little fuzzy on where that's used and if any important relation to Erlang Abstract Form
- bglusman 7y ago
  Maybe you heard something about Elixir compiling to Erlang Abstract Form? http://erlang.org/doc/apps/erts/absform.html http://erlang.org/doc/apps/erts/absform.html
- lelf 7y ago
  That is not the reason. It makes sense to compile to Erlang AST representation and leverage all the power (codegen/optimisations/…) of Erlang compiler for free.
truth_seeker 7y ago
Congratulations. I wish BEAM could be as effective as or close to the performance of JVM for Numerical Computation.
- phoe-krk 7y ago
  Numerical computation is not and never was a priority for the BEAM. Reliability, network connectivity and efficiency for multiple processes were. If you want to leverage highly performant numerical code, I suggest to link against a native C library from BEAM using NIFs via http://erlang.org/doc/tutorial/nif.html http://erlang.org/doc/tutorial/nif.html or connect a C program to the Erlang network via http://erlang.org/doc/tutorial/cnode.html http://erlang.org/doc/tutorial/cnode.html
  - andy_ppp 7y ago
    What's preventing optimisations from being built for maths to be at least as fast as something like Numpy? Is it just the realtime nature of the BEAM makes it difficult? If you really like you can choose to compile things using HiPE which in my tests can make mathematical stuff about 10X faster... it sounds pretty unsupported these days though. Maybe just put messages on a queue and process them in golang or rust if you must have the performance, no need to let the BEAM have to handle such things directly and always good to measure where your bottlenecks are first.
    - phoe-krk 7y ago
      > What's preventing optimisations from being built for maths to be at least as fast as something like Numpy? Is it just the realtime nature of the BEAM makes it difficult? You have to take immutability and multi-processing into account. Each process has a separate heap as a design assumption, so if you want to pass data between them, you must copy. Data is immutable as another design assumption, and this means that if you want to change something in a bigger data structure, you also must copy. Theoretically, the compiler is free to optimize the latter - if it notices that some code can be safely optimized in a mutating way, it is free to do that, but then, someone needs to write that optimization - and the fact that this is not a priority for BEAM means that it is unlikely that someone will spend time to implement it if there are more pressing matters for them to do so. Then, not only it must be written, it must be proven that this optimization does not break anything.
deleted 7y ago
[deleted]
mikece 7y ago
Is there a "definitive" source for explaining the differences -- philosophical, architectural, performance -- between BEAM, JVM, V8, and other virtual machines targeted by programming languages? When I attempt to explain what makes BEAM interesting I default to comparing it to the JVM to explain "similar but different" analogies but I don't recall all of the sources from which I learned those analogies.
- mikece 7y ago
  One of the other analogies is to containers: processes in BEAM are as isolated from each other as applications running on different machines. They can pass messages to each other but they absolutely cannot access each other's memory... this was explained to me when I asked about running Elixir apps in Docker containers and the "Erlang old-timer" laughed and explained why it wasn't necessary.
teilo 7y ago
Nice optimizations, but note that it breaks HiPE.
- klibertp 7y ago
  Only if you use new BEAM features [EDIT: or new compiler optimizations... this could be hard to avoid, so using HiPE may indeed become hard/impossible for awhile... :(] in the module you want to HiPE-compile: > In OTP 22, HiPE (the native code compiler) is not fully functional. The reasons for this are: > There are new BEAM instructions for binary matching that the HiPE native code compiler does not support. > The new optimizations in the Erlang compiler create new combination of instructions that HiPE currently does not handle correctly. > If erlc is invoked with the +native option, and if any of the new binary matching instructions are used, the compiler will issue a warning and produce a BEAM file without native code. Source: http://erlang.org/download/otp_src_22.0.readme http://erlang.org/download/otp_src_22.0.readme (search for OTP-15596)
- alberth 7y ago
  Is HiPE not apart of Erlang core? I’m confused why they would release features that knowingly break other parts of Erlang core (ie HiPE)
  - troutwine 7y ago
    The relationship with HiPE is weird. It's probably better to consider HiPE as an alternative VM to BEAM which used to be faster in some kinds of computations -- especially numerical -- but had trade-offs in terms of memory consumption and compatibility. Different shops approach HiPE uniquely, but it was not uncommon to see HiPE used for tooling -- dialyzer especially -- but not end up in production. The original developers of HiPE have now moved on entirely or are focused more on introducing JIT capability to BEAM. The BEAM team are not the maintainers of HiPE and don't have the expertise to update it, meanwhile HiPE does not have a full-time, dedicated team behind it. I won't be surprised if HiPE gets split out from the default install in a few years if HiPE keeps falling behind.
    - 7y ago
klibertp 7y ago
Highlights: > In OTP 22 we have completely re-implemented the lower levels of the Erlang compiler. Meaning some performance improvements for bit syntax which in Erlang is used [EDIT: in some of the newer, external code; there are still many places where charlists are used] for strings. Some string BIFs got faster. This should translate directly to Elixir and its string handling functions performance. > OTP 22 comes with a new experimental socket API. The idea behind this API is to have a stable intermediary API that users can use to create features that are not part of the higher-level gen APIs. Other than the ease of extending the API there are some performance improvements, too. > PR1952 contributed by Kjell Winblad from Uppsala University makes it possible to do updated in parallel on ets tables of the type ordered_set. This has greatly increased the scalability of such ets tables that are the base for many applications, for instance, pg2 and the default ssl session cache. More concurrency, better performance. > In OTP 21.3 the culmination of many optimizations in the ssl application was released. For certain use-cases, the overhead of a using TSL has been significantly reduced. [...] The bytes per second that the Erlang distribution over TSL is able to send has been increased from 17K to about 80K, so more than 4 times as much data as before. Everything relying on ssl got faster. > On OTP 22 the logging facility for ssl has been greatly improved and there is now basic server support for TLSv1.3. Not sure about that, don't know the details of TLS. More/better logging is always welcome. > In order to deal with the head of line blocking caused by sending very large messages over Erlang Distribution, we have added fragmentation of distribution messages in OTP 22. This means that large messages will now be split up into smaller fragments allowing smaller messages to be sent without being blocked for a long time. You can send lots of data over to other Erlang nodes without chunking them yourself - other messages will still go through anyway. Great if you have such messages in your app. > Three new modules, counters, atomics, and persistent_term, were added in OTP 21.2. These modules make it possible for the user to access low-level primitives of the runtime to make some spectacular performance improvements. > For instance, the cover tool was recently re-written to use counters and persistent_term [...] now it uses counters and the overhead of running cover has decreased by up to 80%. > A fun (and possibly useful) use case for atomics is to create a shared mutable bit-vector. So, now we can spawn 100 processes and play flip that bit with each other More tools for performance optimization is always welcome. Shared bit vector is an impressive example, but I'm not sure what else could be done with the modules, I didn't read their docs yet. > In OTP 21.3, the version when all functions and modules were introduced was added to the documentation. Great. It's implemented for many other langs' docs and is useful. All the docs were regenerated and the info about the version which introduced them was added to all the functions all over the place. > In OTP 22 a new documentation top section called Internal Documentation has been added to the erts and compiler applications. The sections contain the internal documentation that previously only has been available on github so that it easier to access. Better docs on internals is always a good thing. Could potentially save some work for other OTP langs implementers, including Elixir. > Each major OTP release wouldn’t be complete without a set of memory allocator improvements and OTP 22 is no exception. The ones with the most potential to impact your applications are PR2046 and PR1854. Both of these optimizations should allow systems to better utilize memory carriers in high memory situations allowing your systems to handle more load. Good. (not sure what else I could say here...) Source: http://blog.erlang.org/OTP-22-Highlights/ http://blog.erlang.org/OTP-22-Highlights/ In general, it looks like this release is focused on the optimization of many parts of the platform. Especially string handling improvements are welcome and will affect many Erlang-based (ie. including other OTP languages if I understand correctly) applications out there. That's good. Erlang being "slow" was always its weakest point which came up in nearly every discussion about Erlang. Great to see this is being actively addressed on many fronts. I'll definitely update my apps to use 22. Congrats and thanks to all contributors!
mothsonasloth 7y ago
Great to hear Outlaw Techno Psychobitch is pioneering on. https://www.youtube.com/watch?v=rRbY3TMUcgQ https://www.youtube.com/watch?v=rRbY3TMUcgQ
signa11 7y ago
blog from erlang/otp team, summarizing the major changes is quite useful as well: http://blog.erlang.org/OTP-22-Highlights/ http://blog.erlang.org/OTP-22-Highlights/
- truth_seeker 7y ago
  Also, Optimizations done for Named fun recursion, List subtraction with large operands, Lookahead in bit-syntax matching Ref link: http://blog.erlang.org/retired-pitfalls-22/ http://blog.erlang.org/retired-pitfalls-22/
- kitotik 7y ago
  > So with the network at our test site the max latency is decreased by roughly 99%, which is a nice improvement. Calling 50s to .4s a “nice improvement” is an awesome understatement!
mshockwave 7y ago
interestingly, i was not aware that erlang didn't use SSA in their compiler before this version

315 points by ramchip 7y ago

rapsey 7y ago

This looks like the biggest major release in years.

pselbert 7y ago
They have a major release every year or so, the last one was June of last year. They will release features in point releases though, for example Counters was released in 21.1 and Persistent Term was released with 21.2.

deleted 7y ago

[deleted]

yingw787 7y ago

Wow, congrats to the OTP contributors, this looks like a lot of work! I’ve heard that the BEAM VM byte code is not well documented (maybe in comparison to JVM bytecode), which is one reason that Elixir transpired to Erlang first; is this true?

adamkittelson 7y ago
I have no idea about the bytecode documentation, but Elixir is definitely not transpiled to Erlang.
- Xixi 7y ago
  To be technically correct, Elixir is compiled into "Erlang Abstract Format, which is a standard representation of an Erlang AST using Erlang terms." [1] From there it compiles down to bytecode using Erlang tool chain. So saying that Elixir is transpiled to Erlang is incorrect: it compiles to Erlang AST. [1] https://medium.com/@fxn/how-does-elixir-compile-execute-code-c1b36c9ec8cf https://medium.com/@fxn/how-does-elixir-compile-execute-code...
  - bglusman 7y ago
    Hah, sorry, also posted a similar response in parallel but on parent! I had to google though, I couldn't remember if maybe Elixir used Core Erlang, I'm still a little fuzzy on where that's used and if any important relation to Erlang Abstract Form
bglusman 7y ago
Maybe you heard something about Elixir compiling to Erlang Abstract Form? http://erlang.org/doc/apps/erts/absform.html http://erlang.org/doc/apps/erts/absform.html
lelf 7y ago
That is not the reason. It makes sense to compile to Erlang AST representation and leverage all the power (codegen/optimisations/…) of Erlang compiler for free.

truth_seeker 7y ago

Congratulations. I wish BEAM could be as effective as or close to the performance of JVM for Numerical Computation.

phoe-krk 7y ago
Numerical computation is not and never was a priority for the BEAM. Reliability, network connectivity and efficiency for multiple processes were. If you want to leverage highly performant numerical code, I suggest to link against a native C library from BEAM using NIFs via http://erlang.org/doc/tutorial/nif.html http://erlang.org/doc/tutorial/nif.html or connect a C program to the Erlang network via http://erlang.org/doc/tutorial/cnode.html http://erlang.org/doc/tutorial/cnode.html
- andy_ppp 7y ago
  What's preventing optimisations from being built for maths to be at least as fast as something like Numpy? Is it just the realtime nature of the BEAM makes it difficult? If you really like you can choose to compile things using HiPE which in my tests can make mathematical stuff about 10X faster... it sounds pretty unsupported these days though. Maybe just put messages on a queue and process them in golang or rust if you must have the performance, no need to let the BEAM have to handle such things directly and always good to measure where your bottlenecks are first.
  - phoe-krk 7y ago
    > What's preventing optimisations from being built for maths to be at least as fast as something like Numpy? Is it just the realtime nature of the BEAM makes it difficult? You have to take immutability and multi-processing into account. Each process has a separate heap as a design assumption, so if you want to pass data between them, you must copy. Data is immutable as another design assumption, and this means that if you want to change something in a bigger data structure, you also must copy. Theoretically, the compiler is free to optimize the latter - if it notices that some code can be safely optimized in a mutating way, it is free to do that, but then, someone needs to write that optimization - and the fact that this is not a priority for BEAM means that it is unlikely that someone will spend time to implement it if there are more pressing matters for them to do so. Then, not only it must be written, it must be proven that this optimization does not break anything.

deleted 7y ago

[deleted]

mikece 7y ago

Is there a "definitive" source for explaining the differences -- philosophical, architectural, performance -- between BEAM, JVM, V8, and other virtual machines targeted by programming languages? When I attempt to explain what makes BEAM interesting I default to comparing it to the JVM to explain "similar but different" analogies but I don't recall all of the sources from which I learned those analogies.

mikece 7y ago
One of the other analogies is to containers: processes in BEAM are as isolated from each other as applications running on different machines. They can pass messages to each other but they absolutely cannot access each other's memory... this was explained to me when I asked about running Elixir apps in Docker containers and the "Erlang old-timer" laughed and explained why it wasn't necessary.

teilo 7y ago

Nice optimizations, but note that it breaks HiPE.

klibertp 7y ago
Only if you use new BEAM features [EDIT: or new compiler optimizations... this could be hard to avoid, so using HiPE may indeed become hard/impossible for awhile... :(] in the module you want to HiPE-compile: > In OTP 22, HiPE (the native code compiler) is not fully functional. The reasons for this are: > There are new BEAM instructions for binary matching that the HiPE native code compiler does not support. > The new optimizations in the Erlang compiler create new combination of instructions that HiPE currently does not handle correctly. > If erlc is invoked with the +native option, and if any of the new binary matching instructions are used, the compiler will issue a warning and produce a BEAM file without native code. Source: http://erlang.org/download/otp_src_22.0.readme http://erlang.org/download/otp_src_22.0.readme (search for OTP-15596)
alberth 7y ago
Is HiPE not apart of Erlang core? I’m confused why they would release features that knowingly break other parts of Erlang core (ie HiPE)
- troutwine 7y ago
  The relationship with HiPE is weird. It's probably better to consider HiPE as an alternative VM to BEAM which used to be faster in some kinds of computations -- especially numerical -- but had trade-offs in terms of memory consumption and compatibility. Different shops approach HiPE uniquely, but it was not uncommon to see HiPE used for tooling -- dialyzer especially -- but not end up in production. The original developers of HiPE have now moved on entirely or are focused more on introducing JIT capability to BEAM. The BEAM team are not the maintainers of HiPE and don't have the expertise to update it, meanwhile HiPE does not have a full-time, dedicated team behind it. I won't be surprised if HiPE gets split out from the default install in a few years if HiPE keeps falling behind.
  - 7y ago

klibertp 7y ago

Highlights: > In OTP 22 we have completely re-implemented the lower levels of the Erlang compiler. Meaning some performance improvements for bit syntax which in Erlang is used [EDIT: in some of the newer, external code; there are still many places where charlists are used] for strings. Some string BIFs got faster. This should translate directly to Elixir and its string handling functions performance. > OTP 22 comes with a new experimental socket API. The idea behind this API is to have a stable intermediary API that users can use to create features that are not part of the higher-level gen APIs. Other than the ease of extending the API there are some performance improvements, too. > PR1952 contributed by Kjell Winblad from Uppsala University makes it possible to do updated in parallel on ets tables of the type ordered_set. This has greatly increased the scalability of such ets tables that are the base for many applications, for instance, pg2 and the default ssl session cache. More concurrency, better performance. > In OTP 21.3 the culmination of many optimizations in the ssl application was released. For certain use-cases, the overhead of a using TSL has been significantly reduced. [...] The bytes per second that the Erlang distribution over TSL is able to send has been increased from 17K to about 80K, so more than 4 times as much data as before. Everything relying on ssl got faster. > On OTP 22 the logging facility for ssl has been greatly improved and there is now basic server support for TLSv1.3. Not sure about that, don't know the details of TLS. More/better logging is always welcome. > In order to deal with the head of line blocking caused by sending very large messages over Erlang Distribution, we have added fragmentation of distribution messages in OTP 22. This means that large messages will now be split up into smaller fragments allowing smaller messages to be sent without being blocked for a long time. You can send lots of data over to other Erlang nodes without chunking them yourself - other messages will still go through anyway. Great if you have such messages in your app. > Three new modules, counters, atomics, and persistent_term, were added in OTP 21.2. These modules make it possible for the user to access low-level primitives of the runtime to make some spectacular performance improvements. > For instance, the cover tool was recently re-written to use counters and persistent_term [...] now it uses counters and the overhead of running cover has decreased by up to 80%. > A fun (and possibly useful) use case for atomics is to create a shared mutable bit-vector. So, now we can spawn 100 processes and play flip that bit with each other More tools for performance optimization is always welcome. Shared bit vector is an impressive example, but I'm not sure what else could be done with the modules, I didn't read their docs yet. > In OTP 21.3, the version when all functions and modules were introduced was added to the documentation. Great. It's implemented for many other langs' docs and is useful. All the docs were regenerated and the info about the version which introduced them was added to all the functions all over the place. > In OTP 22 a new documentation top section called Internal Documentation has been added to the erts and compiler applications. The sections contain the internal documentation that previously only has been available on github so that it easier to access. Better docs on internals is always a good thing. Could potentially save some work for other OTP langs implementers, including Elixir. > Each major OTP release wouldn’t be complete without a set of memory allocator improvements and OTP 22 is no exception. The ones with the most potential to impact your applications are PR2046 and PR1854. Both of these optimizations should allow systems to better utilize memory carriers in high memory situations allowing your systems to handle more load. Good. (not sure what else I could say here...) Source: http://blog.erlang.org/OTP-22-Highlights/ http://blog.erlang.org/OTP-22-Highlights/ In general, it looks like this release is focused on the optimization of many parts of the platform. Especially string handling improvements are welcome and will affect many Erlang-based (ie. including other OTP languages if I understand correctly) applications out there. That's good. Erlang being "slow" was always its weakest point which came up in nearly every discussion about Erlang. Great to see this is being actively addressed on many fronts. I'll definitely update my apps to use 22. Congrats and thanks to all contributors!

mothsonasloth 7y ago

Great to hear Outlaw Techno Psychobitch is pioneering on. https://www.youtube.com/watch?v=rRbY3TMUcgQ https://www.youtube.com/watch?v=rRbY3TMUcgQ

signa11 7y ago

blog from erlang/otp team, summarizing the major changes is quite useful as well: http://blog.erlang.org/OTP-22-Highlights/ http://blog.erlang.org/OTP-22-Highlights/

truth_seeker 7y ago
Also, Optimizations done for Named fun recursion, List subtraction with large operands, Lookahead in bit-syntax matching Ref link: http://blog.erlang.org/retired-pitfalls-22/ http://blog.erlang.org/retired-pitfalls-22/
kitotik 7y ago
> So with the network at our test site the max latency is decreased by roughly 99%, which is a nice improvement. Calling 50s to .4s a “nice improvement” is an awesome understatement!

mshockwave 7y ago

interestingly, i was not aware that erlang didn't use SSA in their compiler before this version