Erlang OTP 21.2 is released
Written by Henrik, 12 Dec 2018

OTP 21.2

Erlang/OTP 21.2 is the second service release for the 21st major release with, improvements as well as a few features!




  • Public key methods: ssh-ed25519 and ssh-ed448 added. Requires OpenSSL 1.1.1 or later as cryptolib under the OTP application


  • ssl now uses active n internally to boost performance. Old active once behaviour can be restored by setting a application variable.

ERTS, Kernel:

  • New counters and atomics modules supplies access to highly efficient operations on mutable fixed word sized variables.
  • New module persistent_term!. Lookups are in constant time! No copying the terms!
  • New pollset made to handle sockets that use {active, true} or {active, N}. Polled by a normal scheduler!

  • No more ONESHOT mechanism overhead on fds! Only on Linux and BSD

For a full list of details see:

Pre built versions for Windows can be fetched here:

Online documentation can be browsed here:

The Erlang/OTP source can also be found at GitHub on the official Erlang repository, Here: OTP-21.2

Please report any new issues via Erlang/OTPs public issue tracker

We want to thank all of those who sent us patches, suggestions and bug
Thank you!
The Erlang/OTP Team at Ericsson