OTP 21.3 release contains a few improvements in SSL library
- The Reason part of the error return from the functions connect and handshake has a better and documented format. This is a potential incompatibility. See the documentation.
- Refactoring of state handling has improved the TLS application data throughput and reduced CPU overhead
- Code optimizations has reduced CPU load for encryption/decryption, especially for Erlang's distribution protocol over TLS