Latest rabbit_common support OTP 22/23/24

[vkatsuba]

Hi All,

The mirrored_supervisor.erl of theatest version of rabbit_common can working only on OTP versions 23 and 24, this is related to changes pg2 => pg for OTP 24 compatibility . The main issue is that the pg module was added in OTP 23 and not exist in OTP 22. So, currently latest version of rabbit_common is supported OTP 23/24.

Regards,
--V

[vkatsuba]

Fix #3308. But looks like also need apply this changes to 3.8.X version too.

[michaelklishin]

I'm sorry but we are not interested in adding this kind of complexity. Erlang 22 is no longer supported by RabbitMQ. Those who need to use rabbit_common on Erlang 22 can use an older version.

[michaelklishin]

By the way, pg and pg2 may seem to be almost a drop-in replacement of one another but they are not. pg2 relies on distributed locks and pg is strongly eventually consistent by design. This can matter a great deal. I would not recommend anyone to assume that a macro shim would be safe to use or provide in a library.

[vkatsuba]

@michaelklishin thanks for code review and for providing explanation. Nevertheless it sounds sad, a lot of libraries try to support the last three versions and this means that everyone who uses this library will have to make a choice stop support OTP 22 or not etc. But in any case, many thanks for info.

Regards,
--V