[erlang-questions] If you make WhatsApp today...

[Mikael Pettersson]

Kenneth Lakin writes:
 > On 10/12/2015 02:13 AM, Richard Carlsson wrote:
 > >     As I understand it, Klarna will publish the leveldb backend (the
 > >     pgsql backend was an experiment, so I don’t know about that).
 > 
 > The Mnesia leveldb backend relies on mnesia_ext, which is a patch to
 > Mnesia, right?
 > 
 > If I'm not wrong about that, will one be required to make use of a
 > patched Erlang/OTP, or are there plans to get the patch into Erlang, or
 > -somehow- make it a library that can be included in one's software?

There is an open P.R. to include mnesia_ext in OTP, and we have
published versions for R15, R16, and 17 on Klarna's github for those
that prefer stable releases over bleeding edge.  The R15 and R16
versions have had substantial testing in production.

You can bundle a patched OTP, or just a patched mnesia, with your
application (mnesia itself is just a library, and mnesia_ext doesn't
patch the VM).

Our Erlang systems use locally patched stable OTP releases anyway, so
adding one more patch for mnesia_ext is no big deal.