[erlang-questions] Setting compatibility mode via +R

[Devangana Tarafdar]

Thank you for the link, I will go through this.

-Devangana



On Mon, Jul 15, 2013 at 2:11 PM, Michael Loftis <mloftis@REDACTED> wrote:

> I don't believe the distribution protocol has changed since like R6 or so.
>
> http://www.erlang.org/doc/apps/erts/erl_dist_protocol.html
>
> On Mon, Jul 15, 2013 at 12:08 PM, Devangana Tarafdar
> <devangana@REDACTED> wrote:
> > Hello,
> >
> > I am experimenting with the +R <release number> emulator flag as
> described
> > in the erl  man page ( http://www.erlang.org/doc/man/erl.html) and I am
> > confused about when I should be using this and also what happens if I do
> not
> > use this when communicating between 2 nodes from different releases.
> >
> > "  +R ReleaseNumber
> >
> > Sets the compatibility mode.
> >
> > The distribution mechanism is not backwards compatible by default. This
> > flags sets the emulator in compatibility mode with an earlier Erlang/OTP
> > release ReleaseNumber. The release number must be in the range <current
> > release>-2..<current release>. This limits the emulator, making it
> possible
> > for it to communicate with Erlang nodes (as well as C- and Java nodes)
> > running that earlier release.
> >
> > Note: Make sure all nodes (Erlang-, C-, and Java nodes) of a distributed
> > Erlang system is of the same Erlang/OTP release, or from two different
> > Erlang/OTP releases X and Y, where all Y nodes have compatibility mode
> X."
> >
> > This is what I am doing when setting up 2 nodes from release 13B03 and
> 16B.
> > The release numbers difference is greater than 2 so I cannot use the +R
> flag
> > anyway but the nodes have no problems communicating without the flag. I
> was
> > expecting that the nodes would not be able to connect at all but clearly
> I
> > am wrong.
> >
> > #startup
> >
> > #first node
> > erl -name node_a -setcookie x
> > Erlang R13B03 (erts-5.7.4) [source] [64-bit] [smp:4:4] [rq:4]
> > [async-threads:0] [hipe] [kernel-poll:false]
> >
> > Eshell V5.7.4  (abort with ^G)
> > (node_a@REDACTED)1> erlang:system_info(otp_release).
> > "R13B03"
> >
> > #second node
> > downloads/otp_src_R16B/bin/erl   -name node_b -setcookie x
> > Erlang R16B (erts-5.10.1) [source] [64-bit] [smp:4:4] [async-threads:10]
> > [kernel-poll:false]
> >
> > Eshell V5.10.1  (abort with ^G)
> > (node_b@REDACTED)1>  erlang:system_info(otp_release).
> > "R16B"
> >
> >
> > # subsequent session
> > (node_b@REDACTED)3> net_adm:ping('node_a@REDACTED').
> > pong
> >
> >
> > (node_a@REDACTED)2> nodes().
> > ['node_b@REDACTED']
> > (node_a@REDACTED)5> net_kernel:disconnect('node_b@REDACTED').
> > true
> > (node_a@REDACTED)6> nodes().
> > []
> > (node_a@REDACTED)7> net_adm:ping('node_b@REDACTED').
> > pong
> > (node_a@REDACTED)8>
> >
> >
> > Thank you for any help in interpreting this.
> >
> > Devangana
> >
> >
> >
> >
> >
> > _______________________________________________
> > erlang-questions mailing list
> > erlang-questions@REDACTED
> > http://erlang.org/mailman/listinfo/erlang-questions
> >
>
>
>
> --
>
> "Genius might be described as a supreme capacity for getting its possessors
> into trouble of all kinds."
> -- Samuel Butler
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://erlang.org/pipermail/erlang-questions/attachments/20130715/12ced396/attachment.htm>