[erlang-questions] [ANN] Syn 1.0.0 & PubSub branch

Roberto Ostinelli <>
Sun Mar 6 13:24:04 CET 2016

On Sun, Mar 6, 2016 at 12:54 PM, Loïc Hoguin <> wrote:

> Cheers!
> What would you say would be the advantages of Syn over Gproc?
> And for process groups over cpg?

Hello Loïc!
I wrote an article with comparisons between global, pg2, gproc and cpg
which led me to write Syn here:


Gproc is great! However, to my understanding it's main purpose is not to be
distributed. I found instabilities when dealing with Gproc in a distributed
environment, possibly because the distributed part is based on gen_leader.
The README in Gproc’s Github page clearly depicts it as being an “Extended
process dictionary”; it just felt that the distributed part hasn’t been the
primary focus in the development of this library.

Ulf has said he wanted to use locks_leader, but the branch is still frozen
to some years ago:

I fear this will take us down the rabbit hole, but here it goes for CPG:
I've seen it first hand and I've had reports [1] that it might reach
bottlenecks when using a single scope. The author acknowledges and
recommends using multiple scopes, however even if I understand them, I
don’t care about using them (I feel I shouldn't be dealing with extra
complications to circumvent lib limitations).

Hope this clears up :)


[1] For instance:
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