[erlang-questions] PID recycling

Raimo Niskanen <>
Mon Sep 8 13:48:48 CEST 2008

Firstly. Please do not send HTML code to this list.
It is very hard to read for some (at least me).

On Fri, Sep 05, 2008 at 02:08:22PM +0200, Zoltan Peter Toth wrote:
> Question: how is the last used incarnation stored and when are values recycled
> ? (on Linux)
> Is there any way to change the cycling range ?
> Just for my curiosity :)
> Br,
>     Zoltan

The incarnation aka "Creation" is stored in EPMD, the Erlang
Port Mapper Daemon, that is external to all nodes.
It cycles 1,2,3 then round to 1 again. You can not change it.
It is platform independent. An undistributed node has creation 0.
Creation 0 is also used for dirty tricks having the meaning
of the current creation.

We have had plans to change it from 2 bits to 32 but it would
hit hard on erl_interface and applications using it.


/ Raimo Niskanen, Erlang/OTP, Ericsson AB

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