[rabbitmq-discuss] RabbitMQ on NetBSD

[Matthias Radestock]

There have been some reports of people running into problems starting 
RabbitMQ on NetBSD, with errors in the logs like

   application: os_mon
   exited: {shutdown,{os_mon,start,[normal,[]]}}
   type: temporary

and

   {unsupported_os,{unix,netbsd}}

I had a brief look into this and it appears that the root cause is in 
Erlang/OTP's cpu_sup code, the internals of which match on the Unix 
flavor and only accept sunos, linux, darwin, freebsd, openbsd, irix64, irix.

RabbitMQ uses cpu_sup's load monitoring to redirect clients to less 
loaded hosts in a clustered setup. It copes with cpu_sup not being 
available by falling back on other (less accurate) statistics.

So one way around the startup problem on NetBSD (and other Unix flavours 
that are unsupported by cpu_sup) is to disable cpu_sup in the 
rabbitmq_server startup script by changing the line
     -os_mon start_cpu_sup true \
to
     -os_mon start_cpu_sup false \

I haven't got a NetBSD box handy to test this, so if anybody can confirm 
that the above works please let the list know.


Regards,

Matthias.