[zeromq-dev] Can I prevent zeromq from occupying file descriptors?

Alexander Poddey alexander.poddey at gmx.net
Tue Jul 19 18:12:06 CEST 2016


Hmm,

on linux, the number of file descriptors per process is limited (typically 
to 1024). The total limit on my machine (kernel limit is ~734 000 opened 
files).

This means a process can accept only 1024 connections?!?

I can tweak the limit as super user of that machine; this however is no good 
solution. 
Think of my agent simulation running on a server where I'm not root. Then 
each process can accept only 1024 connections which is way to few... 

I wonder why zmq needs a file descriptor per connection...

Alexander



Doron Somech wrote:

> I'm  not sure I  understand,  each file descriptor is a socket.  When
> zeromq accept tcp socket another file descriptor is created. OS should be
> able to manage thousands and tens of thousand open descriptor.
> 
> On Jul 19, 2016 6:56 PM, "Alexander Poddey" <alexander.poddey at gmx.net>
> wrote:
> 
>>
>> Essentially, the question is:
>> why does ZMQ consume file descriptors at all?
>>
>>
>>
>>
>> > Hi,
>> >
>> > I have a setup in C++ on linux where a master process is setting up a
>> > ZMQ_ROUTER and then forks many child processes, which then connect to
>> that
>> > router (tcp protocol).
>> > Whenever a child zmq_connect's to the master, a file descriptor is
>> > occupied (and assigned to the master process). They get free'ed fine
>> > when the connection is close.
>> >
>> > This however limits the number of interacting processes to the number
>> > of allowed file descriptors (per process). For me (linux), this
>> > currently is 1024, which is way to small for my intended use
>> > (multi-agent / swarm simulation).
>> >
>> > Can I prevent this behaviour?
>> > In my mesaging architecture, each agent connects to 6 sockets, so with
>> 100
>> > agents I end up with 600 occupied file descriptors :-(
>> >
>> > Alexander
>> >
>> >
>> > _______________________________________________
>> > zeromq-dev mailing list
>> > zeromq-dev at lists.zeromq.org
>> > http://lists.zeromq.org/mailman/listinfo/zeromq-dev
>>
>>
>> _______________________________________________
>> zeromq-dev mailing list
>> zeromq-dev at lists.zeromq.org
>> http://lists.zeromq.org/mailman/listinfo/zeromq-dev





More information about the zeromq-dev mailing list