Re: Exceeding connection limit

[Roger Dingledine <arma@xxxxxxx>]

[Forwarding because John isn't subscribed at this address. Here's a more
detailed version of what I said in my other post. -RD]

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Date: Wed, 3 Dec 2008 13:59:41 -0700
From: "John Brooks" <special@xxxxxxxxxxxxxxxx>
To: or-talk@xxxxxxxxxxxxx
Subject: Re: Exceeding connection limit

This happens because the user tor is running as has a system-imposed limit
on the number of open file descriptors - one file descriptor corresponds to
one open file or socket. Many linux systems use '1024' as the default value
here - which is probably what yours is.

The solution to this problem is to raise that limit for tor's user; first by
figuring out what user tor is running as ('ps aux' will show this alongside
the process). Then, you or your sysadmin should raise the FD limit for that
user to something more reasonable for a socket-hungry application like tor.
I use 4096.

On many linux systems, this can be changed in /etc/security/limits.conf with
lines like:

toruser    hard   nofile    4096
toruser    soft    nofile    4096

I would recommend setting both the hard and soft limits (as shown), for
simplicity. There are other methods for other situations or systems, but
that should work on most forms of linux. Note that after changing this, you
will need to shut down tor, open a new terminal (important), and start tor
again for the new limit to take effect.

Also note that some VPS/VDS systems severely limit open sockets, so if
you're using one of those, you may not be able to use as many as tor would
want.

Hope that helps.

 - John Brooks

On Wed, Dec 3, 2008 at 1:49 PM, Praedor Atrebates <praedor@xxxxxxxxx> wrote:

> On Wednesday 03 December 2008 15:47:17 Praedor Atrebates wrote:
> > I don't understand this message.  My tor log (in tork) is full of
> > repetitive messages:
> >
> > 2008-12-03 15:42:38 WARN      (1 of 1) Failing because we have 1004
> connections
> > already.  Please raise your ulimit -n.
> >
> > Over and over (with variable numbers of connections around 1000.
>
> Forgot:  using tor-0.2.1.7 as a relay server.
>
> praedor

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