[Dovecot] [sfs: dovecot-auth file descriptor usage]

[Steven F Siirila]

On Wed, Jan 10, 2007 at 10:33:19PM +0300, Odhiambo WASHINGTON wrote:
> * On 10/01/07 10:43 -0600, Steven F Siirila wrote:
> | I am re-posting this message from last Friday, as I have seen no replies.
> | It is critical that we address this problem, since until then we cannot
> | put more than a few hundred users on our server.
> 
> I run a server with 8,000 accounts with dovecot rc15 all this time. A 
> few hundred is not a big number, since it's less than 1000.

That was my point; we only have the ability to put a few hundred on the
system, since any more than that causes us to start rejecting connections.

> | If Dovecot-auth TRULY needs to keep open a file descriptor for every single
> | login session, we will have to start looking at alternatives.
> 
> Are you threatening someone?

No, I was thinking more along the lines of looking at different ways to
solve the problem.  For example, compiling in 64-bit mode gets around the
Solaris limitation.  Or, going away from Solaris (not really an option).

> Seriously though, there must be something very broken in your OS, I 
> think. I run FreeBSD 5.5-STABLE on about 40 systems, all with dovecot 
> rc15 and each handling at least 100 accounts (bar for my big server with
> 8000+) and I don't hear complains...

Solaris 32 bit API prevents STDIO (FILE *) from referencing file descriptors
greater than 255.  That is because they value binary compatibility with
older applications.

> Why don't you start by switching OS? ;)

Not an option.  Thanks for sharing your experiences; we are very interested
in learning what our capacity limits might end up being BEFORE we reach them.
:)

> -Wash
> 
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