Hi Michael,

Thanks for the information. Clearly LockSemCount = 500 is significantly higher
than the default value of 32 - how did you arrive at this value? I'd really
like to know what factors should be considered when changing this value - can
any of the Firebird developers explain the significance of this?

Tom

On Wed, 29 Jul 2009 20:59:16 Michael Weissenbacher wrote:
> Hi Tom!
> I have been running a heavily loaded Firebird Classic 2.0 on a (Gentoo)
> Linux Server for about 3 years without a hitch with the following settings:
> firebird.conf:
> LockSemCount = 500
>
> /etc/sysctl.conf:
> kernel.shmmax = 1073741824
> kernel.sem = 1024 32000 256 1024
>
> /etc/xinetd.d/firebird:
> service gds_db
> {
> disable = no
> flags = NODELAY KEEPALIVE IPV4
> socket_type = stream
> wait = no
> user = firebird
> server = /opt/firebird/bin/fb_inet_server
> cps = 0 0
> instances = 1000
> per_source = 300
> log_type = FILE /var/log/firebird/xinetd.firebird.log
> }
>
>
> I had some problems in the start with the Lock Manager, before increasing
> the default values. Another important thing are the "instances" and "cps"
> settings of xinetd, which may prevent new connections under certain
> circumstances.
>
> hth,
> Michael
>
> -------- Original-Nachricht --------
> Betreff: [firebird-support] LockSemCount
> Von: Tom Munro Glass <tom@...>
> An: firebird-support@yahoogroups.com
> Datum: 28.07.2009 06:35
>
> > Running FB classic 2.1.2.18118 on Mandriva 2009 with an unmodified
> > firebird.conf.
> >
> > I have had a corrupted database, and prior to this firebird.log contains
> > the "Fatal lock manager error: semaphores are exhausted" message. The
> > system would only have had one or two users connected at the time, so can
> > someone please tell me what operations cause a semaphore to be used? For
> > example is the number of semaphores used affected by the number of active
> > transactions, and does running nbackup use any semaphores?
> >
> > Also, does this message mean that FB has used all of semaphores as
> > determined by LockSemCount (default 32 I assume) or does it mean that
> > Linux has run out of semaphores?
> >
> > I'm trying to determine if I need to increase the value of LockSemCount,
> > and if so, what should I increase it to.
> >
> > Tom Munro Glass
> >
> >
> >