At 08:44 AM 16/02/2006, you wrote:

>Helen,
> downloaded and installed the Firebird 1.5.3 nptl version. In
>production environment after a couple of days the database engine hang
>and the only solution seems restarting the server.

1. Exactly what does "hang" mean in this context?
2. What do you see in the firebird.log?

>After this the
>problem disappear for about other 2 days, then you've to restart
>again.

>The applications that work on the database seems suddenly
>unable to attach to the database. The database will be unreachable up
>to the server restart.

3. What happens to clients that are already connected?

>This happens only on RedHat ES4 machines, on
>similar machines running RedHat 9 and Firebird 1.5.1 we never
>experienced such trouble.

4. Are you certain you were previously using Superserver 1.5.1 on RH
9, or could it have been Classic?

>The applications working on database
>performs very easy tasks, so it seems really a compatibility issue
>with the RedHat ES4 OS or the underlying (IBM 346 Server-Xeon single
>processor) hardware.

5. If it was an OS compatibility issue, we would surely know about
it by now. I'm reasonably sure, anyway, that Alex builds the
Superserver on FC 4. I can't comment on any traps with that
hardware, though it doesn't ring any bells.

6. However, there could be a compatibility issue for any clients
trying to connect with a mismatched client library.

Suspect a configuration issue, e.g. you previously configured
something in your old firebird.conf and now you are running with the
unmodified firebird.conf of the new installation? Or you have a
misconfiguration somewhere in the new network setup? Or your app
uses events and the engine's requests for random port assignment are
being denied by the firewall?

However, if you are sure that the system is configured to do all that
you ask of it, try posting your problem in firebird-devel, providing
as much detail as you can, including the log entries and a proper
description of what "hang" means in your context.

./heLen