David,

Thanks, I don't think the problem is here - this is single-thread
environent and my client app is sending little check-in SQL query
every minute.

--- In firebird-support@yahoogroups.com, David Johnson
<johnson_d@...> wrote:

>
> On Mon, 2006-03-27 at 14:01 +0000, Glebas wrote:
> > --- In firebird-support@yahoogroups.com, David Johnson
> > <johnson_d@> wrote:
> > >
> > > Sockets timeout on the server?
> > >
> > > If there is no activity, the OS will close the socket. An

open but

> > > unused socket is a potential security hole.
> >
> > Ok, and how to fix that? :)
>
> Make sure that, even when there is no application activity, you

issue

> regular keep-alive transactions on the connection. Say, once

every 15

> minutes. To keep from sending spurious transactions, reset the

timer

> every time you issue a genuine transaction.
>
> I am not sure if a simple {startTransaction ();commit();} would do

the

> trick, or if you would actually need to issue some sort of work -

say

> select the current timestamp or a generator value or something.
>
> In a multi-threaded app, where the connection runs in its own

thread,

> wake every connection thread up and have the thread mainline code

smart

> enough to recognize that when there is no pending transaction from

a

> user it still needs to run the keep-alive transaction.
>
> In a single threaded app, set up an OS or JVM level timer

(depending on

> your environment - Delphi TTimer is an OS timer) so whenever it

fires it

> invokes the dummy transaction on the connections. Set up a

semaphore to

> protect the connection so that only the timer or the application

may

> actually try to run a transaction at any time. Reset the timer

after

> every successful or failed request.
>