--- In firebird-support@yahoogroups.com, "Nicholas Cain"
<mymailinglists@n...> wrote:

>
> --- In firebird-support@yahoogroups.com, "Ann W. Harrison"
> <aharrison@i...> wrote:
> > Nik wrote:
> > >
> > >
> > >
> > > I have an application that creates 50 threads, and then every 5
> > > seconds all the threads attach and insert some data into a
> firebird
> > > Super Server 1.5 database (this is currently using the

firebird

> C++
> > > api rather than things like ibpp etc).
> >
> > Ouch. In Firebird 1.5, connections are heavier-weight than they
> could
> > be. Could you leave the connections in place and just start &

stop

> > transactions? Transactions are much lighter weight. Each
> connection
> > has a separate copy of that part of the metadata that it uses.

If

> you
> > kept the connection you'd not only keep the metadata, you might
> also be
> > able to keep the prepared insert statement...
> > >
> > >
> > > Occasionally a thread will throw up;
> > >
> > > Unable to complete network request to host "127.0.0.1".
> > > -Failed to establish a connection.
> > > -Connection refused
> >
> > One possibility is that your Linux is configured (as many are by
> > default) to limit the number of simultaneous connections.
> >
> > Regards,
> >
> >
> > Ann
>
> I've found the linux connection limit in xinetd (thanks to Adam),
> although I'm not sure it has made much difference yet. However,
> preventing the repeated connections and leaving just transactions
> sounds a good idea. I'll have a go and see where it gets me...
>
> thanks,
> nik

Sorry I was in a bit of a rush last night Nik, so I didn't get to
answer properly. I agree totally with Ann's advice, 250 connections
consume a lot of system resources, only use that model if you have no
other choice. Unless you need Isolation between the inserts or you
want to make sure any failed insert doesn't prevent other inserts
from running, you can probably get away with just one transaction.
What sort of hardware have you thrown at this project? If you are
doing a lot of inserts, it will be faster to disable any indices
before the inserts and re-enable them afterwards.

Adam