Subject Re: Odp: [firebird-support] FB server installation a nd concurrent users limits on Windows Server
Author Mark Rotteveel
On 6-11-2014 20:22, af_123xy@... [firebird-support] wrote:
> i am "new" to databases and i am "going to choose" Firebird.
> Supposing that i will have to interact with some MS server where are
> some already installed software, mail server and other softwares i were
> starting to ask if is there any limit about the number of concurrent
> Clients that could access simultaneously to the FB database.

Current windows versions of SuperServer and SuperClassic has a limit of
1024 concurrent connections, but that limit does not exist for Classic.
However if you need that many concurrent connections you might sooner
face different problems ;)

> Some peoples are suggesting me to do not install FB server on a domain
> controller becouse i will risk a serious perfomance issue.

Yes, an active directory install will disable some of the caching on the
disk it is installed on. So running a database on that disk will perform
worse than on a normal system.

And as Marcus mentioned, your active directory is pretty important it is
better not to use it for anything else as that reduces the chance of
problems and outages or security issues.

> Some Others are telling that is only a question of server,cache,page
> size ,etc
> i am getting confused becouse

That is because you are confusing general advice on performance with the
specifics of running Firebird on a server that also serves as an active
directory domain controller.

> i've got some post of the 2012 talking about FB that solved this issue
> but other that tell's that also Microsoft suggest to do not install
> MSSQL on an acvite domain

Based on your link below, you are confusing the specific problems of
running on an active directory server with a problem with the windows
filesystem cache on 64 bit windows. An issue that has been addressed in
Firebird 2.5.2.

> some more tells to do not install "ON" , other to do not install "FB AS
> acting ALSO like a domain controller" (does FB could act in that way?)

I have no idea what you mean with this sentence. I think you misread the
sentence "DO NOT set up the postgres database server to also act as
ACTIVE DIRECTORY or as a DOMAIN CONTROLLER." in your third link. It
means don't run active directory on the same server as postgresql. The
same advice applies to firebird or any other database server.

> all this becouse of a security functionality that Microsoft server apply
> on an DC
> my main doubt is :
> when i will have only 1 server on an already working network
> infrastructure of a customer and i will need to install my "small
> application" that will use FB in a c/s environment without having
> possibility to buy/install a second server , will i risk this
> PERFORMANCE ISSUE becouse of an incomatibility or i could solve it just
> "changing the configuration" of the MS server+ FB_db ?

When Active Directory detects the write cache is enabled on its disk, it
will force it to disabled, so you cannot change a configuration as
active directory will simply change it back. And as a domain controller
is pretty fundamental to the security, authentication and authorization
within a company it is also something that you don't want to mess up.

If you can avoid it at all, I'd suggest not installing Firebird on a
domain controller/active directory server. If you have no other choice,
then at least make sure you are running on a different *physical* disk
then the datastore of active directory (although that is still no
guarantee for good performance).

> this are some posts
> (FB)

Not related to active directory, but a filesystem cache issue on Windows
64 bit which has been fixed in 2.5.2.

> (MS) <http:
> //>
> (postgreSQL)
Mark Rotteveel