Subject RE: [firebird-support] Re: Firebird Restarting part 2
Author Alan McDonald
> > if I saw this error in my logs I would be doing a backup/restore
> immediately
> > to ensure no corruption.
> This DB contains 1 table with 38 records.
> They are all there.
> There is never add'ed any records.
> There is never deleted any records.
> A backup - restore can be performed tonigth, but wasn't last night.
> > Was the db moved by backup, then restore on the new server? or file
> copied?
> It was copied from the old server to the new one.
> No users where connected at the time.
> The FB was stopped prior to copying.

copied from 64 bit to a 32 bit OS? Is that a good idea?

> > Is E a physical HD? hope it's not a logical one - I don't know what
> "SX80
> > storage" means if it's not a real HD.
> Its a RAID 10 storage. I think its called a SAN array.
> > How may simultaneous users do you have?
> between 50 and 200. Give or take a few.
> > I always had in the back of my mind that 100 would be tops - after
> that I
> > use a 3rd tier.
> This I don't understand.

oh dear. I think 100 has for a long time been a magic maximum of
simultaneous connections to FB before you are encouraged to provide a middle
layer to your connections to allow connection pooling. A middle tier will
make, say, 50 live connectiosn to the db server and your 200 clients will
connect to the middle tier. This ensures that the FB server load is managed
more appropriately.
See RemObjects as an example which is popularly used. I haven't tried it
myself, but I know that such a move (to middle tier connections) requires a
fair amount of architectural change in the way you think of your application
acquiring/using data served and posted back to the server.
I know there are some people on this list who have high numbers of
simultaneous user connections - maybe much more than 100. I have always
resorted, though, to providing more servers and I replicate data between the
servers. I spread the load around by ensuring users are connected to
different servers. The data is never more than about 5 minutes out of sync.
But some architectures won't tolerate this. I'm luck my setups have always
been able to do this. If I were scaling to 200+ users and I were forced to
use one server only, I would be using a middle tier like RemObjects.


> Michael
> > Alan