Subject Network Problems
Author Lester Caine
Not quite sure where to post this, but it is basically a support problem

One of my sites is having problems with missing data in the database,
but I'm convinced that there is a bit more to it than just a rolled back

The site is actually two offices, with a 2Mb link between them ( used by
other programs as well ). Our system provides two machines at each site,
and is accessed by the web browsers from client machines ( IE - this is
a council site :( - Moz/Firefox would PROBABLY give us error messages
that would help ). The rest of the network is 100BaseT, but the main
server is linked to a 1G backbone. So plenty of capacity locally.

Firebird 1.5.2 is running on the server on one site, and is accessed by
Apache2.0.54/PHP5.0.4 on the same machine, and the server at the second
office. All the browsers access their local 'web server'. The second
machine at each site runs an IBObjects based package which manages the
rest of the hardware, ticket printers, displays, audio announcements
etc. It basically just buffers the server from the slow speed bits. The
main stumbling block is XP on all workstation/browser machines and W2003
server on the servers - these are council offices so we have no say on
that :(

We are actually seeing a couple of problems which it seems we can move
around depending on which machine has Firebird on ( at some point
replication of the database between the two site is on the cards ;) ).
Rather than using Events, the system has it's own messaging system, and
multicasts to all the machines. This *IS* now set up properly after some
months of trying to convince the site that it was disabled on the link
between the two offices.

The MAIN problem relates to the MasterHub program, which gives 'Dataset
is currently fetching' pop-up some of the time ( this is created by
IBObjects ) and causes the whole system to slow down. Move Firebird to
the same machine as MasterHub (the link workstation rather then the
server machine) - no problems - but we do not have the problem on any
other site. This morning, the server has been patched direct to the
workstation, via a 100BaseT hub, and this is linked to the inter site
link. So far NO 'Dataset is currently fetching' messages where as they
were starting within a few minutes with the 1G backbone link.

The second problem seemed to be related, but may be a separate problem.
The system manages 'tickets' for people in the offices, and updates the
status of the 'ticket' as they move round. Sometimes these tickets are
getting 'stuck'. In that when they are cleared down ( the caller has
left the office ) they still show in the 'serving' queue. This is all
going through the PHP route, but only PART of the transaction is not
completing. The 'ticket' record is flagged as '-1' (finished), the staff
record has its flag to the ticket id cleared, and the 'room' record has
its serving flag cleared. Until the second and third updates are
complete the staff member can not call a new ticket, but on some of the
tickets on the REMOTE site from firebird, the first update is not
happening. The last two days we ran with Firebird/Apache/PHP on the main
site workstation (XP rather than W2003) so things were slower than we
would like, and the incidence of stuck tickets rose at the remote site,
but there were no local stuck tickets - while there had been a small
number previously!

Currently the site has Firebird on W2003, via a 100BaseT link to the
local work station - which has Apache/PHP still there ( one step at a
time), and the remote site has Apache/PHP on their server. Everything
seems stable at the moment, but we will not know about stuck tickets for
a while. The stuck ticket problem DOES come up at other sites, so is not
just here, but we have never seen 'Dataset is currently fetching' on
other sites, and the fact that the stuck ticket problem changes by
moving Firebird ....

So any ideas where we go next - while we wait for the current results.

Lester Caine - G8HFL
L.S.Caine Electronic Services -
Model Engineers Digital Workshop -
Treasurer - Firebird Foundation Inc. -