Hi
First let me tell that I'm not Firebird expert, I can only share my
experience.
In one system I have desktop application based on IBObjects with
concurrent users around 80-90 and REST service (for mobile application)
based on ZEOS with around 10 concurrent connections. All is serverd by
Xeon 1245 with SSD drives. Works like charm
The second one is only desktop application also based on IBObjects with
concurrent users around 50. This is server by some shitty virtual
machine running Windows (don't ask why :-) ) but the performance is
acceptable.
From my point of view, if transaction processing is OK in application -
the hardware of the server might be the source of performance
degradation (less RAM, old HDD).
Once I did a test on the machine from first system. We have started 200
connections each one performing non indexed queries in the loop, and
than we started connection 201 from the application and started to work
and performing daily user's task. Actually there no noticable difference
between being only 1 user or one of 201.
FireDAC, in my opinion will not improve anything.
And finally I'd like to ask, what kind of benefit you get from COMMIT
RETAINING?
My $0.02
HTH
Marcin
------ Wiadomość oryginalna ------
Od: "Jonatan Knud Lauritsen jonatan.laurit...@yahoo.dk
[firebird-support]" <firebird-support@yahoogroups.com>
Do: "firebird-support@yahoogroups.com"
<firebird-support@yahoogroups.com>
Data: 19.02.2020 09:20:55
Temat: RE: [firebird-support] Scalability of connection numbers of
client-server solution with Firebird 3.0?
I am trying to reply to Scalability of connection numbers of
client-server solution with Firebird 3.0?
1. I am not receiving messages from the yahoo Firebird group (I don't
want that they are coming in my mail, if I can always read them on the
Web and in the the nice threaded format and with history), but I am not
receiving answers to my questions as well - so - I don't know to how to
respond them technically. I am not happy about mail lists really, forms
and github issue formas are far more better way of communication.
2. I can do and I am doing proper transaction management with
IBX/Firebird Zeos as well, no need for futher enhancements. Currentl y
my MON$ATTACHMENTS lists some 30 connections and my MON$TRANSACTIONS
lists some 20-25 transactions, no older than 20 minutes. I guess that
is OK. Generally I open/close transaction for each read and save
operation and when user inteacts with the form I am ussing COMMIT
RETAINING options with the final COMMIT in the case when the form is
being closed. I guess, that is right? That should be the proper balance
that avoids long-running transactions and that also avoids recreating
transactions for each minot save or read.
Of course, I can migrate to FireDAC, but I don't see it as silver
bullet for any improvement if the MON$ATTACHMENTS and MON$TRANSACTIONS
data are good with the old IBX/Zeos as well. I can not see how can I
improve it further?
3. And I have never understood (and I still not understand) what kind
of dat a caching can be there for the ERP/accounting/manufacturing
management systems? Either on the client side or on the server side.
Well - my application caches (in detached, memory only ClientDataSets)
some short, common classifiers like list of some document types, list
of account codes, list or warehouses or the user preferences (all of
which is load during the startup time of the application). But anything
beyond that can not be cached: the catalog of goods is enormous - more
than 20.000 - how can I cache it? Catalog of customer is still larger
(more than 100.000). The list of documents is growing and so on, so on.
I simply don't understand what miracles the FireDAC can do there? Will
it make some AI analytics to decide some chunks of commonly used/rarely
mutable data? I have great doubts about the possibility of such
analytics and reliability of it. Database can do some caching based on
the data access patterns, but not FireDAC.
OK, I can understand caching for some web pages, web shops, newspages,
but there is little that can be cached (automatically or manually) in
ERP applications with OLTP and dynamic reports.
Thx, J.
