5.0 client + 2.5 server

[Tomasz Tyrakowski]

Hi

I'm preparing to migrate away from 2.5 to 5.0 (multiple servers). Is it
safe to use (during the transition phase) the client libraries from 5.0
to connect desktop clients (via TCP/IP) to the 2.5 server (so that I
don't have to keep track which version of client libraries to deploy
where)? I encountered no problems while testing (so far), but preferred
to ask just in case. Anything to pay special attention to in such setup?
It's supposed to be only temporary, the final setup will be 5.0 on both
sides of course.

best regards
Tomasz

[Mark Rotteveel]

A Firebird 5.0 client is able to connect to a Firebird 2.5 server over
TCP/IP just fine. The wire protocol is versioned, and the 5.0 client
still supports protocol version 12 of Firebird 2.5.

The reverse (2.5 client to 5.0 server) is not necessarily the case,
especially with newer data types, and possibly - can't recall for sure -
with longer metadata names.

Mark
--
Mark Rotteveel

[Tomasz Tyrakowski]

On 19.04.2024 at 14:29, 'Mark Rotteveel' via firebird-support wrote:
> A Firebird 5.0 client is able to connect to a Firebird 2.5 server over
> TCP/IP just fine. The wire protocol is versioned, and the 5.0 client
> still supports protocol version 12 of Firebird 2.5.

Thank you for the confirmation.

> The reverse (2.5 client to 5.0 server) is not necessarily the case,
> especially with newer data types, and possibly - can't recall for sure -
> with longer metadata names.

In the transition phase I'll definitely set data type compatibility to
2.5 in 5.0 server configs, so probably data types wouldn't be an issue.
The long object names also shouldn't be a problem (while there are still
2.5 servers running at some sites, we can't use long names - we prefer
to have unified metadata across all databases).
However, I'm not going to go down that path anyway, 'cause I'd like to
finally have 5.0 both server- and client-side, so I'm definitely more
interested in deploying 5.0 client libraries with the next desktop app
upgrade, and then migrate the servers one by one (which will take some
time and will result in some sites still running 2.5, and some 5.0 -
with the 5.0 ratio increasing, hopefully one day to achieve 100% :) ).
Thanks again for a prompt response.

cheers
Tomasz