[debian-mysql] Bug#450535: Bug#450535: libmysqlclient16: Please version symbols differently in libmysqlclient_r and libmysqlclient

[Christian Hammers]

On Wed, 07 Nov 2007 23:23:03 +0100
Stefan Fritsch <sf at sfritsch.de> wrote:

> Package: libmysqlclient16
> Version: 5.1.22rc-1
> Severity: wishlist
> 
> Dear mysql maintainers,
> 
> there will be mysql support in libaprutil, which will use libmysqlclient_r.so.
> Together with php's mysql extension, this means that both libmysqlclient_r.so
> and libmysqlclient.so will be loaded into Apache. This is probably a very bad
> idea, since both libraries use the same symbols and symbol versions.

The *_r and the normal version only differ in that _r is "reentrant"/multithreading
ready, right?

> 
> A conversation on #debian-devel with seanius, vorlon, and peterS came to the
> conclusion that the best solution would be to have libmysqlclient_r and
> libmysqlclient use different symbol versions. To have only one mysql library
> transition until lenny release, this would need to be implemented in the first
> upload of 5.1 to unstable.

I would like to coordinate that with upstream so that shared binaries work across
distributions (also such compatibility is probably rarely needed).

> Other suggested solutions were
> 
> - link php-mysql to libmysqlclient_r

The problem would appear soon for other applications that happen to link 
a lot of shared libraries again, or? Do you know how libpostgres, libxml or
other libraries handle this case? Or if mod_auth_mysql starts using it.

> - make libmysqlclient symlink to libmysqlclient_r

> but these might cause unnecessary performance degradation. (Although I don't
> know whether this is really an issue).

Would that work? The performance degradation would indeed be neglible
as most time is usually spend in the server and not in fetching the result
data.


I will open a bug report at http://bugs.mysql.com to discuss this with
upstream this evening. Feel free to do so before if you have time.

bye,

-christian-