Looking for Feedback: Update mysql from 5.1 to 5.5

[Clint Byrum]

On Tue, 2011-02-08 at 14:22 -0500, Chuck Short wrote:
> Hi,
> 
> During the Ubuntu Server Team meeting I brought up the agenda item of 
> upgrading mysql 5.1 in main to mysql 5.5. There are several reasons to 
> do this:
> 
> * Its faster compared to mysql 5.1 (although I dont have any benchmarks)
> * There are more bug fixes for mysql 5.5.
> * Amazon is using it on the cloud images.
> * Packages are nearly ready to be uploaded.
> * Easier to maintain going forward.
> 

As excited as I am to get to 5.5 on natty (I have done most of the
initial packaging work to handle the build conversion from automake to
cmake), there seems to be at least one major gotchya in 5.5.8:

http://bugs.mysql.com/59078

They've marked it as "not a bug" .. but its very clear to me that
they've broken ABI compatibility without bumping SONAME. They're even
telling people that this non-bug requires users to re-compile everything
against 5.5 to get things to work.

They've also made libmysqlclient thread safe, eliminating the need for
the separate libmysqlclient_r. The way they've implemented that is also
broken:

lrwxrwxrwx 1 clint clint      24 Feb  8 18:38 libmysqlclient.so.16 -> libmysqlclient.so.16.0.0
-rw-r--r-- 1 clint clint 3414824 Feb  8 18:38 libmysqlclient.so.16.0.0
lrwxrwxrwx 1 clint clint      17 Feb  8 18:38 libmysqlclient_r.so.16 -> libmysqlclient.so
lrwxrwxrwx 1 clint clint      17 Feb  8 18:38 libmysqlclient_r.so.16.0.0 -> libmysqlclient.so

So it seems that they've still got some work to do to stabilize the
client libraries.

Seeing as the number of libraries that build-depend on
libmysqlclient-dev is quite high, I'd say the client libraries *must* be
of good quality.

That said, as long as we're ok with having 5.1 and 5.5 in main, the
libraries from 5.1 work *perfectly fine* to access a 5.5 server, so we
can just hold the client libraries back until they figure that mess out.