Re: Best way to retire old code for unsupported database versions

On 27/09/13 03:52, Greg Sabino Mullane wrote:
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>> what to do about having something around that you can refer people who
>> want to run 4.x (???!!!). Is a simple information tidbit "if you
>> want to use xxx, you use version x.y.z version of DBD::mysql" ?
>> What have others done about this issue?
>
> Yes, it is basically as simple as that. Some thoughts:
>
> * Make your abandonment of old versions in large chunks, don't simply
> phase out older versions over time. In other words, consolidate the
> pain into as few releases as possible. Ideally, one every 10 years. :)
>
> * Have a version or two with lots of warnings in the docs before
> making the change.
>
> * Make the change at a major version bump. Then you can tell people
> they need version x, rather than x.y.z
>
> * This is also a good time to break other things - such as requiring
> a newer version of DBI. Consolidate that pain!
>
> * Provide instructions in the docs about how to reach the old versions.
> Have the frozen version available somewhere other than CPAN too.
>
> * Expect people who have been living off of those #ifdefs for years to
> suddenly crawl out of the woodwork after you flip the switch and complain.
> Anticipate their complaints in your docs so you can simply point them there.
>
> (MySQL 4.x? I know places still running 3.x!)

Everything Greg said ++, plus:

* when you make the break try and ensure your RT queue is clear of at least bugs or you'll get people saying they can't upgrade to get a bug fix because you withdrew support for their mysql version.

* try and catch someone trying to build against old client libs and output a meaningful message rather than just have the compile fail - preferably do this in your Makefile.PL or Build script and with the correct exit status you'll get a NA on a smoker instead of a Fail.

* as well as DBI, think about what Perl version you require - especially wrt unicode support although I see the latest DBI is 5.8.1 already.

Martin