[ic] mysql having problems reconnecting on catalog reconfig

[Mike Heins]

Quoting Peter (peter at pajamian.dhs.org):
> I'm having problems with IC 5.7 (latest GIT HEAD), perl 5.12.4 and
> mysql.  When a catalog reconfig is done none of the sql tables would
> load back up all giving errors like this in catalog.cfg:
> 
> table 'variants' failed: table variants connect failed -- unknown error.
> Driver 'mysql' installed?
> 
> I traced the problem down to DBI.pm and found that if I change line 372
> from:
> 
> $db = DBI->connect( @call ) unless $bad;
> 
> ...to:
> 
> $db = DBI->connect( @call );
> 
> ...then everything now works again.  It would seem that for some reason
> the ached connection goes bad, but it all comes back to life if I allow
> an attempt to go through to reconnect.
> 
> I then checked the git logs to find out the history behind that line of
> code and traced it back to this commit:
> 
> https://github.com/interchange/interchange/commit/17a12070#L0R372
> 
> I'm not sure I really understand what the problem was that was fixed
> back in 2001 by this commit, but perhaps someone (Mike?) could shed some
> light on it?  It seems to make sense to me to try to connect again if
> the connection goes bad, so why are we not doing that now?  Is there any
> other light that can be shed on this problem?

It's a part of the alternate DSN stuff, where you can fall back to a
different database server if one is down.

But the bigger question is -- why did your connect fail originally,
so that you have a connection marked as bad?

-- 
Mike Heins
Perusion -- Expert Interchange Consulting    http://www.perusion.com/
phone +1.765.328.4479  <mike at perusion.com>

The sun, with all those planets revolving around it and dependent on it,
can still ripen a bunch of grapes as if it had nothing else in the
universe to do. -- Galileo