On Thu, 26 Aug 1999, Scott Hess wrote:
> Yan Zhang Chen <yzc@stripped> wrote:
> > On Thu, 26 Aug 1999, Scott Hess wrote:
> > > One problem with this - our experience with versions through 3.22.23 is
> that
> > > write-locks followed by table flushes can cause mysqld to die in certain
> > > circumstances. I haven't tested with 3.22.25, yet.
> >
> > I also discovered this problem (and I posted some details a few days
> > agao, but didn't get any feedback from this list). How did you cope
> > with this problem?
>
> We stopped doing it. Do to a misunderstanding, we were using the write lock
> to lock the table while we copied away the files on disk. We converted to a
> read lock, and now it works fine.
The mysqld crash problem seems to happen for either READ or WRITE lock;
I was using the READ lock when I was reporting this problem early.
> In other cases where we might have used a write lock and a flush, if a read
> lock can't be made to suffice, then we drop the database entirely.
> Fortunately, we haven't come up with anything that's required that for quite
> some time...
But I got the impression that a WRITE lock followed by a FLUSH is needed for
"isamchk -r" repair without shutting down mysqld. The option for shuting down
mysqld for database maintenance is out of the question for such heavy 24x7
applications like ours. (I hope I can work something out with the developers
(I'm signing for the extended login support); if not we'd have to replace
mysql with something like Oracle)
