Re: backup transaction with io-thread core dumps

[Dietmar Maurer]

> On March 25, 2020 1:39 PM Sergio Lopez <address@hidden> wrote:
> 
>  
> On Wed, Mar 25, 2020 at 01:29:48PM +0100, Dietmar Maurer wrote:
> > > As expected, if both BDS are running on the same IOThread (and thus,
> > > the same AioContext), the problem is not reproducible.
> > >
> > > In a general sense, we could say that completion modes other than
> > > "individual" are not supported for a transaction that may access
> > > different AioContexts. I don't see a safe an easy way to fix this. We
> > > could opt for simply detect and forbid such completion modes when the
> > > BDS's are assigned to different AioContexts. Perhaps Kevin (in CC) has
> > > a better idea.
> >
> > So the solution is to disable backups when using io-threads?
> >
> 
> I meant forbidding transactions with completion-mode == grouped. It
> would be still possible running transactions (and thus, backups) with
> completion-mode == individual, which is the default.

As mentioned earlier, even a totally simple/normal backup job fails when
using io-threads and the VM is under load. It results in a total
VM freeze!