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From Luca Toscano <>
Subject Re: Async write completion broken in trunk?
Date Wed, 18 Jan 2017 13:25:46 GMT
2017-01-18 14:00 GMT+01:00 Jim Jagielski <>:

> > On Jan 18, 2017, at 7:50 AM, Graham Leggett <> wrote:
> >
> > On 17 Jan 2017, at 7:40 PM, Luca Toscano <> wrote:
> >
> >> Since this email thread seems important, is there any update from
> anybody working on it? It would be great to open a bugzilla task otherwise,
> to track everything and make sure that we don't forget about it :)
> >
> > I looked at this a while back - I found that pipelining support is
> causing the blocking.
> >
> > When we’re handling pipelined requests and we reach a limit, we block.
> What we should be doing instead is looping round back to WRITE_COMPLETION,
> waiting for permission to write again. This should be reasonably
> straightforward to fix, but my financial year end is the end of this month
> so can’t look at this till February.
> >
> > I suspect pipelining support has been suppressed in v2.4.x event MPM,
> and was at some point “fixed” on trunk, bringing this problem back.
> >
> Somewhat on-topic but also off-topic as well, but it does seem
> that event on trunk is getting much more fragile instead of more
> stable. It seems to be picking up some kruft which is making
> event on trunk a *worse* option than what's in 2.4, despite a deeper
> async alignment.
My 2c view on this is that mpm-event has been getting better during the
last months, but the nature of the changes, together with the fact that we
have not developed a good way to test regressions, causes long running
debugging tasks. In the case of the wake-ups, we are basically testing a
new big feature thanks to live traffic from Stefan Priebe (thanks again for
the help btw!), meanwhile it would be really great to have some sort of
test to fake traffic and spot problems (that would absolutely not
substitute the invaluable user feedback of course).


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