[Mailman-Developers] Problem with MM after power outage

[Barry Warsaw]

On Mon, 2003-09-15 at 14:50, Peter C. Norton wrote:
> On Fri, Sep 12, 2003 at 05:56:00PM -0400, Barry Warsaw wrote:
> > On Fri, 2003-09-12 at 17:40, Harald Meland wrote:
> > > Hence, I think it makes more sense to have the default be "do
> > > fsync(2)", and let any performance-conscious site decide whether it
> > > wants to explicitly value performance over safety.
> > 
> > Except that when I did some very simple tests, I saw a 97% hit in
> > performance with fsync turned on.  This on a RH9, ext3 Linux box of the
> > Dell Optiplex variety.  That makes me very nervous to add in a patch
> > release that won't have any beta testing.  I've also never seen the bug
> > on python.org, which may or may not be representative of the world at
> > large.
> 
> Wow.  97%?  That's way too high.  I'd expect about 50% at worst - for
> the extra sync to disk when it enters mailman's queue and one more to
> flush the message when its made it though the outbound queue to the
> MTA.  This is just a question, because I still don't know much about
> the mm 2.1 internals, but is there a chance you're sync()'ing more
> often then you need?

It's possible -- I don't have my test script any more.  I just added a
flush before closing the config.pck file and I think that will help much
more than the sync.  IIUC, there's really only a narrow window of
opportunity for corruption that sync will solve, and if you're worried
about that, you really should be on a UPS and possibly a sync'ing file
system.

-Barry

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