[mysql-dde] Re: Clocks Synchronization

  • From: "Peter B. Volk" <PeterB.Volk@xxxxxxx>
  • To: <mysql-dde@xxxxxxxxxxxxx>
  • Date: Mon, 12 Dec 2005 20:25:11 +0100

Well I remember that that was a critical issue in one of the MySql version.
My suggestion would be to evaluate the NOW() function in the Master node and
then distribute the value to the other servers. But the problem would be
that the other servers would have a different internal timestamp. I think a
nother chapter in the optimizationsbook should be a chapter on
Timefunctions. I think it should be advised that the DBAs have to sync the
clocs themselfse among the servers. Since I don't think that a Clock sync
should be part of the databases functions.

Peter
----- Original Message ----- 
From: "Fabricio Mota" <fabricio.oliveira@xxxxxxxxxxxxxxxx>
To: "dde" <mysql-dde@xxxxxxxxxxxxx>
Sent: Monday, December 12, 2005 5:54 PM
Subject: [mysql-dde] Re: Clocks Synchronization


> Hey, man!
>
> Another problem (I'm noting all of them) hahahaha
>
> If we don't sync the clocks (and I guess it's better don't sync them),
what
> about the funcion Now() ???
>
> And if the clocks being different, the user uses the time to comparate
> critical values order?
>
>
>
> ----- Original Message ----- 
> From: "Peter B. Volk" <PeterB.Volk@xxxxxxx>
> To: "Fabricio Mota" <fabricio.oliveira@xxxxxxxxxxxxxxxx>
> Sent: Monday, December 12, 2005 3:42 PM
> Subject: Re: [mysql-dde] Re: Clocks Synchronization
>
>
> >
> > ----- Original Message ----- 
> > From: "Fabricio Mota" <fabricio.oliveira@xxxxxxxxxxxxxxxx>
> > To: <mysql-dde@xxxxxxxxxxxxx>
> > Sent: Monday, December 12, 2005 4:48 PM
> > Subject: [mysql-dde] Re: Clocks Synchronization
> >
> >
> >> Yes, I do! send me please.
> >>
> >>
> >> ----- Original Message ----- 
> >> From: "Peter B. Volk" <peter.benjamin.volk@xxxxxxxxxxxxxxxxx>
> >> To: <mysql-dde@xxxxxxxxxxxxx>
> >> Sent: Monday, December 12, 2005 12:45 PM
> >> Subject: [mysql-dde] Re: Clocks Synchronization
> >>
> >>
> >> > Well I know rather a lot about it since we hade about 4 lectures
about
> > it.
> >> > The percision is as high as good you clock hadware is. The porblem
with
> >> > cloc
> >> > synch is that you have a drift rate of the clock plus network
overhead.
> >> > now
> >> > these numbers are only detectable with multible hardwareclocks. If
you
> >> > like
> >> > I can send you several ppt slides that have to do with clock synch.
> >> >
> >> > In terms of DDE I'd like to avoid any type of clock synch because
this
> >> > would
> >> > make averything a lot harder.
> >> >
> >> > Peter
> >> >
> >> >
> >> > ----- Original Message ----- 
> >> > From: "Fabricio Mota" <fabricio.oliveira@xxxxxxxxxxxxxxxx>
> >> > To: "dde" <mysql-dde@xxxxxxxxxxxxx>
> >> > Sent: Monday, December 12, 2005 2:43 PM
> >> > Subject: [mysql-dde] Clocks Synchronization
> >> >
> >> >
> >> >> Hey man,
> >> >> What do you know about clocks sync in Distributed Systems? What kind
> >> >> of
> >> > precision is possible to reach among machines?
> >> >>
> >> >> Fabricio Mota
> >> >> Analista de Sistemas
> >> >> FCPC - Divisão de Planejamento do Cadastro Comercial
> >> >> MySql-DDE discussion list
> >> >> www.freelists.org/
> >> >>
> >> >
> >> > MySql-DDE discussion list
> >> > www.freelists.org/
> >> >
> >> >
> >>
> >> MySql-DDE discussion list
> >> www.freelists.org/
> >>
> >
>
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