[Zope] is zope a solution?

[Jim Penny]

On Fri, Aug 31, 2001 at 08:39:29PM +0100, tonyl wrote:
> On Friday 31 Aug 2001 20:18 pm, Jim Penny wrote:
> 
> >
> > Yes, I am saying that the version I have crashes once or twice a week.
> > No, it does not make it at all unusable.  There are 86400 minutes in
> > a week. this makes it available  99.9976% of the time.  It is automatically
> > restarted after a minute without response goes by, so I do not have to
> > be here, etc.
> >
> 
> What planet are you using zope on Jim.? Your days last a real long time (or 
> my maths is awful) ;-)

Ah damn, that is seconds per week.  (Too used to thinking in seconds.)
Make that 99.86% availablity.

> 
> > Apache in my experience is better in terms of uptime.  But I have had it
> > crash, too.  I have had PostgreSQL crash.  I have has AS/400 services
> > crash.  Once you get beyond 3 9's of uptime, it starts to cost money.
> > I am running on clone hardware with no ECC, etc.  Prepare not to have
> > 99.999% uptime, and you can handle 99.99% uptime quite well.
> 
> For me, the issue is which of those minutes it's out of action. In my 
> situation, the application will be hammered at the start of the month, week 
> and morning (in that order). Most of the available minutes for statistical 
> purposes won't have much in the way of system activity. So 1 minute in peak 
> time is quite a high %age for the project. The equipment will probably be an 
> 8 way sun box with oracle.

Look, you are running on way more hardware with way better and way
more expensive gear than I am used to.  It sounds like you have
an actual budget.  If you can't get better uptime, I would be surprised.
I come from a different situation entirely.  In my situation, if it can't
be done with hand-me-down hardware and a bit of sweat equity, then it 
can't be done.

Also, all of that activity sounds like read activity.  Read activity,
in my experience, hardly ever triggers problems.  at least 90% of my
problems have been write related.

(And I still would be a bit surprised if your user base is upset 
by an occaisional minute of downtime.  The web has trained people
way too well that downtime is normal!)

> 
> I guess it has a user definable check-zope-is-up period? I'll soon change it 
> if it hasn't! (if I can).

It can be shortened, but beware (a bit).  You do not want the period so short
that zope cannot completely be reawakened.  That is, you do not want to
start hammering a restart process so hard that it starts taking down
processes before they can start responding.

Jim Penny

> 
> Thanks,
> Tony
>