Marco Colombo <marco@esi.it>:
> On Mon, 20 Mar 2000, Horst von Brand wrote:
>
> > Jesse Pollard <pollard@tomcat.admin.navo.hpc.mil> said:
> >
> > [...]
> >
> > > Without overcommit:
> > > You can support 100 simultaneous connections, with full saturation of
> > > each server, with no failures.
> > >
> > > Result: happy customers, happy management, maybe even a raise.
> >
> > Management nagging about supporting more pages, worried by waste of several
> > Gb of disk that has never, ever been touched. System is sluggish, needs
> > constant tweaking of "resource allocation quotas" as applications crash,
> > even there are resources available. Seriously consider firing inept
> > sysadmin.
>
> Then, the new sysadm turns overcommiting on, and suddenly you realize
> that you can support 300 simultaneous connections, with REAL full saturation
> of each server, with no failure. 100% agreed.
And the system crashes just after a flood of DoS connections hit, corrupting the
accounting database, and 3 days of downtime rebuilding the accounting....
And hoping nobody stole the credit card file while the system could not perform
auditing because it got aborted...
> Either the system is under control, or it's not. A perfectly tuned system
> never goes OOM or OOS. A badly configured system misperforms no matter of
> overcommitting being on or off.
YUP. absolutely. Although "perfectly tuned" assumes "perfect users" too.
-------------------------------------------------------------------------
Jesse I Pollard, II
Email: pollard@navo.hpc.mil
Any opinions expressed are solely my own.
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This archive was generated by hypermail 2b29 : Thu Mar 23 2000 - 21:00:34 EST