Messages in this thread | | | Date | Wed, 15 Mar 2000 15:16:49 +0000 (GMT) | From | James Sutherland <> | Subject | Re: Some questions about linux kernel. |
| |
On Tue, 14 Mar 2000, Peter T. Breuer wrote:
> "A month of sundays ago Jason Gunthorpe wrote:" > > On Mon, 13 Mar 2000, James Sutherland wrote: > > > I want to emphasise this point: the OOM handler should **NEVER** be > > > invoked. If it is ever needed, there is something BADLY wrong with the > > > system - either we do something drastic (process slaughtering) or the > > > machine goes down completely. Worrying about which user processes are > > > > Just as someone who has been bitten by this, I agree with James. The > > number one priority is keeping the machine up - I don't care what you > > kill, just keep it running and preferably allow remote logins still... > > The problem is that it is the process killer that is killing the > system, nothing else. > > The usual scenarios here are: > > a) httpd goes nuts because of some random bug and spawns 250 copies > of itself and sits there humming. System begins to drag, sendmail > begins to have trouble, connects start timing out leading to more > sendmail reconnects and more sendmail processes. Procmail can't > launch to do local deliver modes and sendmail throttling kicks > in producing bursts of process creation, followed by procmail > waiting forever on a single lock. Meanwhile nfs exports become > clogged and the system begins to labour .... > > Cure: knock out httpd.
Yes.
> b) Someone leaves netscape running unattached. It tears up the network > connection somehow. Networking begins to die, daemons like nfsd > and named start to loop internally, memory drops, error messages > spawned and can't be sent. Process killer kicks in. Kills cron, > nfsd or mountd, inetd or init (in order of probability, as far as > I can make out). System dead, won't reboot or take logins. > > Cure: stop the process killer. Things will just about work > forever in this state. Not well, but forever.
No. Process killer kills Netscape (and anything else which has exploded as a result). Again, correct remedy. nfsd etc. will only be killed if they have already malfunctioned - I would rather have no nfsd running than a broken one, since a watchdog script can much more easily restart a fresh nfsd if the old one has gone.
James.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |