Date: Thu, 7 Feb 2008 13:16:19 +0300 From: Gleb Smirnoff <glebius@FreeBSD.org> To: Louis Mamakos <louie@transsys.com> Cc: cvs-src@FreeBSD.org, Alexander Motin <mav@FreeBSD.org>, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/netgraph/netflow ng_netflow.c Message-ID: <20080207101619.GH14339@FreeBSD.org> In-Reply-To: <F97B091A-A8D5-46F6-AB5D-6E1F915E53BD@transsys.com> References: <200801271501.m0RF1Hki089075@repoman.freebsd.org> <20080202201153.GL14339@FreeBSD.org> <47A4E122.8080901@FreeBSD.org> <C0C34BEB-3EB8-4552-B0BD-CE481311C77A@transsys.com> <20080205141739.GX14339@FreeBSD.org> <F97B091A-A8D5-46F6-AB5D-6E1F915E53BD@transsys.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Feb 06, 2008 at 10:59:32PM -0500, Louis Mamakos wrote: L> I suppose the problem is that I had no expectation that a kernel module, L> would L> consume unbounded amounts of kernel resources. It is bounded. L> I certainly didn't expect L> that L> it would have a need to store "a lot of data" given that there are L> documented L> parameters on how the in-kernel state should be expired. That this L> expiration L> doesn't occur is a significant difference that would I would have expected L> as L> reasonable behavior. This is behavior of not yet configured node. Imagine yourself adding a new log destination to syslog.conf(5), but forgetting about newsyslog.conf(5). Are you going to file a PR "FreeBSD wastes all my disk space"? No. Same situation here - you have configured the flow of incoming data, but you haven't configured the destination of the outgoing data. L> You start with the presumption that the data being collected is so precious L> that L> it cannot be dropped under any circumstances. That's probably a faulty L> premise to begin with, given that most of the netflow export happens on an L> unreliable UDP transport. Well, the ng_netflow(4) node has nothing to do with UDP. You can put any alternative transport on the "export" hook. L> > I agree that the behavior should be documented in manual page and using L> > ng_hole(4) for your case should be advised. If you send me a manual page L> > patch, L> > I can commit it. L> L> Driving the kernel into resource exhaustion for no really good reason L> doesn't L> seem like the right default behavior. I really think that the netflow L> module should default into a safe mode of operation rather than unexpected L> consumption of a limited resource. See above. -- Totus tuus, Glebius. GLEBIUS-RIPN GLEB-RIPE
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20080207101619.GH14339>