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#! rnews 3722 bsd Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!newshost.dca.gov.au!news.mel.aone.net.au!inferno.mpx.com.au!news.unimelb.EDU.AU!munnari.OZ.AU!news.mel.connect.com.au!harbinger.cc.monash.edu.au!news.mira.net.au!Germany.EU.net!howland.reston.ans.net!newsfeed.internetmci.com!uunet!not-for-mail From: davidsen@tmr.com (bill davidsen) Newsgroups: comp.unix.bsd.freebsd.misc,news.admin.technical,news.software.nntp Subject: Re: Poor performance with INN and FreeBSD. Date: 25 Mar 1996 00:33:49 -0500 Organization: TMR Associates, Schenectady NY Lines: 56 Sender: zorch@ftp.UU.NET Approved: zorch@uunet.UU.NET Distribution: world Message-ID: <4ipb5c$24om@usenetw1.news.prodigy.com> References: <311F8C62.4BC4@pluto.njcc.com> <4go23v$8hp@fozzie.sun3.iaf.nl> <DoJ1Js.H2t@unixhub.SLAC.Stanford.EDU> NNTP-Posting-Host: ftp.uu.net Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:16193 news.admin.technical:1367 news.software.nntp:21106 In article <DoJ1Js.H2t@unixhub.SLAC.Stanford.EDU>, Karl L. Swartz <kls@MAILBOX.SLAC.Stanford.EDU> wrote: | Frankly, I was pretty skeptical of the idea of having an NFS-based | /var/spool/news for my news server, figuring the access over the network | would be sure death. The appeal of having an enormous filesystem was | sufficiently tempting for me to at least give it a try, and I set up some | tests to compare a local disk with a model 1400 "toaster." The tests | consisted of a mixture of unbatching a bunch of news and deleting selected | files in random order, with other activity running "off the clock." | Unbatching was two to three times faster using than toaster than a local | disk, while the deletes were nearly an order of magnitude faster. Why are you worried about batch and unbatch, or feed times? Are you really running a news server with enough news to be a problem and few enough readers that they are NOT the problem? | Hopefully, I'll have a paper with all the details at LISA this year. ??? | | >Of course, I was thinking more along the lines of a log filesystem with the | >overviews stored in a separate SQL-oriented database, indexed by message-id, | >starting sector, and group:article#. | | I talked with Margo Seltzer a bit about news after one of her talks on the | BSD 4.4 log-structured filesystem and she thought news would be an excellent | application for LFS. I'd like to give it a try, but so far the code is still | supposed to be pretty buggy and I haven't had the time to fiddle with it. | I've never given the NOV part of it much thought since that's never seemed to | be the bottleneck, though maybe integrating it to handle the directory | portion of the FS would be interesting. Having run on a log filesystem (JFS on AIX), I can tell you that the log file is the bottleneck. To get performance up, first I put the logfile on a dedicated disk (cut expire time by 3), and then on a dedicated solid state disk (cut expire time by 3 again). Increases in storage of articles were noted, but the big winner was expire. | Separate filesystems also mean you have to invest more time in system | management, looking not just at how much space you expect to need overall, | but at which pockets you think you'll need it in. One of the attractions to | the "toaster" is that you just throw more disk at it when necessary, without | worrying about where exactly it should go. With disks being cheap and | reduction in staffing being plentiful, that's very attractive. Yes, but adding disk on striped filesystems is not generally easy, and the performance hit by not striping, at least for readers, is just not acceptable. -- -bill davidsen (davidsen@tmr.com) "As a software development model, Anarchy does not scale well." -Dave Welch