| Subject: (6.12) How do I set up a delayed IHAVE/SENDME over NNTP? |
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Christophe Wolfhugel <Christophe.Wolfhugel@grasp.insa-lyon.fr> writes: Having some of your NNTP newsfeeds delayed by a fixed amount of time is a good way to reduce your bandwidth requirements, or a good way to set up a backup-feed. By including a Wt flag in your newsfeeds file, INN will insert timestamp entries in that batchfile, channels, or exploders. This timestamp can be used to implement delayed ihave/sendme processing. INN's senders (like innxmit) do not use that data yet. However, NNTPLINK does support this delayed IHAVE/SENDME mechanism since release 3.3 (NNTPLINK can be found on ftp://shape.mps.ohio-state.edu/pub/nntplink/nntplink.tar.gz). HOW TO DO IT: The syntax that you would use in your newsfeeds file would be: site:*:Tf,Wtmn:and run this command now and then: nntplink -i batchfile -y 300 -b site news.site.frThe delayed IHAVE/SENDME is expected to allow bandwidth savings in situations where all sites use nntplink in following topology: Your site -- 64k -----------+----------- Site 1 | | | 2mb | | +------------ Site 2Site 1 and 2 are in the same metropolitan area, you feed them both. With the standard nntplink layout, you generally send all articles twice, which is a waste even if you're at 2 Meg/s link and even if Site 1 and 2 do nntplinks, you're faster. The delayed link would be used between your site and Site 2. A 2 or 3 minute delay allows Site 1 to feed Site 2 before you, and in case of a Site 1 outage the backup starts nearly immediately. Reasonable delays are still kept as You -> 1 -> 2 should take less than one minute (or just 300 ms disk to disk if using nntplink -i ? :)). Experiences seem to show that a 2 to 3 minutes delay is a reasonable choice. Chris ------------------------------ [Last Changed: $Date: 1997/07/01 01:25:41 $ $Revision: 2.21 $] [Copyright: 1997 Heiko Rupp, portions by Tom Limoncelli, Rich Salz, et al.] |