Gentoo Archives: gentoo-admin

From: Damon Conway <kabau@g.o>
To: admin@g.o
Subject: Re: [Gentoo-admin] Rsync minimum connection limits
Date: Sun, 18 Aug 2002 20:08:44
In Reply to: [Gentoo-admin] Rsync minimum connection limits by Colin Morey
On Mon, Aug 19, 2002 at 12:22:38AM +0100, Colin Morey wrote:
> Do we have a defined number of minimum connections a server should > allow? or are we basing on an had hoc basis, based upon transit and > availability as well?
That is an excellent question, and one I've yet to find a good answer for. It is my opinion that we cannot afford to be too picky when someone offers their services to us, but it also doesn't help to have servers out there that can't perform. Unfortunatly, I've been too busy with life to give this matter much thought. The way I see it, we have three basic requirements for rsync mirrors. 1. Enough available bandwidth to serve a substantial amount of data. 2. Accurate and timely data. 3. Sufficient number of simultaneous logins to allow enough people to actually use the mirror. I would suggest that the mirror have at least a T1 of available bandwidth. It doesn't have to dedicate the entire T1 to rsync mirroring, but if all they have is ISDN, DSL, or cable, then they aren't going to be pleased with rsync using all of their bandwidth. I would suggest a minimum 128kb/s of available bandwidth for rsync bandwidth on a mirror. This number would be better at 256kb/s, but 128kb/s should be usable. Some method needs to be developed for making sure that mirrors are updated in a timely fashion, and have accurate copies of the master. There have been several reports of out-of-date and bad data on mirrors. Right now, we have people updating their mirror every 30 minutes on the 0 and 30. This will quickly become inadequate if we continue to grow our number of mirrors. Keeping an infrastructure like this healthy as it grows will probably be the biggest task this admin team will face. I have lots of ideas on this, but they can wait until we get some basic parameters down for mirrors. Right now, it should be sufficient to develop an automated system that checks for inaccurate and out of sync mirrors. The third item seems to be the big point everyone is interested in, and in my opinion the least of our worries. However, I'm tired of hearing people whine about it so I've given it some thought. This ties into item one since the more people you have using a server, the more bandwidth you need. I think we should have ratios of bandwidth to max concurrent users. Maybe 5 users for every 128kb/s of available bandwidth. Basically, to determine these numbers we need to determine the average user's rsync transfer, and come up with an average sustained data rate for an rsync transfer. Now, these are just my opinions. What do y'all think? Damon/kabau


Subject Author
Re: [Gentoo-admin] Rsync minimum connection limits Damon Conway <kabau@g.o>