On Thu, Nov 06, 2003 at 06:08:28PM -0800, jw schultz wrote: > I'm getting more and more convinced that --bwlimit should > never have gotten into rsync. Bandwidth management belongs > at the system level or let it be done with a common > networking utility instead of at the individual utilities.
There seems to be some strange idea floating around that i am suggesting that --bwlimit should be removed. Balderdash! Once a feature gets in it stays in unless it is completely broken such that no one uses it. Even broken features don't get removed without a super-majority and a major version number bump. This is why we have to be extremely careful about allowing new features into the mainline tree. > Why don't you see about getting it added to openssh. That > way it would be usable for more than just rsync. If rsync didn't have --bwlimit i would be pushing people to do it externally to rsync. To me it seems the perfect thing to add to ssh and i am sure there are utilities that can do it for pipes and for network ports. My point is that it belongs in the infrastructure not the application or if done in the application should be done using a plugin. But since rsync already has the feature it will stay. > If it is going to be changed it should be completely redone. > Use nanosleep() not the deprecated usleep() nor select() and > scale the block size according to the size of bwlimit. > > Special case hacks of --bwlimit get my no vote. And there you have my main point. A hack that causes regressions like the one proposed is bad. A fix that reworks the code and makes it more generally useful by eliminating existing bugs and limitations is good. The current version of --bwlimit is bursty on lower limits causing bandwidth overflow then dead time; and has a maximum throughput dependant on the system clock (4Mbps at 100HZ). A properly functional version would fix those problems and would also incorporate buffering to improve throughput (see archives). PS. With regards to the proposed patch I suspect that a write size of 1368 would produce better network utilisation than 1024. -- To unsubscribe or change options: http://lists.samba.org/mailman/listinfo/rsync Before posting, read: http://www.catb.org/~esr/faqs/smart-questions.html
