On Sun, 29 Jul 2012 10:07:18 +0200 Henri Beauchamp <sl...@free.fr> wrote:
> On Sun, 29 Jul 2012 05:23:15 +0200, Carlo Wood wrote: > > > On Fri, 27 Jul 2012 16:59:18 -0400 > > holydoughnuts <holydoughn...@gmail.com> wrote: > > > > The implementation that I wrote for Singularity (not yet in the > > the official release) is more on the side of "blazing fast" :p. > > The bottleneck is entirely server-side, but I've seen download > > speeds of 1 MB/s non-stop till all textures were there. > > With just a few tweakings to the texture fetcher (and in particular > a setting that permits up to 32 concurrent HTTP fetches), I get much > more than 1MB/s in the Cool VL Viewer... In fact, I'm more in the > 10MB/s+ range while rezzing in heavily textured areas and the rezzing > time is pretty low... This has been so for many months (well over > a year actually) already. I agree that that would be an advantage for the user; but it's not clear to me if it is allowed (or will be in the near future) to have 32 concurrent fetches. The rationale that it SHOULD be allowed is that the user will download those textures anyway; so, you might as well allow them to get it quickly, in a short time: this has no influence on the average number of open file descriptors on the server. I understand that LL is afraid that once viewers can keep sockets open (for reuse) that the servers run out of filedescriptors. Of course, this is all to true. Therefore I propose to set a limit on the maximum number of UNUSED filedescriptors. However, there should be no limit or a much higher limit, on the number of connections that are actually in use. The question is then: when is a filedescriptor "unused"? Well, I'd say that for the sake of re-use, it can be considered unused if there hasn't been a new request for it for -say- a second. It's probably best to define multiple stages, that is: * Allow a maximum of 32 connections. * Allow up to 32 connections that are unused for 1 second. * Allow up to 8 connections that are unused for 10 seconds. * Allow up to 2 connections that are unused for 1 minute. * Allow 1 connection to be unused for 20 minutes (or whenever one leaves a region and it can be determined that this server won't be needed or used anymore). Of course this means that upon teleport to a new region with many unknown textures, the viewer will make 32 new SSH connections, but that is MUCH less than one new connection PER TEXTURE, as we have now. Then all those connections are reused until all textures have been downloaded (a few seconds). Other strategies are possible, like NOT immediately creating a new connection as long as the maximum of 32 connections haven't been used up yet, but waiting with that until there's a queue of requests building up. Bottom line is, I'm afraid that Linden Lab is going to take the (too) simplistic route as they often have done in the past, and do something very silly like: * Allow a maximum of 2 connections, and allow to keep them open indefinitely. I hope you see the difference :p I argue that something like that makes no sense and would hurt the user because they'd have to wait unnecessary long before everything downloads. -- Carlo Wood <ca...@alinoe.com> _______________________________________________ Policies and (un)subscribe information available here: http://wiki.secondlife.com/wiki/OpenSource-Dev Please read the policies before posting to keep unmoderated posting privileges
