Forum OpenACS Development: Re: OpenACS Performance Tests
neophytos, i think, you meant tclthreads and not "tthread" (which sounds close to zoran's ttrace). The c-level code for background delivery is part of naviserver and aolserver 4.5 in the cvs head version. You find patches for aolserver 4.0 and plain 4.5 in the wiki.
xorb is very different from ttrace and is no replacement. ttrace can help to make threads thinner, at the cost of making introspection more complex/wrong. ttrace is not (at least was not) depending on any naviserver code, Zoran wrote it for aolserver. ttrace has XOTcl support and vice versa.
The primary argument in the discussion above: assume you have 10 connection threads configured and you want to server some larger files over some slower lines (600 MB files, delivery might take 2 minutes per request). If 10 people download these files via connection threads at the same time, the server won't be able to serve any requests for these 2 minutes, since tall connection threads are busy; incoming requests will be queued. When you have bgdelivery installed, the connection thread is only used for permission checking and file location on the disk (usually a few milliseconds). This leads to much better scalability.
about tclthreads: The package on TCL's file distribution area (on sf) is called thread-2.6.5 (not sure if that's what you mean). That package also includes ttrace, yes.
about ttrace: NaviServer has that integrated or makes use of it in order to provide tracing as an option. I haven't used that due to some problems that existed between that mechanism and XOTCL back when I tried (as soon as it was released). I remember sending you a message about that but I am not sure what's the current status.
about xorb: yes, I did not mean to imply that it is a replacement but it does serialize/deserialize code from a single thread and it also makes threads thinner, right? (just asking)
The c-level code for background delivery is part of naviserver and aolserver 4.5 in the cvs head version. You find patches for aolserver 4.0 and plain 4.5 in the wiki.If you use NaviServer, it's already there.