Re: [naviserver-devel] naviserver with connection thread queue

[Gustaf N. <ne...@wu...>]

Am 29.11.12 19:51, schrieb Gustaf Neumann:
> I will reduce the writersize further, but still a slow delivery can 
> even slow down the delivery of the headers, which happens still in the 
> connection thread. Most likely, i won't address this now.  however, i 
> will check the effects of fastpath cache, which was deactivated so far...
It turned out that the interactions between the various delivery methods 
of naviserver are more differentiated than i expected. As one can see 
from the graphics below, the content returning infrastructure of 
naviserver depends is very differentiated.

Look below at the call graph.
* The boxed nodes are the tcl commands, the pink nodes denote handling 
by the writer thread.
* Of course, the ns_writer command can be used on the application layer 
and tries always delivery via the writer thread.
* The implicit calls (e.g. ns_returnfile) go through FastReturn(), which 
calls Ns_ConnReturnOpenFd() only, when neither caching or mmap are 
activated. As soon one of these are activated, ns_return etc. will never 
use the writer thread.
* All of the error messages or redirects use the path via Ns_ConnWriteChars.
* Only content sent via Ns_ConnWriteVChars has the chance to get compressed.
* Similarly, range requests are not handled when the data is not sent 
ReturnOpen to the writer Queue.
* The nodes with the gray background are marked as deprecated
* The nodes with the grey font are not called at all
* The nodes with the blue font are in the driver, and not further analyzed.

To make it short:
* caching and mmap deactivate the implicit delivery via the writer
* the non-200 return messages are always delivered via the connection 
thread; reducing the writersize does not make any difference.
* there is quite some potential to simplify / orthogonalize the servers 
infrastructure.
* improving this structure has nothing to do with 
naviserver-connthreadqueue, and should happen at some time in the main tip.

-gustaf neumann