It turns off all advanced socket mechanics for accepting connections. That means it won't pre-fetch data. Because of how cobbled-together the WinSock network stack drivers (third parties, included) were, there are many things that break sendfile (disable sendfile) or socket reuse (disable advanced accept logic).
In other words, if you need reliability on some pretty crazy installations of Windows with lots of out-of-date drivers, your solution is the way to go. They are for performance, there is no reason to turn these on in low-traffic cases. On Wed, Jun 10, 2015 at 10:31 AM, Andy Wang <aw...@ptc.com> wrote: > I originally asked this on user@httpd and didn't get a response, so > thought I'd redirect to dev and see if anyone can explain why this would > occur if you have time. I have to admit, it's a curiosity to me, that I > just don't want to let go until I understand it and what research I've done > into AcceptEx doesn't seem to be giving me any more insight. > > --- original message --- > > We've come across numerous cases where apache httpd 2.4 (I'm using > 2.4.12 but I don't believe this is version specific) hang using the > default configuration options. > > There are two cases > 1) we have an InstallAnywhere installer that launches httpd during > install time to do some initial work. When the installanywhere > installer starts httpd.exe (it does it via cmd.exe) httpd does not > respond to requests. If you kill the installanywhere installer, then > all of the sudden httpd starts responding > 2) certain IE 11 client requests hang httpd 2.4. > > I've wireshark'ed #2 and at some point, an http GET gets an ACK and > nothing more. I've peeked a little bit at the process threads with > processexplorer (unfortunately i'm not a windows developer, so I'm not > entirely familiar with the low level windows stuff) and everyhting looks > like it's okay and simply waiting for requests. > > What I found after googling and testing is AcceptFilter http|https none > prevents both of those problems. I've not yet tried connect to see if > that works either. > > But what I'm really wondering about is, can anyone explain, especially > in #2, what it is about AcceptFilter http none that actually resolves > these types of issues? > > Thanks, > Andy > > > > >
