Lennert Buytenhek wrote:
On Mon, Feb 21, 2005 at 06:17:16PM +0100, Christian Schmid wrote:
Outgoing data. I am using sendfile() to send the file on a non-blocking
socket but the call blocks for 100 ms per socket if I get over 3000
sockets. Thats causing the massive slowdown in sum. I first thought its a
disk-issue but I tried with pure-cache data as well and it still blocks.
O_NONBLOCK send() is really nonblocking, but O_NONBLOCK sendfile()
really isn't, as it still does the disk read (if any) synchronously.
How are you making sure that you're sending "pure-cache data"?
Because thats the first I excluded. I changed the program by replacing
sendfile with a caching-routine plus syswrite. And it was really
interesting that the syswrite was the one which needs most of the
real-time, not the caching-routine. syswrite blocked 100 ms per socket.
Is your application written in C or perl?
Perl. But this is not the source because as stated in another mail, I tried with 6 processes when it
slows down at 500 connections each and with 2 processes where it only starts to slowdown at 2000