Greetingz!
Please note that in order to change
tcp_max_syn_backlog to a larger value, you might also have to change TCP_SYNQ_HSIZE defined in tcp.h (which would require a kernel recompile). For more info on
tcp_max_syn_backlog and other TCP variables, check
this link out.
Note that although the document covers the 2.4.x Linux Kernels, I've double checked the article for accuracy.
On my CentOS5.x system, I found TCP_SYNQ_HSIZE here;
Code:
/usr/src/kernels/2.6.18-194.8.1.el5-x86_64/include/net/tcp.h
#define TCP_SYNQ_HSIZE 512 /* Size of SYNACK hash table */
We also have a thread
here in LQ that covers RHEL-based kernel compiling (CentOS is based on RHEL).