System can't take more than 5k req /sec

[Jason Price]

(And Jorge: iptables isn't in play at all.  lsmod | grep iptables
shows nothing.)

On Mon, Apr 28, 2014 at 4:37 PM,  <lnsano at bol.com.br> wrote:
> Could you print the output for?
> $ ss -s
> $ sudo sysctl -a|egrep
> "ip_local_port_range|tcp_max_tw_buckets|backlog|somaxconn"

[root at XXXXXXXXX ~]# ss -s
Total: 853 (kernel 6127)
TCP:   695 (estab 292, closed 94, orphaned 0, synrecv 0, timewait 94/0), ports 0

Transport Total     IP        IPv6
*         6127      -         -
RAW       0         0         0
UDP       8         5         3
TCP       601       598       3
INET      609       603       6
FRAG      0         0         0

[root at XXXXXXXXX ~]# sysctl -a|egrep
"ip_local_port_range|tcp_max_tw_buckets|backlog|somaxconn"
net.core.netdev_max_backlog = 5000
net.core.somaxconn = 512
net.ipv4.ip_local_port_range = 32768    61000
net.ipv4.tcp_max_syn_backlog = 4096
net.ipv4.tcp_max_tw_buckets = 131072

This system isn't under super heavy load currently (about 400 req/sec)
but it has been at max load.