I use wrk to test cluster performance，both wrk and pod(nginx) are on the same vm。
1、wrk->podIp
./wrk -H "Connection: Close" -t 4 -c 300 -d30 http://{podIp}:80
Running 30s test @ http://{podIp}:80
4 threads and 300 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 20.75ms 24.25ms 838.73ms 97.79%
Req/Sec 2.16k 450.42 3.49k 69.23%
258686 requests in 30.07s, 208.46MB read
Socket errors: connect 0, read 0, write 5, timeout 0
Requests/sec: 8603.95
Transfer/sec: 6.93MB
2、wrk->ClusterIp->pod(only one pod)
10% performance decrease
./wrk -H "Connection: Close" -t 4 -c 300 -d30 http://{ClusterIp}:80
Running 30s test @ http://{ClusterIp}:80
4 threads and 300 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 29.38ms 14.66ms 249.18ms 90.07%
Req/Sec 1.90k 351.30 3.31k 72.35%
227505 requests in 30.05s, 183.34MB read
Requests/sec: 7571.81
Transfer/sec: 6.10MB
2、wrk->ClusterIp->pod(2 pods)
30% performance decrease. In theory, the Requests/sec should be close to 17206(8603 * 2)
./wrk -H "Connection: Close" -t 4 -c 300 -d30 http://{ClusterIp}:80
Running 30s test @ http://{ClusterIp}:80
4 threads and 300 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 13.15ms 8.93ms 106.11ms 73.09%
Req/Sec 3.00k 1.04k 6.32k 68.75%
356342 requests in 30.10s, 287.16MB read
Requests/sec: 11837.60
Transfer/sec: 9.54MB
my configuratin: in /etc/sysctl.conf
net.ipv4.ip_local_port_range = 1024 65000
net.ipv4.tcp_tw_reuse = 1
/etc/security/limits.conf
* soft noproc 102400
* hard noproc 102400
