HAProxy config

haproxy.cfg

global
  log /dev/log  local0
  log /dev/log  local1 notice
  stats socket /run/haproxy/haproxy.sock mode 660 level admin
  stats timeout 2m
  chroot /var/lib/haproxy
  user haproxy
  group haproxy
  daemon

  maxconn 100000
  nbproc 4
  cpu-map 1 0
  cpu-map 2 1
  cpu-map 3 2
  cpu-map 4 3

  # Default SSL material locations
  ca-base /etc/ssl/certs
  crt-base /etc/ssl/private

  # Default ciphers to use on SSL-enabled listening sockets.
  ssl-default-bind-ciphers ...
  ssl-default-bind-options no-sslv3

defaults
  log global
  mode  http
  option  httpchk HEAD /health HTTP/1.1\r\nHost:\ example.com
  option  httplog
  option  dontlognull
  option  forwardfor
  option  http-server-close
  maxconn 5000
  timeout client 30s
  timeout http-keep-alive 500
  timeout http-request 10s      
  timeout server 30s  
  timeout connect 5s
  errorfile 400 /etc/haproxy/errors/400.http
  errorfile 403 /etc/haproxy/errors/403.http
  errorfile 408 /etc/haproxy/errors/408.http
  errorfile 500 /etc/haproxy/errors/500.http
  errorfile 502 /etc/haproxy/errors/502.http
  errorfile 503 /etc/haproxy/errors/503.http
  errorfile 504 /etc/haproxy/errors/504.http

listen stats
  bind :9000
  bind-process 1
  mode http
  stats enable
  stats hide-version
  stats realm Haproxy\ Statistics
  stats uri /
  stats auth ...

frontend www-frontend
  bind :80
  bind :443 ssl crt /etc/ssl/private/example-ev.pem crt-list /etc/haproxy/crtlist
  default_backend www-backend
  compression algo gzip
  compression type text/html text/css text/javascript application/javascript application/json

backend www-backend
  http-request redirect prefix https://%[hdr(host),regsub(^www\.,,i)] if { hdr_beg(host) -i www. }
  redirect scheme https if !{ ssl_fc }
  balance roundrobin
  default-server inter 10s fall 3 rise 2
  server www0 10.129...:80 check
  server www1 10.129...:80 check
  server www2 10.129...:80 check
  server www3 10.129...:80 check
  server www4 10.129...:80 check
  server www5 10.129...:80 check
  server www6 10.129...:80 check
  server www7 10.129...:80 check
  server www8 10.129...:80 check
  server www9 10.129...:80 check

info.txt

$ cat /proc/<PID>/limits
Limit                     Soft Limit           Hard Limit           Units     
Max cpu time              unlimited            unlimited            seconds   
Max file size             unlimited            unlimited            bytes     
Max data size             unlimited            unlimited            bytes     
Max stack size            8388608              unlimited            bytes     
Max core file size        0                    unlimited            bytes     
Max resident set          unlimited            unlimited            bytes     
Max processes             31860                31860                processes 
Max open files            200043               200043               files     
Max locked memory         65536                65536                bytes     
Max address space         unlimited            unlimited            bytes     
Max file locks            unlimited            unlimited            locks     
Max pending signals       31860                31860                signals   
Max msgqueue size         819200               819200               bytes     
Max nice priority         0                    0                    
Max realtime priority     0                    0                    
Max realtime timeout      unlimited            unlimited            us        

$ sudo nc -U /run/haproxy/haproxy.sock
show info
Name: HAProxy
Version: 1.6.3
Release_date: 2015/12/25
Nbproc: 4
Process_num: 3
Pid: 5400
Uptime: 0d 21h08m40s
Uptime_sec: 76120
Memmax_MB: 0
Ulimit-n: 200043
Maxsock: 200043
Maxconn: 100000
Hard_maxconn: 100000
CurrConns: 541
CumConns: 8947429
CumReq: 14122351
MaxSslConns: 0
CurrSslConns: 541
CumSslConns: 8935633
Maxpipes: 0
PipesUsed: 0
PipesFree: 0
ConnRate: 112
ConnRateLimit: 0
MaxConnRate: 416
SessRate: 112
SessRateLimit: 0
MaxSessRate: 416
SslRate: 112
SslRateLimit: 0
MaxSslRate: 416
SslFrontendKeyRate: 50
SslFrontendMaxKeyRate: 380
SslFrontendSessionReuse_pct: 55
SslBackendKeyRate: 0
SslBackendMaxKeyRate: 0
SslCacheLookups: 1826495
SslCacheMisses: 1716050
CompressBpsIn: 12
CompressBpsOut: 120
CompressBpsRateLim: 0
ZlibMemUsage: 0
MaxZlibMemUsage: 0
Tasks: 557
Run_queue: 0
Idle_pct: 75
node: proxy1
description: 

limits.conf

* soft nofile 300000
* hard nofile 300000
root soft nofile 300000
root hard nofile 300000

sysctl.conf

net.core.somaxconn = 100000
net.core.netdev_max_backlog = 100000
net.ipv4.tcp_max_syn_backlog = 100000
net.ipv4.ip_local_port_range = 1024 65535
net.core.wmem_max = 12582912
net.core.rmem_max = 12582912
net.ipv4.tcp_rmem = 10240 87380 12582912
net.ipv4.tcp_wmem = 10240 87380 12582912
fs.file-max = 500000