When attempting to enable HAProxy statistics in version 1.7 on Ubuntu 16.04 LTS, the service fails to start with the following critical errors:

Job for haproxy.service failed because the control process exited with error code
Service started too quickly error
ExecStartPre=/usr/sbin/haproxy -f ${CONFIG} -c -q (code=exited, status=1/FAILURE)

The issue specifically occurs when adding the listen stats block. Here's the problematic section from haproxy.cfg:

listen stats :9000
    mode http
    stats enable
    stats hide-version
    stats realm HAproxy-Statistics
    stats uri /haproxy_stats
    stats auth admin:password

There are two primary issues in the configuration:

1. The listen stats :9000 syntax is incorrect for HAProxy 1.7
2. Missing proper frontend/backend declarations for statistics

Here's the corrected configuration that works with HAProxy 1.7:

frontend stats
    bind *:9000
    stats enable
    stats hide-version
    stats uri /haproxy_stats
    stats realm HAproxy\ Statistics
    stats auth admin:password
    stats refresh 30s
    stats admin if TRUE
    
backend no-op
    option httpchk OPTIONS * HTTP/1.1\r\nHost:\ example.com

Key differences from the original configuration:

1. Uses proper frontend declaration instead of deprecated listen
2. Explicit bind statement with port 9000
3. Added stats refresh interval
4. Included backend section to avoid empty config warnings
5. Proper escaping for the stats realm space character

After making these changes:

sudo haproxy -f /etc/haproxy/haproxy.cfg -c
sudo systemctl restart haproxy

Verify the statistics page is accessible at:

http://your-server-ip:9000/haproxy_stats

For production environments, consider these enhancements:

frontend stats
    bind 127.0.0.1:9000  # Restrict to localhost
    acl internal_network src 192.168.1.0/24
    http-request deny unless internal_network
    stats admin if LOCALHOST  # Only allow admin from localhost

If issues persist, check:

1. File permissions on /run/haproxy/admin.sock
2. SELinux/AppArmor restrictions
3. Port 9000 availability (netstat -tulnp)
4. HAProxy logs (/var/log/haproxy.log)
5. Systemd journal: journalctl -u haproxy -f

When configuring HAProxy 1.7 statistics on Ubuntu 16.04, many developers encounter the frustrating "Service started too quickly" error. The core issue stems from either configuration syntax errors or systemd service conflicts, not necessarily from the statistics module itself.

Let's examine a working configuration that resolves the startup issue while maintaining statistics functionality:

global
    log /dev/log    local0
    log /dev/log    local1 notice
    chroot /var/lib/haproxy
    stats socket /run/haproxy/admin.sock mode 660 level admin
    stats timeout 30s
    user haproxy
    group haproxy
    daemon

defaults
    log global
    mode    http
    option  httplog
    option  dontlognull
    timeout connect 5000
    timeout client  50000
    timeout server  50000

frontend http-in
    bind *:80
    default_backend servers

backend servers
    balance roundrobin
    server server1 127.0.0.1:8080 check
    server server2 127.0.0.1:8081 check

listen stats
    bind *:9000
    mode http
    stats enable
    stats hide-version
    stats uri /stats
    stats realm Haproxy\ Statistics
    stats auth admin:securepassword

1. The listen stats section must include the bind *:9000 directive explicitly
2. Authentication credentials should use proper escaping for special characters
3. Verify socket permissions match the configured user/group

Create or modify /etc/systemd/system/haproxy.service.d/override.conf:

[Service]
RestartSec=5s
TimeoutStartSec=300

Then reload systemd:

sudo systemctl daemon-reload
sudo systemctl restart haproxy

After making these changes, verify the statistics page is accessible:

curl -u admin:securepassword http://localhost:9000/stats

Check the process status:

sudo systemctl status haproxy

And examine the socket:

sudo netstat -tulnp | grep haproxy