Running and Verifying HAProxy

1. Back up the option-http_proxy.cfg file.

   1	mv /usr/local/haproxy/conf/option-http_proxy.cfg /usr/local/haproxy/conf/option-http_proxy.cfg_bak

2. Create an option-http_proxy.cfg file.

   1	vi /usr/local/haproxy/conf/option-http_proxy.cfg

3. Modify the file as follows (Replace IP1:PORT1 and IP2:PORT2 with the actual values), and save the file and exit.

   global
   maxconn      20000
   log               127.0.0.1 local0  info
   uid               0
   gid               0
   chroot          /usr/local/haproxy
   nbproc          4
   daemon
   defaults
   mode                       http
   retries                      3
   timeout connect      10s
   timeout client          20s
   timeout server         30s
   timeout check          2s
   frontend test-proxy
   bind            *:80
   mode            http
   log             global
   default_backend test-proxy-srv
   backend test-proxy-srv
   balance        roundrobin
   option http-server-close
   option httpchk   GET /index.html
   http-check expect       status 200
   server          web1    IP1:PORT1 weight 3
   server          web2    IP2:PORT2 weight 3

   Table 1 describes the parameters in the configuration file.

   Table 1 Example configuration file and parameter description

   Parameter	Description
   global	-
   maxconn 20000	Specifies the maximum number of connections.
   log 127.0.0.1 local0 info	Specifies the log output device. info indicates the log severity level.
   uid 0	Specifies the ID of the user who runs HAProxy.
   gid 0	Specifies the ID of the user group to which the user running HAProxy belongs.
   chroot /usr/local/haproxy	Specifies the chroot running path.
   nbproc 4	Specifies the number of processes.
   daemon	Runs HAProxy in the background.
   defaults	-
   mode http	Specifies the processed type (layer 7 uses HTTP, and layer 4 uses TCP).
   retries 3	Specifies the maximum number of retry times for connecting to the backend server. If the number of retry times exceeds the specified value, the backend server is unavailable.
   timeout connect 10s	Specifies the maximum time allowed before a connection is set up between HAProxy and the backend server
   timeout client 20s	Specifies the timeout period for keeping an idle connection with the client.
   timeout server 30s	Specifies the timeout period for keeping an idle connection with the server.
   timeout check 2s	Specifies the timeout period for checking the server.
   frontend test-proxy	-
   bind *:80	Specifies one or more listening sockets. The asterisk (*) indicates all IPv4 addresses.
   mode http	Specifies the processed type (layer 7 uses HTTP, and layer 4 uses TCP).
   log global	Inherits the definition of log in the global section.
   default_backend test-proxy-srv	Specifies the default backend server pool.
   backend test-proxy-srv	-
   balance roundrobin	Specifies the load balancing algorithm roundrobin, which is a weight-based polling algorithm and applies to scenarios where server performance is even.
   option http-server-close	Enables this function when persistent connection is enabled.
   option httpchk GET /index.html http-check expect status 200	Enables HTTP service status check (health check). Checks the returned status code. If "200" is not received, the request is not scheduled to backend servers.
   server web1 IP1:PORT1 weight 3 server web2 IP2:PORT2 weight 3	Defines multiple backend servers. Format: server <name> <address>:[port] [param*] NOTE: IP1:PORT1 and IP2:PORT2 indicate the IP addresses and port numbers of the backend servers.

1

ps -ef | grep haproxy

The HAProxy process is displayed.

Open the browser, enter http://HAProxy IP address:80 in the address box and press Enter. The WebUI page of the backend server is displayed, indicating that HAProxy is running properly. Refresh the page. The page switches between backend servers.

• (Optional) Run the following command to stop HAProxy. Do not run this command when services are running.

  1	pkill haproxy