Reference
add server
Available since
- HAProxy 2.4
- HAProxy Enterprise 2.4r1
Add a dynamic server to a backend.
Description Jump to heading
Instantiate a new server attached to an existing backend. Such a server may also be called a dynamic server.
The specified server name must not already be in use in the backend. The backend must be configured to use a dynamic load-balancing algorithm for the balance directive: roundrobin, leastconn, first, or random.
A dynamic server is not restored after a proxy reload operation. If you need the server definition to persist, add it to the load balancer’s configuration file.
Dynamic servers are statically initialized with the none init-addr method. In this method, the server starts in the down state without a valid IP address.
It may be possible to reach the fd (file descriptor) limit when using a large number of dynamic servers. See also fd-hard-limit and ulimit-n in the global keyword documentation.
The following keywords are supported for configuring the new server:
| Keyword | Note | Available since version |
|---|---|---|
| agent-addr | 2.5r1 | |
| agent-check | Even when enabled by this keyword, agent check is still inactive until activated independently of the server with the enable agent command. Note that in this case the server may be activated via the agent depending on the status reported, without an explicit enable server command. This also means that extra care is required when removing a dynamic server with agent check. The agent should first be deactivated using disable agent to be able to put the server in the required maintenance mode before removal. |
2.5r1 |
| agent-inter | 2.5r1 | |
| agent-port | 2.5r1 | |
| agent-send | 2.5r1 | |
| allow-0rtt | 2.5r1 | |
| alpn | 2.5r1 | |
| addr | 2.5r1 | |
| backup | 2.4r1 | |
| ca-file | 2.5r1 | |
| check | Even when enabled by this keyword, health check is still inactive until activated independently of the server with the enable health command. |
2.5r1 |
| check-alpn | 2.5r1 | |
| check-proto | 2.5r1 | |
| check-send-proxy | 2.5r1 | |
| check-sni | 2.5r1 | |
| check-ssl | 2.5r1 | |
| check-via-socks4 | 2.5r1 | |
| ciphers | 2.5r1 | |
| ciphersuites | 2.5r1 | |
| crl-file | 2.5r1 | |
| crt | 2.5r1 | |
| disabled | 2.4r1 | |
| downinter | 2.5r1 | |
| enabled | 2.4r1 | |
| error-limit | 2.5r1 | |
| fall | 2.5r1 | |
| fastinter | 2.5r1 | |
| force-sslv3/tlsv10/tlsv11/tlsv12/tlsv13 | 2.5r1 | |
| id | 2.4r1 | |
| inter | 2.5r1 | |
| maxconn | 2.4r1 | |
| maxqueue | 2.4r1 | |
| minconn | 2.4r1 | |
| no-ssl-reuse | 2.5r1 | |
| no-sslv3/tlsv10/tlsv11/tlsv12/tlsv13 | 2.5r1 | |
| no-tls-tickets | 2.5r1 | |
| npn | 2.5r1 | |
| observe | 2.5r1 | |
| on-error | 2.5r1 | |
| on-marked-down | 2.5r1 | |
| on-marked-up | 2.5r1 | |
| pool-low-conn | 2.4r1 | |
| pool-max-conn | 2.4r1 | |
| pool-purge-delay | 2.4r1 | |
| port | 2.5r1 | |
| proto | 2.4r1 | |
| proxy-v2-options | 2.4r1 | |
| rise | 2.5r1 | |
| send-proxy | 2.4r1 | |
| send-proxy-v2 | 2.4r1 | |
| send-proxy-v2-ssl | 2.5r1 | |
| send-proxy-v2-ssl-cn | 2.5r1 | |
| slowstart | 2.5r1 | |
| sni | 2.5r1 | |
| source | 2.4r1 | |
| ssl | 2.5r1 | |
| ssl-max-ver | 2.5r1 | |
| ssl-min-ver | 2.5r1 | |
| tfo | 2.4r1 | |
| tls-tickets | 2.5r1 | |
| track | A dynamic server may use this keyword to follow the check status of another server from the configuration. However, it is not possible to track another dynamic server. This restriction ensures that the tracking chain is kept consistent in the event a dynamic server is deleted. | 2.5r1 |
| usesrc | 2.4r1 | |
| verify | 2.5r1 | |
| verifyhost | 2.5r1 | |
| weight | 2.4r1 | |
| Ws | 2.5r1 |
Settings from the default-server statement, if any, in the backend configuration are not applied to the new server.
Servers added with this command can be deleted using the del server command.
Examples Jump to heading
Below, we add the server server2 to backend be_test:
bash
bash
See also Jump to heading
If this page was useful, please, Leave the feedback.