haproxy.rst (1662B)
1 Deploy behind HAProxy 2 ===================== 3 4 This guide demonstrates a way to load balance connections across multiple 5 websockets server processes running on the same machine with HAProxy_. 6 7 We'll run server processes with Supervisor as described in :doc:`this guide 8 <supervisor>`. 9 10 .. _HAProxy: https://www.haproxy.org/ 11 12 Run server processes 13 -------------------- 14 15 Save this app to ``app.py``: 16 17 .. literalinclude:: ../../example/deployment/haproxy/app.py 18 :emphasize-lines: 24 19 20 Each server process listens on a different port by extracting an incremental 21 index from an environment variable set by Supervisor. 22 23 Save this configuration to ``supervisord.conf``: 24 25 .. literalinclude:: ../../example/deployment/haproxy/supervisord.conf 26 27 This configuration runs four instances of the app. 28 29 Install Supervisor and run it: 30 31 .. code-block:: console 32 33 $ supervisord -c supervisord.conf -n 34 35 Configure and run HAProxy 36 ------------------------- 37 38 Here's a simple HAProxy configuration to load balance connections across four 39 processes: 40 41 .. literalinclude:: ../../example/deployment/haproxy/haproxy.cfg 42 43 In the backend configuration, we set the load balancing method to 44 ``leastconn`` in order to balance the number of active connections across 45 servers. This is best for long running connections. 46 47 Save the configuration to ``haproxy.cfg``, install HAProxy, and run it: 48 49 .. code-block:: console 50 51 $ haproxy -f haproxy.cfg 52 53 You can confirm that HAProxy proxies connections properly: 54 55 .. code-block:: console 56 57 $ PYTHONPATH=src python -m websockets ws://localhost:8080/ 58 Connected to ws://localhost:8080/. 59 > Hello! 60 < Hello! 61 Connection closed: 1000 (OK).