testing-other-systems.rst

Testing non-HTTP systems

Locust only comes with built-in support for HTTP/HTTPS but it can be extended to test almost any system. This is normally done by wrapping the protocol library and triggering a :pyrequest <locust.event.Events.request> event after each call has completed, to let Locust know what happened.

Note

It is important that the protocol libraries you use can be monkey-patched by gevent.

Almost any libraries that are pure Python (using the Python socket module or some other standard library function like subprocess) should work fine out of the box - but if they do their I/O calls in C, gevent will be unable to patch it. This will block the whole Locust/Python process (in practice limiting you to running a single User per worker process).

Some C libraries allow for other workarounds. For example, if you want to use psycopg2 to performance test PostgreSQL, you can use psycogreen. If you are willing to get your hands dirty, you may also be able to patch a library yourself, but that is beyond the scope of this documentation.

Example: writing an XML-RPC User/client

Lets assume we had an XML-RPC server that we wanted to load test.

../examples/custom_xmlrpc_client/server.py

We can build a generic XML-RPC client, by wrapping :pyxmlrpc.client.ServerProxy.

../examples/custom_xmlrpc_client/xmlrpc_locustfile.py

Example: writing a gRPC User/client

If you have understood the XML-RPC example, you can easily build a gRPC User.

The only significant difference is that you need to make gRPC gevent-compatible, by executing this code before opening the channel:

import grpc.experimental.gevent as grpc_gevent

grpc_gevent.init_gevent()

Dummy server to test:

../examples/grpc/hello_server.py

gRPC client, base User and example usage:

../examples/grpc/locustfile.py

For more examples of user types, see locust-plugins (it has users for WebSocket/SocketIO, Kafka, Selenium/WebDriver and more).