Document Trio support

Author: pquentin

docs/reference/async.md

@@ -50,6 +50,27 @@ All APIs that are available under the sync client are also available under the a
 
 See also the [Using OpenTelemetry](/reference/opentelemetry.md) page.
 
+## Trio support
+
+If you prefer using Trio instead of asyncio to take advantage of its better structured concurrency support, you can use the HTTPX async node which supports Trio out of the box.
+
+```python
+import trio
+from elasticsearch import AsyncElasticsearch
+
+client = AsyncElasticsearch(
+    "https://...",
+    api_key="...",
+    node_class="httpxasync")
+
+async def main():
+    resp = await client.info()
+    print(resp.body)
+
+trio.run(main)
+```
+
+The one limitation of Trio support is that it does not currently support node sniffing, which was not implemented with structured concurrency in mind.
 
 ## Frequently Asked Questions [_frequently_asked_questions]
 

docs/reference/dsl_how_to_guides.md

@@ -1555,6 +1555,12 @@ The DSL module supports async/await with [asyncio](https://docs.python.org/3/lib
 $ python -m pip install "elasticsearch[async]"
 ```
 
+The DSL module also supports [Trio](https://trio.readthedocs.io/en/stable/) when using the Async HTTPX client. You do need to install Trio and HTTPX separately:
+
+```bash
+$ python -m pip install "elasticsearch trio httpx"
+```
+
 ### Connections [_connections]
 
 Use the `async_connections` module to manage your asynchronous connections.
@@ -1565,6 +1571,14 @@ from elasticsearch.dsl import async_connections
 async_connections.create_connection(hosts=['localhost'], timeout=20)
 ```
 
+If you're using Trio, you need to explicitly request the Async HTTP client:
+
+```python
+from elasticsearch.dsl import async_connections
+
+async_connections.create_connection(hosts=['localhost'], node_class="httpxasync")
+```
+
 All the options available in the `connections` module can be used with `async_connections`.
 
 #### How to avoid *Unclosed client session / connector* warnings on exit [_how_to_avoid_unclosed_client_session_connector_warnings_on_exit]
@@ -1576,8 +1590,6 @@ es = async_connections.get_connection()
 await es.close()
 ```
 
-
-
 ### Search DSL [_search_dsl]
 
 Use the `AsyncSearch` class to perform asynchronous searches.