# Using Asyncio with Elasticsearch

Starting in `elasticsearch-py` v7.8.0 for Python 3.6+ the `elasticsearch` package supports async/await with Asyncio and Aiohttp. You can either install `aiohttp` directly or use the `[async]` extra:

>     $ python -m pip install elasticsearch>=7.8.0 aiohttp

>     # - OR -

>     $ python -m pip install elasticsearch[async]>=7.8.0

> Note

> Async functionality is a new feature of this library in v7.8.0+ so please open an issue if you find an issue or have a question about async support.

## Getting Started with Async

After installation all async API endpoints are available via `AsyncElasticsearch` and are used in the same way as other APIs, just with an extra `await`:

>     import asyncio
>     from elasticsearch import AsyncElasticsearch

>     es = AsyncElasticsearch()

>     async def main():
>         resp = await es.search(
>             index="documents",
>             query={"match_all": {}},
>             size=20,
>         )
>         print(resp)

>     loop = asyncio.get_event_loop()
>     loop.run_until_complete(main())

All APIs that are available under the sync client are also available under the async client.

## ASGI Applications and Elastic APM

ASGI (Asynchronous Server Gateway Interface) is a new way to serve Python web applications making use of async I/O to achieve better performance. Some examples of ASGI frameworks include FastAPI, Django 3.0+, and Starlette. If you’re using one of these frameworks along with Elasticsearch then you should be using `AsyncElasticsearch` to avoid blocking the event loop with synchronous network calls for optimal performance.

Elastic APM also supports tracing of async Elasticsearch queries just the same as synchronous queries. For an example on how to configure `AsyncElasticsearch` with a popular ASGI framework FastAPI and APM tracing there is a pre-built example in the `examples/fastapi-apm` directory.

## Frequently Asked Questions

### NameError / ImportError when importing `AsyncElasticsearch`?

If when trying to use `AsyncElasticsearch` and you’re receiving a `NameError` or `ImportError` you should ensure that you’re running Python 3.6+ (check with `$ python --version`) and that you have `aiohttp` installed in your environment (check with `$ python -m pip freeze | grep aiohttp`). If either of the above conditions is not met then async support won’t be available.

### What about the `elasticsearch-async` package?

Previously asyncio was supported separately via the elasticsearch-async package. The `elasticsearch-async` package has been deprecated in favor of `AsyncElasticsearch` provided by the `elasticsearch` package in v7.8 and onwards.

### Receiving ‘Unclosed client session / connector’ warning?

This warning is created by `aiohttp` when an open HTTP connection is garbage collected. You’ll typically run into this when closing your application. To resolve the issue ensure that `close()` is called before the `AsyncElasticsearch` instance is garbage collected.

For example if using FastAPI that might look like this:

>     from fastapi import FastAPI
>     from elasticsearch import AsyncElasticsearch

>     app = FastAPI()
>     es = AsyncElasticsearch()

>     # This gets called once the app is shutting down.
>     @app.on_event("shutdown")
>     async def app_shutdown():
>         await es.close()

## Async Helpers

Async variants of all helpers are available in `elasticsearch.helpers` and are all prefixed with `async_*`. You’ll notice that these APIs are identical to the ones in the sync Helpers documentation.

All async helpers that accept an iterator or generator also accept async iterators and async generators.

### Bulk and Streaming Bulk

>     import asyncio
>     from elasticsearch import AsyncElasticsearch
>     from elasticsearch.helpers import async_bulk

>     es = AsyncElasticsearch()

>     async def gendata():
>         mywords = ['foo', 'bar', 'baz']
>         for word in mywords:
>             yield {
>                 "_index": "mywords",
>                 "doc": {"word": word},
>             }

>     async def main():
>         await async_bulk(es, gendata())

>     loop = asyncio.get_event_loop()
>     loop.run_until_complete(main())

>     import asyncio
>     from elasticsearch import AsyncElasticsearch
>     from elasticsearch.helpers import async_streaming_bulk

>     es = AsyncElasticsearch()

>     async def gendata():
>         mywords = ['foo', 'bar', 'baz']
>         for word in mywords:
>             yield {
>                 "_index": "mywords",
>                 "word": word,
>             }

>     async def main():
>         async for ok, result in async_streaming_bulk(es, gendata()):
>             action, result = result.popitem()
>             if not ok:
>                 print("failed to %s document %s" % ())

>     loop = asyncio.get_event_loop()
>     loop.run_until_complete(main())

### Scan

>     import asyncio
>     from elasticsearch import AsyncElasticsearch
>     from elasticsearch.helpers import async_scan

>     es = AsyncElasticsearch()

>     async def main():
>         async for doc in async_scan(
>             client=es,
>             query={"query": {"match": {"title": "python"}}},
>             index="orders-*"
>         ):
>             print(doc)

>     loop = asyncio.get_event_loop()
>     loop.run_until_complete(main())

### Reindex

## API Reference

The API of `AsyncElasticsearch` is nearly identical to the API of `Elasticsearch` with the exception that every API call like `search()` is an `async` function and requires an `await` to properly return the response body.

### AsyncElasticsearch

> Note

> To reference Elasticsearch APIs that are namespaced like `.indices.create()` refer to the sync API reference. These APIs are identical between sync and async.

### AsyncTransport

### AsyncConnection

### AIOHttpConnection