Using with asyncio
editUsing with asyncio
editThe 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 aiohttp # - OR - $ python -m pip install elasticsearch[async]
Getting Started with Async
editAfter installation all async API endpoints are available via
~elasticsearch.AsyncElasticsearch and are used in the same way as
other APIs, with an extra await:
import asyncio
from elasticsearch import AsyncElasticsearch
client = AsyncElasticsearch()
async def main():
resp = await client.search(
index="documents",
body={"query": {"match_all": {}}},
size=20,
)
print(resp)
asyncio.run(main())
All APIs that are available under the sync client are also available under the async client.
ASGI Applications and Elastic APM
editASGI (Asynchronous Server Gateway
Interface) is a 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 ~elasticsearch.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.
See also the Using OpenTelemetry page.
Frequently Asked Questions
editValueError when initializing AsyncElasticsearch?
editIf when trying to use AsyncElasticsearch you receive
ValueError: You must have 'aiohttp' installed to use AiohttpHttpNode
you should ensure that you have aiohttp installed in your environment
(check with $ python -m pip freeze | grep aiohttp). Otherwise,
async support won’t be available.
What about the elasticsearch-async package?
editPreviously 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?
editThis 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
~elasticsearch.AsyncElasticsearch.close is called before the
~elasticsearch.AsyncElasticsearch instance is garbage collected.
For example if using FastAPI that might look like this:
import os
from contextlib import asynccontextmanager
from fastapi import FastAPI
from elasticsearch import AsyncElasticsearch
ELASTICSEARCH_URL = os.environ["ELASTICSEARCH_URL"]
client = None
@asynccontextmanager
async def lifespan(app: FastAPI):
global client
client = AsyncElasticsearch(ELASTICSEARCH_URL)
yield
await client.close()
app = FastAPI(lifespan=lifespan)
@app.get("/")
async def main():
return await client.info()
You can run this example by saving it to main.py and executing
ELASTICSEARCH_URL=http://localhost:9200 uvicorn main:app.
Async Helpers
editAsync 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 Client helpers documentation.
All async helpers that accept an iterator or generator also accept async iterators and async generators.