How to use AsyncElasticsearch Connection Pool in FastApi?

Question

The relevant parts of my code are as follows:

@app.on_event("startup")
async def startup():
    es = Translator()
    app.state.es_conn = es.connect()


@app.on_event('shutdown')
async def shutdown_event():
    es = Translator()
    await es.close(app.state.es_conn)


@app.post('/query')
async def query(req: Request):
    es = Translator()
    es.set_conn(req.app.state.es_conn)

    return await es.search()


from elasticsearch import AsyncElasticsearch, AsyncTransport

class Translator(object):
    def __init__(self):
        self.__es = None

    def connect(self):
        return AsyncElasticsearch(
            hosts='http://192.168.0.2:9200/',
            transport_class=AsyncTransport)

    def set_conn(self, conn):
        self.__es = conn

    async def close(self, conn):
        await conn.close()
        self.__es = None

    async def search(self):
        return await self.__es.search(index=index, body=body)

It runs in the following environment:

• PyPy 7.3.7
• fastapi 0.73.0
• Elasticsearch 7.10.1

My question are:

1. Although the code can work normally, how can I detect whether it uses connection pool?
2. How to use connection pool correctly when asynchronous?

Can anyone help me? Thank you!