Pulsar.send() takes long time

[PaiKai-Lee]

framework: expressjs
library: pulsar-client 1.9.0
Pulsar standalone 3.3.7

When user data needs to be updated, I first save the latest state in Redis, and then send an event through Pulsar so the backend can asynchronously synchronize the changes to MySQL.

However, when I use Elastic APM to check the performance, I notice that pulsar.send() takes a surprisingly long time to complete. Even when I only send 2 or 3 requests, it still spends a significant amount of time on this operation.