Monitoring

Overview

In this guide, you can learn how to configure monitoring in PyMongo by using PyMongo's callback-based interface. Monitoring is the process of gathering information about your application's behavior as it runs. This information can help you make informed decisions when designing and debugging your application. You can also use information from monitoring events to track your application's performance and resource usage.

The driver provides information about your application by emitting events. You can listen for driver events to monitor your application.

Event Types

The type of event that the driver emits depends on the operation being performed. The following table describes the types of events that the driver emits:

For a complete list of events the driver emits, see the pymongo.monitoring API documentation.

Listening for Events

To monitor an event, you must pass an event listener to your application's MongoClient. The following steps describe how to monitor your application by using an event listener:

1. Create a class that inherits from one of the event listener base classes provided by PyMongo. The base class you choose depends on the type of event you want to monitor. For example, to monitor command events, create a class that inherits from CommandListener.

2. Implement the methods of the base class that correpond to the events you want to monitor.

3. Pass an instance of your listener class to the MongoClient constructor.

The following code implements a CommandListener to listen for command events, a ServerListener to listen for SDAM events, and a ConnectionPoolListener to listen for connection pool events:

class MyCommandListener(CommandListener):
    def succeeded(self, event: CommandSucceededEvent):
        print(f"Command {event.command_name} succeeded")
    # Include other event method implementations here
class MyServerListener(ServerListener):
    def heartbeat_started(self, event: ServerHeartbeatStartedEvent):
        print(f"Heartbeat started on server with id: {event.connection_id}")
    # Include other event method implementations here
class MyPoolListener(ConnectionPoolListener):
    def connection_created(self, event: ConnectionCreatedEvent):
        print(f"Connection {event.connection_id} created")
    # Include other event method implementations here
listeners = [MyCommandListener(), MyServerListener(), MyPoolListener()]
client = MongoClient("<connection URI>", event_listeners=listeners)

API Documentation

To learn more about the methods and classes used to monitor events in the driver, see the following API documentation:

• monitoring

• MongoClient