monitoring – Tools for monitoring driver events.

Tools to monitor driver events.

Use register() to register global listeners for specific events. Currently only command events are published. Listeners must be a subclass of CommandListener and implement started(), succeeded(), and failed().

For example, a simple command logger might be implemented like this:

import logging

from pymongo import monitoring

class CommandLogger(monitoring.CommandListener):

    def started(self, event):
        logging.info("Command {0.command_name} with request id "
                     "{0.request_id} started on server "
                     "{0.connection_id}".format(event))

    def succeeded(self, event):
        logging.info("Command {0.command_name} with request id "
                     "{0.request_id} on server {0.connection_id} "
                     "succeeded in {0.duration_micros} "
                     "microseconds".format(event))

    def failed(self, event):
        logging.info("Command {0.command_name} with request id "
                     "{0.request_id} on server {0.connection_id} "
                     "failed in {0.duration_micros} "
                     "microseconds".format(event))

monitoring.register(CommandLogger())

Event listeners can also be registered per instance of MongoClient:

client = MongoClient(event_listeners=[CommandLogger()])

Note that previously registered global listeners are automatically included when configuring per client event listeners. Registering a new global listener will not add that listener to existing client instances.

Note

Events are delivered synchronously. Application threads block waiting for event handlers (e.g. started()) to return. Care must be taken to ensure that your event handlers are efficient enough to not adversely affect overall application performance.

Warning

The command documents published through this API are not copies. If you intend to modify them in any way you must copy them in your event handler first.

pymongo.monitoring.register(listener)

Register a global event listener.

Parameters :
class pymongo.monitoring.CommandListener

Abstract base class for command listeners.

failed(event)

Abstract method to handle CommandFailedEvent.

Parameters :
started(event)

Abstract method to handle CommandStartedEvent.

Parameters :
succeeded(event)

Abstract method to handle CommandSucceededEvent.

Parameters :
class pymongo.monitoring.CommandStartedEvent(command, database_name, *args)

Event published when a command starts.

Parameters :
  • command: The command document.
  • database_name: The name of the database this command was run against.
  • request_id: The request id for this operation.
  • connection_id: The address (host, port) of the server this command was sent to.
  • operation_id: An optional identifier for a series of related events.
command

The command document.

command_name

The command name.

connection_id

The address (host, port) of the server this command was sent to.

database_name

The name of the database this command was run against.

operation_id

An id for this series of events or None.

request_id

The request id for this operation.

class pymongo.monitoring.CommandSucceededEvent(duration, reply, command_name, request_id, connection_id, operation_id)

Event published when a command succeeds.

Parameters :
  • duration: The command duration as a datetime.timedelta.
  • reply: The server reply document.
  • command_name: The command name.
  • request_id: The request id for this operation.
  • connection_id: The address (host, port) of the server this command was sent to.
  • operation_id: An optional identifier for a series of related events.
command_name

The command name.

connection_id

The address (host, port) of the server this command was sent to.

duration_micros

The duration of this operation in microseconds.

operation_id

An id for this series of events or None.

reply

The server failure document for this operation.

request_id

The request id for this operation.

class pymongo.monitoring.CommandFailedEvent(duration, failure, *args)

Event published when a command fails.

Parameters :
  • duration: The command duration as a datetime.timedelta.
  • failure: The server reply document.
  • command_name: The command name.
  • request_id: The request id for this operation.
  • connection_id: The address (host, port) of the server this command was sent to.
  • operation_id: An optional identifier for a series of related events.
command_name

The command name.

connection_id

The address (host, port) of the server this command was sent to.

duration_micros

The duration of this operation in microseconds.

failure

The server failure document for this operation.

operation_id

An id for this series of events or None.

request_id

The request id for this operation.

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