Skip to content

DOCSP-45009 - Cluster Monitoring #361

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 6 commits into from
Dec 12, 2024
Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 3 additions & 1 deletion source/fundamentals.txt
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,7 @@ Fundamentals
Store Large Files </fundamentals/gridfs>
Replica Set Operations </fundamentals/read-write-configuration>
OData </fundamentals/odata>
Monitoring </fundamentals/monitoring>

- :ref:`Connecting to MongoDB <csharp-connection>`
- :ref:`csharp-db-coll`
Expand All @@ -53,4 +54,5 @@ Fundamentals
- :ref:`csharp-geo`
- :ref:`csharp-gridfs`
- :ref:`csharp-read-write-config`
- :ref:`csharp-odata`
- :ref:`csharp-odata`
- :ref:`csharp-monitoring`
114 changes: 114 additions & 0 deletions source/fundamentals/monitoring.txt
Original file line number Diff line number Diff line change
@@ -0,0 +1,114 @@
.. _csharp-monitoring:

==========
Monitoring
==========

.. facet::
:name: genre
:values: reference

.. meta::
:keywords: event, subscribe, listener

.. contents:: On this page
:local:
:backlinks: none
:depth: 2
:class: singlecol

Overview
--------

On this page, you can learn how to configure **monitoring** in the
{+driver-long+}. Monitoring is the process of gathering information about your
application's performance and resource usage as it runs.
This can help you make informed decisions when designing and debugging your application.

The driver provides information about your application by emitting events. You can
subscribe to these driver events to monitor your application.

.. note:: Event Logging

This page explains how to monitor your application in code. To learn how to record
this information to an external log, see :ref:`Logging. <csharp-logging>`

.. _csharp-event-types:

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:

.. list-table::
:header-rows: 1
:widths: 30 70

* - Event Type
- Description
* - Command Events
- Events related to MongoDB database commands, such as ``find``, ``insert``,
``delete``, and ``count``. To learn how to use the {+driver-short+} to run a
database command, see :ref:`<csharp-run-command>`. For more information about
MongoDB database commands, see :manual:`Database Commands </reference/command/>`
in the {+mdb-server+} manual.

As a security measure, the driver redacts the contents of some
command events. This protects the sensitive information contained in these command
events.

* - Server Discovery and Monitoring (SDAM) Events
- Events related to changes in the state of the MongoDB deployment.

* - Connection Pool Events
- Events related to the connection pool held by the driver.

For a complete list of events the driver emits, see the API documentation for the
`MongoDB.Driver.Core.Events <{+new-api-root+}/MongoDB.Driver/MongoDB.Driver.Core.Events.html>`__
namespace.

.. _csharp-monitor-events:

Subscribing to Events
---------------------

To monitor an event, you must subscribe a listener method on your ``MongoClient`` instance.
The following steps describe how to subscribe to events:

1. Create a ``MongoClientSettings`` object.
#. Set the ``ClusterConfigurator`` property on the ``MongoClientSettings`` object to a
lambda function that accepts a ``ClusterBuilder`` object.
#. In the lambda function, call the ``Subscribe<TEvent>()``
method on the ``ClusterBuilder`` object for each event you want to subscribe to.
Replace ``TEvent`` with the event type. Pass the event handler
method as an argument to the ``Subscribe<TEvent>()`` method.

The following code example shows how to subscribe to the ``ClusterOpenedEvent``,
``ServerHeartbeatSucceededEvent``, and ``ConnectionPoolReadyEvent``. This example
assumes that the ``ClusterEventHandler``, ``HeartbeatEventHandler``,
and ``ConnectionPoolEventHandler`` methods are defined elsewhere in your code.

.. code-block:: csharp

var clientSettings = MongoClientSettings.FromConnectionString(MongoConnectionString);
Copy link
Collaborator Author

@mongoKart mongoKart Dec 6, 2024

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Tech reviewer: Does the event-subscription process look any different in pre-3.0 driver versions? Or can I backport this all the way to 2.19?

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Users should have been using this event-subscription process even prior 3.0 driver. There is only one case where users could subscribe to a ClusterDescriptionChangedEvent directly through Client.Cluster since the cluster used to expose its DescriptionChanged handler. But we removed that in 3.0 and there are no other ways for users to subscribe to events other than through ClusterBuilder.

Copy link
Collaborator Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Thanks. I'll backport this page all the way to v2.22 then.

clientSettings.ClusterConfigurator = clusterBuilder =>
{
clusterBuilder
.Subscribe<ClusterOpenedEvent>(ClusterEventHandler)
.Subscribe<ServerHeartbeatSucceededEvent>(HeartbeatEventHandler)
.Subscribe<ConnectionPoolReadyEvent>(ConnectionPoolEventHandler);
};

.. tip::

You can subscribe to any number of events, and these events can be of different types.

API Documentation
-----------------

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

- `MongoDB.Driver.Core.Events <{+new-api-root+}/MongoDB.Driver/MongoDB.Driver.Core.Events.html>`__
- `Subscribe<TEvent>() <{+new-api-root+}/MongoDB.Driver/MongoDB.Driver.Core.Configuration.ClusterBuilder.Subscribe.html>`__
Loading