Enhanced MongoDB monitoring

Published March 30, 2016 Updated March 12, 2020 3 min read

Karolina Ruszkowska-Cyrzan

We’re happy to announce the availability of enhanced Dynatrace MongoDB monitoring. MongoDB monitoring provides you with a good understanding of your MongoDB performance and its impact on your applications.

Viewing MongoDB monitoring metrics

Captured MongoDB metrics are displayed on MongoDB Process pages. Click the infographic, or click the MongoDB metrics and Further details tabs to view metric details.

MongoDB

Collected metrics

Metric	Description
Current connections	Reflects number of incoming connections from clients to the database server, including the current shell session. Provides insight into the connection load on the database.
Available connections	Number of available unused incoming connections.
Asserts	Regular – Number of regular assertions raised since the MongoDB process started. Warning – Number of warning assertions raised since the MongoDB process started. Message – Number of message assertions raised since the MongoDB process started. User – Number of user assertions raised since the MongoDB process started. These are errors that user may generate, for instance duplicate key or out of disk space. Rollover – Number of times that the rollover counters have rolled over per second.
Current queue	Number of operations queued waiting for the lock. A consistently high value indicates a possible concurrency issue that may be affecting performance.
Active clients	Number of connected clients and the read and write operations performed by these clients.
Resident memory	Value is roughly equivalent to the amount of RAM, which is currently used by the database process.
Virtual memory	Amount of virtual memory used by the mongod process.
Operations	Insert – Number of insert operations per second. Query – Number of queries per second. Update – Number of update operations per second. Delete – Number of delete operations per second. Getmore – Number of getmore operations per second. Command – Number of commands per second issued to the database.

Database-level metrics

Metric	Description
Objects	Number of documents in the database across all collections.
Indexes	Total number of indexes in the database across all collections.
Data size	Total size (bytes) of data held in the database.
Storage size	Amount of space (bytes) allocated to collections in this database for document storage. The storage size doesn’t decrease as documents are removed or reduced.
Index size	Total size (bytes) of all indexes created on this database.

MongoDB

Prerequisites

MongoDB 2.6 (or higher)
OneAgent 1.89 (or higher)
Privileges: User must have the clusterMonitor role for the admin database.

Configuring MongoDB monitoring

There are two configuration options available for MongoDB monitoring:

global (applicable to all hosts) The main advantage of using the global configuration option is that, once configured, when a new host running MongoDB is detected in the future, monitoring will be activated and metrics will be gathered automatically.
local (specific hosts only)

To enable MongoDB monitoring globally (recommended):

From the navigation menu, select Settings.
Select Monitored technologies.
Click Edit next to the Configure MongoDB extension listing.
Enter the User and Password needed to connect to the MongoDB server.
Click Save.
Set the MongoDB switch to On to enable monitoring.
Ensure that the Extensions manager switch is also set to the On position.

To enable MongoDB monitoring locally:

Note: Before proceeding, ensure that the Configure MongoDB global configuration option (explained above) is set to the Off position.

Go to a MongoDB Host page.
Click Edit to configure MongoDB locally.
Expand the MongoDB extension listing.
Follow steps 4-7 as explained above for global configuration.