MongoDB Free monitoring on Community version 4.0 explained

I was just playing around with MongoDB 4.0 community version & noticed a feature called free monitoring. In this article let have a detailed look of free monitoring, how to enable, check status and what are the monitoring metrics that are provided by MongoDB.

Free Monitoring:

Free monitoring is a service that is available in the MongoDB 4.0 Community versions. It provides us with some graphical/statistical data related to currently deployed instances which expire after 24 hours. So let's have a look how can we enable free monitoring & look at what is in it.

Enabling Monitoring:

This command enabled the free monitoring in the instance, one-time enabling is enough it is not necessary to enable each time to check the status. 

db.enableFreeMonitoring()

Check Monitoring status:

In order to check the current free monitoring status the above command which let us know the status. When once enabled, the monitored data is uploaded periodically to the cloud & it can be accessed via browsers through the provided URL. 

db.getFreeMonitoringStatus() 

Graph options:

Let's have a look over the various graph parameters that are included in the free monitoring.

Operation Execution:

This lists out the how many times the operations are being executed in the server. Operations include reads, writes & commands.

Disk Utilization:

Every disk has its own read & write speed. Disk utilization involves the sum of the total speed of data that is being written to and read from the disk. This graph plots out the maximum & average disk used by the drives.

Documents:

This returns the stats of the documents that are returned, inserted, updated & deleted

Memory:

MongoDB uses virtual as well as the resident memory. Resident memory is the memory that is used by RAM. In some cases, the operating system returns the imaginary address when MongoDB requests for memory address which is not real. If the journal is enabled then it returns another address for journal data, both together is the Virtual memory. Journal reference memory alone is known as the mapped memory.

Network IO:

This refers to the total network traffic that is being received and sent by MongoDB in bytes.

Opcounters:

Opcounters are nothing but the total list of the operations count that is being performed by the server. It included the operations such as insert, query, update, delete,getmore, commands.

Replicated Opcounters:

This refers the opcounters that are being replicated to the other secondaries in the replica cluster. The value of replicated opcounters will be present only if the instance is a replica set.

Query Targeting:

This chart depicts the query & objects that are scanned by the process.

Queue:

This parameter lists out the total number of reads,writes that are currently waiting under the queue or waiting for any other lock.

System CPU usage:

It explains about the complete system CPU usage with respect to the some of the specialized factors.