Mongo Connections Test

Monitoring client connections to a MongoDB server typically provide insights into the workload of the server and whether/not the server is sized well-enough to handle the load. This is exactly the type of visibility the Mongo Connections test provides. This test tracks client connections to the target server and reports their usage. With the help of the metrics reported by this test, administrators can assess the load on the server and can determine whether/not the server has sufficient free connections to handle subsequent connection requests. Based on these insights, administrators can plan the future connection capacity of the server.

Target of the test : A MongoDB server

Agent deploying the test : An internal/remote agent

Outputs of the test : One set of results for the Mongo database server being monitored

Configurable parameters for the test
Parameter	Description
Test period	How often should the test be executed
Host	The host for which the test is to be configured.
Port	The port number at which the specified host listens
Database Name	The test connects to a specific Mongo database to run API commands and pull metrics of interest. Specify the name of this database here. The default value of this parameter is admin.
Username and Password	The eG agent has to be configured with the credentials of a user who has the required privileges to monitor the target MongoDB instance, if the MongoDB instance is access control enabled. To know how to create such a user, refer to How to monitor access control enabled MongoDB database?. If the target MongoDB instance is not access control enabled, then, specify none against the Username and Password parameters.
Confirm Password	Confirm the password by retyping it here.
Authentication Mechanism	Typically, the MongoDB supports multiple authentication mechanisms that users can use to verify their identity. In environments where multiple authentication mechanisms are used, this test enables the users to select the authentication mechanism of their interest using this list box. By default, this is set to None. However, you can modify this settings as per the requirement.
SSL	By default, the SSL flag is set to No, indicating that the target MongoDB server is not SSL-enabled by default. To enable the test to connect to an SSL-enabled MongoDB server, set the SSL flag to Yes.
CA File	A certificate authority (CA) file contains root and intermediate certificates that are electronically signed to affirm that a public key belongs to the owner named in the certificate. If you are looking to monitor the certificates contained within a CA file, then provide the full path to this file in the CA File text box. For example, the location of this file may be: C:\cert\rootCA.pem. If you do not want to monitor the certificates in a CA file, set this parameter to none.
Certificate Key File	A Certificate Key File specifies the path on the server where your private key is stored. If you are looking to monitor the Certificate Key File, then provide the full path to this file in the Certificate Key File text box. For example, the location of this file may be: C:\cert\mongodb.pem. If you do not want to monitor the certificates in a CA file, set this parameter to none.

Measurements made by the test
Measurement	Description	Measurement Unit	Interpretation
Total connections	Indicates the total number of incoming connections to the server.	Number	This is the sum of the values of the Open connections and Free connections measure.
Open connections	Indicates the count of incoming connections from clients to the server.	Number	This is a good measure of the current load on the server. The value will include all incoming connections including any shell connections or connections from other servers, such as replica set members or mongos instances.
Free connections	Indicates the number of unused connections.	Number	The value 0 or a very low value for this measure is a cause for concern, as it indicates that there are no (or very few) free connections to handle subsequent connection requests. You may want to increase the maximum number of connections the server can handle, so that connection requests are not rejected.
Connection usage	Indicates the percentage of total connections that is in use.	Percent	A value close to 100% is indicative of over-utilization of connections. This in turn means that there are there are no (or very few) free connections to handle subsequent connection requests. You may want to increase the maximum number of connections the server can handle, so that connection requests are not rejected. The value of this measure is calculated using the formula: (Open connections / Total connections)*100