Docker Containers - Status Test

Docker containers can be built within seconds based on a Docker image. In large environments where multiple containers are created simultaneously, administrators may actually want to keep track on the containers that are currently running, the containers that are currently stopped, and the containers that were removed etc so that containers that are sparsely used and containers that crashed can be identified easily. The Docker Containers - Status test helps administrators to optimize the containers and enhance the overall performance of the Docker server.

This test monitors the containers available in the Docker server and reports the numerical statistics of the total containers, the containers in Running state, the containers that were added, the containers that were removed etc. In addition, this test reports the containers that are not running for a time duration above the specified limit and the containers that are utilizing disk space above the specified limit. By analyzing this, administrators can figure out the overall performance of the Docker server and identify bottlenecks if any.

Target of the test : A Docker server

Agent deploying the test : An internal/remote agent

Outputs of the test : One set of results for the Docker server being monitored.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The IP address of the host for which this test is to be configured.

Port

The port number at which the specified HOST listens. The default is 2375.

UseSUDO

By default, this flag is set to Yes. You are advised not to change the default setting of this flag.

Docker User and Docker Password

Specify the credentials of the user who is authorized to execute the docker commands on the target server

Size Limit in MB

By default, the disk space utilized by each container may vary according to the size of the container. Sometimes, the containers may be over-utilizing the disk space which when left unnoticed may hamper the creation of new containers. To figure out such containers, you can specify a disk space limit beyond which the containers can be termed as large sized container. For example, if you wish to monitor the number of containers that are utilizing disk space above 50 MB, then specify 50 against this text box.

Time Limit in Weeks

For this test to report the numerical statistics of the containers that were not started/running, set a valid value against this parameter. For example, if you wish to report the containers that were not started for more than 3 weeks, then set 3 against this text box.

DD Frequency

Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD frequency.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enabled/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Total containers

Indicates the total number of containers in this server.

Number

The detailed diagnosis of this measure if enabled, lists the name of the container, the container ID, the image used to create the container, the container creation time, the status of the container and the size of the container.

Running containers

Indicates the number of containers that are in Running state.

Number

A high value of this measure indicates that more number of containers are in running state as a result more number of applications can be accessed actively. To know which containers are currently running, use the detailed diagnosis capability of this measure.

Stopped containers

Indicates the number of containers that are currently not running in this server.

Number

To know more about the containers that are currently not running, use the detailed diagnosis capability of this measure (if enabled).

Added containers

Indicates the number of containers that were created during the last measurement period.

Number

The detailed diagnosis of this measure, if enabled, lists the names of the containers that were created.

Removed containers

Indicates the number of containers that were removed from this server during the last measurement period.

Number

The detailed diagnosis of this measure, if enabled, lists the containers that were removed.

If too many containers are removed, then the users may not be able to access the hosted applications thus leading to a performance bottleneck of the Docker server. Administrators are therefore required to keep a check on the containers that are removed from the Docker server.

Large size containers

Indicates the number of containers that were using more disk space than the limit configured against the Size Limit in MB parameter.

Number

A low value is desired for this measure. The detailed diagnosis of this measure if enabled, lists the names of the containers that are over-utilizing the disk space.

Containers not started for long time

Indicates the number of containers that were not running for more than the configured Time Limit in Weeks.

Number

Ideally, the value of this measure should be low. The detailed diagnosis of this measure if enabled, lists the containers that are not running for longer time.

The detailed diagnosis of the Total Containers measure lists all the containers that were created and the images that were used to create those containers.

Figure 1 : The detailed diagnosis of the Total Containers measure