health_metric_collector

Overview

This health_metric_collector ROS node collects system metrics and publishes them to /metrics topic. The cloudwatch_metrics_collector node is subscribed to this topic and will publish the metrics to AWS CloudWatch when it is instantiated.

Keywords: ROS, AWS, CloudWatch, Metrics

License

The source code is released under an Apache 2.0.

Author: AWS RoboMaker
Affiliation: Amazon Web Services (AWS)

RoboMaker cloud extensions rely on third-party software licensed under open-source licenses and are provided for demonstration purposes only. Incorporation or use of RoboMaker cloud extensions in connection with your production workloads or commercial product(s) or devices may affect your legal rights or obligations under the applicable open-source licenses. License information for this repository can be found here. AWS does not provide support for this cloud extension. You are solely responsible for how you configure, deploy, and maintain this cloud extension in your workloads or commercial product(s) or devices.

Supported ROS Distributions

• Kinetic
• Melodic

Installation

AWS Credentials

You will need to create an AWS Account and configure the credentials to be able to communicate with AWS services. You may find AWS Configuration and Credential Files helpful. Specifying AWS credentials by setting environment variables is not supported.

This node will require the following AWS account IAM role permissions:

• cloudwatch:PutMetricData

Building from Source

To build from source you'll need to create a new workspace, clone and checkout the latest release branch of this repository, install all the dependencies, and compile. If you need the latest development features you can clone from the master branch instead of the latest release branch. While we guarantee the release branches are stable, the master should be considered to have an unstable build due to ongoing development.

• Install build tool: please refer to colcon installation guide

• Create a ROS workspace and a source directory

    mkdir -p ~/ros-workspace/src
  

• Clone the package into the source directory .

    cd ~/ros-workspace/src
    git clone https://github.com/aws-robotics/health-metrics-collector-ros1.git -b release-latest
  

• Install dependencies

    cd ~/ros-workspace 
    sudo apt-get update && rosdep update
    rosdep install --from-paths src --ignore-src -r -y
  

Note: If building the master branch instead of a release branch you may need to also checkout and build the master branches of the packages this package depends on.

• Build the packages

    cd ~/ros-workspace && colcon build
  

• Configure ROS library Path

    source ~/ros-workspace/install/setup.bash
  

• Build and run the unit tests

    colcon build --packages-select health_metric_collector --cmake-target tests
    colcon test --packages-select health_metric_collector && colcon test-result --all
  

Launch Files

An example launch file called sample_application.launch is included in this project that gives an example of how you can include this node in your project together with the cloudwatch_metrics_collector node.

Usage

Run the node

• With launch file:

  • ROS: roslaunch health_metric_collector sample_application.launch

• Without launch file using default values

  • ROS: rosrun health_metric_collector health_metric_collector

Running the sample application

To launch the sample application for the metrics node you can run the following command:

roslaunch health_metric_collector sample_application.launch --screen

Configuration file and Parameters

The health_metric_collector node receives an interval parameter that indicates the frequency in which it should sample metrics. e.g. interval=5 indicates sampling every five seconds. The default value is 5.

Supported Metrics Types

• Free RAM (in MB)
• Total RAM (in MB)
• Total cpu usage (percentage)
• Per core cpu usage (percentage)
• Uptime (in sec)
• Number of processes

Performance and Benchmark Results

We evaluated the performance of this node by runnning the followning scenario on a Raspberry Pi 3 Model B:

• Launch a baseline graph containing the talker and listener nodes from the roscpp_tutorials package, plus two additional nodes that collect CPU and memory usage statistics. Allow the nodes to run 60 seconds.
• Launch the health_metric_collector ROS node using the launch file sample_application.launch as described above. That launch file also starts a cloudwatch_metrics_collector node, that forwards to the Amazon CloudWatch Metrics service each of the metric messages the health_metric_collector ROS node is publishing to the /metrics topic.
• Allow the nodes to run for 180 seconds.
• Terminate the health_metric_collector and cloudwatch_metrics_collector nodes, and allow the remaining nodes to run for 60 seconds.

The following graph shows the CPU usage during that scenario. After launching the nodes with sample_application.launch, the 1 minute average CPU usage increases from around 7% to a peak of 15%, and stabilizes around 6%, until the nodes are stopped around second 266.

The following graph shows the memory usage during that scenario. We start with a memory usage of 225 MB for the baseline graph, that increases to 251 MB (+11.56%) when sample_application.launch is launched. Memory usage keeps stable until we stop the nodes, and after tthat it goes back to 225 MB.

Node

health_metric_collector

Published Topics

• /metrics

Subscribed Topics

None

Services

None