Overview

Several third-party tools are available to manage and display the metrics produced by Kill Bill. However, one popular tool available directly from AWS is CloudWatch. This package enables you to monitor and display whatever metrics you may find useful from the Kill Bill collection, including metrics that show the performance and resource use of Kill Bill and Kaui themselves, and metrics describing the infrastructure on which these systems run. CloudWatch is included automatically in the Kill Bill CloudFormation option, but it can be used with the other AWS options as well.

In this guide we discuss the use of CloudWatch to manage metrics produced by single-tier and multi-tier implementations on Amazon Web Services (AWS). The latest Amazon Machine Image (AMI) for Kill Bill is preconfigured to direct the Kill Bill metrics to CloudWatch and work with them in the way that best suits your needs. These instructions apply to the Kill Bill AMI version 2021.9 or later.

To set up CloudWatch to manage the metrics available from Kill Bill, there are five steps:

  1. Edit a configuration file to enable the use of CloudWatch.

  2. Install the AWS X-Ray daemon

  3. Create an IAM policy

  4. Create an IAM role

  5. Attach the role to your EC2 instance(s)

Edit the Configuration File

To authorize the sending of the Kill Bill metrics to CloudWatch, it is necessary to edit just one line in this file:

/var/lib/tomcat/bin/setenv2.sh

This file contains configuration information for tomcat, which manages the KillBill web applications.

This is a small file. The line to be edited is:

-Dcom.killbill.cloudwatch.enable=false

This should be changed to:

-Dcom.killbill.cloudwatch.enable=true

After editing the file, go to your AWS EC2 dashboard and reboot the instance so the new configuration file will be read. If you have more than one instance, follow the same procedure for each one.

Install the X-Ray daemon

AWS X-Ray is a service that collects and analyzes data from your applications. A daemon is a process that runs in the background to do a job whenever it is needed. The X-Ray daemon uploads application metrics to X-Ray in batches to be processed. X-Ray then forwards this data to CloudWatch for display.

To setup the daemon, log in to your EC2 instance and run the following commands:

curl https://s3.dualstack.us-east-1.amazonaws.com/aws-xray-assets.us-east-1/xray-daemon/aws-xray-daemon-3.x.deb -o /home/ubuntu/xray.deb
sudo dpkg -i /home/ubuntu/xray.deb

If you have more than one instance, repeat these commands on each one.

Create an IAM Policy

This step creates a policy, or a set of permissions, that is required to access the Kill Bill metrics.

  1. From the EC2 Dashboard, Type "IAM" in the search field at the upper left. Select the IAM Dashboard.

  2. From the left menu, choose Policies, then select Create Policy.

  3. On the page that appears, select the JSON tab. You should see:

    create iam policy

  4. Next, copy the following lines between the square brackets:

            {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeTags",
                "cloudwatch:PutMetricData",
                "xray:GetSamplingRules",
                "xray:GetSamplingTargets",
                "xray:GetSamplingStatisticSummaries",
                "xray:PutTraceSegments",
                "xray:PutTelemetryRecords",
                "logs:CreateLogGroup",
                "logs:CreateLogStream",
                "logs:DescribeLogGroups",
                "logs:DescribeLogStreams",
                "logs:PutLogEvents"
            ],
            "Resource": "*"
        }

  5. Choose Next:Tags. Then on the next page, click Next:Review.

  6. Now give your policy a name, such as "CloudWatch_Policy". Then click Create Policy.

Your policy will be created.

Create an IAM Role

A role is an identity that has specific permissions defined by a policy. A role can be used to define the permissions for an EC2 instance.

  1. Return to the IAM Dashboard.

  2. From the left menu, choose Roles, then select Create Role. You should see: