As we previously announced, our new Elastigroup HCS service is now released.
In this post you will find the steps you need to follow in order to configure the service in your VPC.
So, let’s get started.
The Spotinst Health Check service will be installed on your VPC. You should open traffic from your Elastigroup to Spotinst Security Group and to one of your instances that will be assigned as a Security Group.
How it works
The Spotinst Health Check service will act as a proxy between Spotinst hosts and your
EC2 private instances in your VPC.
Spotinst will trigger the proxy service on each check. The proxy will communicate with your private instances in the VPC and will send the results to Spotinst.
When an instance is marked as unhealthy, and the Elastigroup Health Check type is set to
CUSTOM, Spotinst will replace it with a new instance according to the Elastigroup config.
Follow these steps to configure Spotinst Health Check:
- Create a Spotinst Elastigroup if you do not have one already.
- In the Compute part select “HCS” as HealthCheck Type.
a. Go to your Elastigroup and click on Edit.
b. On the Compute tab, in the Launch Specification section, set the health check type to
HCSand update the group.
- Install the Spotinst
Health Check Serviceon of your instance within your secured VPC.
a. Choose one of your instances that will act as the
proxy, on which you should later install the docker.
b. Create a Security Group and attach it to the instance. This Security Group allows input traffic from Spotinst Health Check Service in
Port TCP 80for the Spotinst Whitelabeled IPs
c. SSH into your EC2 Instance and Install the Health Check service:
i. Install Docker first.
ii. Run the following command to pull the docker image
docker pull spotinst/healthcheck
iii. Run the following command to run the service:
docker run -d --restart=always -p 80:80 spotinst/healthcheck:latest
Alternatively, you can configure use the following userdata script to install docker and the HCS service.
#!/bin/bash sudo yum update -y sudo yum install -y docker sudo service docker start sudo usermod -a -G docker ec2-user sudo docker pull spotinst/healthcheck sudo docker run -d --restart=always -p 80:80 spotinst/healthcheck:latest
- Set the Health Check configuration in the Elastigroup.
a. Go to your Elastigroup and click on the “Actions” menu at the top left. Click on “Set Health Check” from the menu
b. Define the Health Check properties:Name: Name your Health Check for convenience.
ProxyAddress: The public host/IP of your selected instance you installed service on in
section 2. This will be set like http://publicip
Protocol: Which protocol will Spotinst use to check the healthiness of your instances. Supported for now are: http / https.
Endpoint: The path of the Health Check in each instance.
Interval: The interval (in seconds) between the checks. Minimum of 10.
Timeout: The timeout (in seconds) to wait for each instance to answer the check. If it did not answer, we mark this attempt as
UnhealthyThreshold: The number of consecutive failed health checks that must occur before declaring an instance
HealthyThreshold: The number of consecutive successful health checks that must occur before declaring an instance
You can do steps 3 and 4 via our API too. For more information go to Our API wiki.
Now – the health check is running, and Spotinst’s monitor service will send HCS requests according to the specified interval.
The healthiness should be available shortly through the Instances table list:
In case of an Instance failure – the HCS service will trigger a replacement operation to launch a new instance and terminate the unhealthy one.
That’s all for today!
The Spotinst Team.