Troubleshoot Amazon AWS EKS deployment issues

Learn how you can troubleshoot various issues when you deploy MOSTLY AI to an AWS EKS cluster. Each of the listed issues includes a description of the problem and solution that shows how to overcome or workaround the issue.

AWS reports VcpuLimitExceeded


When the deployment script creates a new EC2 instance, you might see the error below.

Status Reason: Could not launch On-Demand Instances. VcpuLimitExceeded - You have
requested more vCPU capacity than your current vCPU limit of 32 allows for the
instance bucket that the specified instance type belongs to. 
Please visit to request an adjustment to
this limit. Launching EC2 instance failed.


You can workaround this issue in one of two ways.

  • Request VcpuLimitExceeded via (opens in a new tab)
  • Use smaller EC2 type instances. For example, m5.xlarge. Edit eks-cluster.yaml and define the instance type in the WorkerNodesInstanceType section.
        Type: String
        Description: EC2 instance type for the worker nodes
        Default: m5.xlarge

Region-specific EKS image


By default, the deployment script uses the Standard EKS-optimised AMIs in eu-central-1 AWS region. This is defined in the EksAmiIds section of the eks-cluster.yaml file

    # IDs of the "EKS-optimised AMIs" for the worker nodes:
    # IMPORTANT NOTE: Choose AWS EKS compatible ami IDs only for the region where you are creating the cluster and it's verion (1.27) in our case.
    # When ami ID found, update below with region and ami ID.
      Standard: ami-02ad6c39e1e54ebc8


If you are deploying the MOSTLY AI App in another AWS region different from eu-central-1, then you need to find the region-specific AWS AMI ID here: (opens in a new tab). To reflect this, add a new region and a standard AMI ID as shown in the line above in eks-cluster.yaml.