FinTech - Global latency sensitive service on EKS

Background of the service

• A global latency sensitive service is running on AWS across multiple regions.
• Some components are stateful. We make sure the stateful components have a backup node which can take over the workload when there is a failure .
• Some components have long-lived TCP connection. We need to gracefully close the connection before we do release.
• To reduce the latency as much as possible, we deploy our services in six regions.

Architecture for a latency sensitive service.

Route 53 Traffic Policy

Traffic policy provides geo-based DNS resolution. This can be useful to route traffic between different cloud providers.

Global Accelerator

[Endpoint group] provides a entrypoint for your service in specific AWS region. You can route traffic between different AWS regions.

Data Layer

In general use case, we can put the database in the same region with the service to have the lowest latency. But, this results you need to have a application to aggregate the data from many databases in order to present the aggregated data for users.

How do we deploy services in EKS?

• Used StatefulSet for stateful components. Also, some components have a MySQL sidecar container, it needs volumeClaimTemplates to help it persist the data.
• Used EKS to serve components with large disk volume. We need to use AWS Backup service to make sure the data in the EBS volume has a daily snapshot.
• Used EKS with EFS to share disk between specific services. For example, a service A will parse the logs generated by service B. In this case, we use EFS to share logs file between service A and service B.

apiVersion: helm.fluxcd.io/v1
kind: HelmRelease
metadata:
  name: example-app
  namespace: app
  annotations:
    fluxcd.io/automated: "true"
spec:
  releaseName: example-app
  chart:
    git: ssh://git@github.com/my-org/helm-charts
    ref: app_1.0.0
    path: charts/app
  values:
    image:
      repository: xxxxxxxxxxx.dkr.ecr.ap-northeast-1.amazonaws.com/app
      tag: "xxxxxxxxxxxxxxxxxxxxxx"
    targetgroupbinding:
      ... truncated ...
    serviceAccount:
      enabled: true
      irsaRoleArn: "arn:aws:iam::xxxxxxxxxxxxx:role/app_irsa_role"
    configuration:
      environment: "prod" <- use variables to retrieve specific configs
      region: "frankfurt"

This is an example for deploying an service in EKS across many regions.
The helm chart covers all the details and let you easily scale your service.