How to Adjust Memory and CPU of Connect-inject Pods in Consul K8s – HashiCorp Help Center

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Introduction

This is a guide to demonstrate how to increase CPU and memory resources in connect-inject pods. The initial Helm chart defaults for the Consul containers are a bare minimum requirement to get Consul containers up and running for a multitude of environments, and Kubernetes resource tuning may be necessary to better suit your environment's needs as seen below.

Expected Outcome

Increasing the default resource of Consul connect-inject pod will provide faster service registration and discovery times in the Envoy sidecar.

Prerequisites

Administrative privileges in K8s namespace for Consul
Make sure connect-inject enabled
- For additional information review How does Consul Service Mesh Work on Kubernetes?

Use Case

In the event, there are high delays during Envoy service registration and discovery, and if any performance increase is to occur, the resources allocated to this component should help improve your case.

Procedure

Below are two types of procedures to adjust Memory and CPU on connect-inject pods.

Adjust the CPU/memory on the connect-inject deployment replicaSet

Get the connect-inject deployment.

$ kubectl get deployment consul-connect-injector -n consul
NAME                     READY UP-TO-DATE AVAILABLE AGE
consul-connect-injector   1/1      1        1       47m

Edit the consul-connect-injector deployment.

$ kubectl edit deployment consul-connect-injector -n consul

Adjust "resources" for cpu and memory to desired limits. Increments of 50 are acceptable.
```
resources:
limits:
cpu: 200m
memory: 150Mi
requests:
cpu: 100m
memory: 100Mi
```
Save the file and run the command to see the new connect-inject pod coming up with desired resources.
```
kubectl get pods -n consul
```

Adjust the CPU/memory on the connect-inject pod using the helm upgrade command

Create a values.yaml file with desired CPU/Memory values using your favorite editor e.g VIM.

connectInject:
  enabled: true
  resources:
    requests:
      memory: "100Mi"
      cpu: "100m"
    limits:
      memory: "150Mi"
      cpu: "200m"

Use the helm command to upgrade with new values with your consul-k8s version.

helm upgrade consul hashicorp/consul -n consul -f values.yaml --version '1.1.0'

Run the command to see the new connect-inject pod coming up with desired resources.
```
kubectl get pods -n consul
```

Additionally, we can increase metrics for sidecarProxy and Connect injected init container with helm upgrade command using the below yaml.

connectInject:
  initContainer:
    resources:
      requests:
        memory: "150Mi"
        cpu: "150m"
      limits:
        memory: "200Mi"
        cpu: "200m"
  sidecarProxy: #specific to envoy sidecars when scaling
    resources:
      requests:
        memory: "100Mi"
        cpu: "100m"
      limits:
        memory: "100Mi"
        cpu: "100m"

More information about these metrics can be found in the following article: Service Mesh Registration Time Tuning - Consul K8s Control Plane Resources.

References

Kubernetes site for kubectl edit
Service Mesh Registration Time Tuning - Consul K8s Control Plane Resources