Memory ballooning with Edera

This guide provides an overview of how Edera manages memory ballooning, including its default settings, dynamic and static memory allocation modes, and manual adjustment options using the protect CLI. Whether you’re deploying Kubernetes workloads or specialized environments, this guide will help you optimize memory usage effectively.

• Default memory settings: Learn about Edera’s default max and target memory values and how to override them.
• Dynamic mode: Understand how memory is automatically adjusted based on usage.
• Static mode: Explore fixed memory allocation for advanced use cases.
• Manual adjustments: Use the protect CLI to fine-tune memory settings.
• Pod annotations: Simplify memory configuration directly in your Kubernetes manifests.

For a deeper dive into memory ballooning and advanced configurations, refer to our technical guide on memory ballooning.

Edera default memory settings

• Default max memory: 1024M
• Default target memory: 300M (also the minimum allowed)

Memory resource policy

Edera supports two memory allocation modes: dynamic (default) and static.

Dynamic mode (default)

In dynamic mode, memory is adjusted automatically between configured min and max values based on actual usage.

Pods can omit the annotation, or include:

dev.edera/resource-policy: "dynamic"

Maximum memory

• Calculated as the sum of all containers’ resources.requests.limits
• If unset, defaults to 1024M
• If below 300M, it is bumped to 300M

Dynamic memory behavior

• Allocation is recalculated at intervals based on actual process usage.
• If ≥90% of memory is unused → zone resizes to half
• If ≥70% of memory is used → memory is increased to:
  • The current maximum value, or
  • Current usage + 80MB

Check intervals

• Start at 100ms on pod start, settling to 2s checks
• Adjusts more aggressively on growth, less on shrink
• Eventually stabilizes to equal 2s intervals once usage plateaus

You can override the initial memory target using:

dev.edera/initial-memory-request: "<value in MB>"

Static mode (advanced use only)

Important

Static mode disables dynamic ballooning, which can:

• Lock in unused memory
• Prevent scaling memory up or down based on real usage
• Require restarts or manual intervention

Use static mode if:

• You’re running non-Kubernetes workloads
• You need predictable, fixed memory
• You’re tuning performance in specialized environments

Max / min / target memory

In static mode, memory is fixed at the configured value — min, max, and target are all set at launch and won’t change regardless of usage. The only way to modify them is by restarting the pod or using the protect CLI.

Use this annotation:

dev.edera/resource-policy: "static"

• All set to:
  • Container resources.requests.limits, or
  • dev.edera/memory annotation, or
  • Default of 1024M
• Any value below 300M will be reset to the default target

Manual memory adjustment with the protect CLI

# Switch between static and dynamic
protect zone update-resources <zone_name> --adjustment-policy static|dynamic

# Set target memory
protect zone update-resources <zone_name> --target-memory 500

# Set minimum memory
protect zone update-resources <zone_name> --min-memory 300

# Set maximum memory
protect zone update-resources <zone_name> --max-memory 700

Putting it all together

Apply the Edera RuntimeClass

kubectl apply -f runtime.yaml

runtime.yaml

apiVersion: node.k8s.io/v1
kind: RuntimeClass
metadata:
  name: edera
handler: edera

Verify it’s created:

kubectl get runtimeclass

Expected output:

NAME    HANDLER   AGE
edera   edera     1d

Deploy a pod with Edera

memory-pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: memory-test
spec:
  runtimeClassName: edera
  containers:
    - name: nginx
      image: nginx:1.25.3

Apply the pod:

kubectl apply -f memory-pod.yaml

Confirm pod is online:

watch kubectl get pods --all-namespaces --field-selector metadata.name=memory-test

Test with the protect CLI

Find the node:

kubectl get pods --all-namespaces -o json | jq -r '.items[] | select(.metadata.name == "memory-test") | .spec.nodeName + " " + .metadata.name'

SSH into the node and confirm the zone:

protect zone list

You should see something like:

┌────────────────────────────┬──────────────────────────────────────┬───────┬───────────────┬──────────────────────────────┐
│ name                       ┆ uuid                                 ┆ state ┆ ipv4          ┆ ipv6                         │
╞════════════════════════════╪══════════════════════════════════════╪═══════╪═══════════════╪══════════════════════════════╡
│ k8s_memory-hog_memory-test ┆ 08019dbc-efb9-49ac-aa45-f1b46dcccb3a ┆ ready ┆ 10.0.2.249/32 ┆ fe80::d882:bcff:fe45:cc5a/32 │
└────────────────────────────┴──────────────────────────────────────┴───────┴───────────────┴──────────────────────────────┘

Watch memory usage in a second terminal:

protect zone top

Update memory target to 4GB:

protect zone update-resources --target-memory 4096 k8s_memory-hog_memory-test

You’ll see something like:

┏━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Edera Protect ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃name                 id                   status               total memory        used memory          free memory         ┃
┃                                                                                                                            ┃
┃k8s_memory-hog_memor 08019dbc-efb9-49ac-a ready                3.9 GiB             159 MiB              3.8 GiB             ┃

Alternative: Use pod annotations

apiVersion: v1
kind: Pod
metadata:
  name: memory-test
  annotations:
    dev.edera/memory: "4096"
    dev.edera/resource-policy: "dynamic"
spec:
  runtimeClassName: edera
  containers:
    - name: nginx
      image: nginx:1.25.3

Additional notes

Tested with Edera 1.0.3-rc4