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An operator designed to watch VPA objects and apply resources recommendations to Deployments and StatefulSets based on configurable annotations

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oblik

Oblik is a Kubernetes operator designed to apply Vertical Pod Autoscaler (VPA) resource recommendations to workloads such as Deployments, StatefulSets, DaemonSets, CronJobs, and CNPG Clusters. Oblik runs on a cron-like schedule and can be configured via annotations on the workloads. It also provides a CLI for manual operations and includes a mutating webhook to enforce default resources.

Oblik makes VPA compatible with HPA; you can use the Horizontal Pod Autoscaler (HPA) as before. Oblik only handles resource definitions automatically using VPA recommendations.

Summary

How it works

  • Automatic VPA Management: Oblik automatically creates, updates, and deletes VPA objects for enabled workloads.
  • Cron-like Scheduling: Oblik runs on a configurable cron schedule to apply VPA recommendations to workloads. You can specify the schedule using annotations on the workloads, and include random delays to stagger updates across your cluster.
  • Mutating Admission Webhook: Oblik includes a mutating admission webhook that enforces resource requests and limits default policies on initial deployment of workloads and use eventually available recommendations from VPA on deployment updates.

Usage

Minimal Tuning Example

Here is a minimal tuning example using commonly used options such as min-request-cpu and min-request-memory:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: minimal-app
  namespace: default
  labels:
    oblik.socialgouv.io/enabled: "true"
  annotations:
    oblik.socialgouv.io/min-request-cpu: "100m"
    oblik.socialgouv.io/min-request-memory: "128Mi"
spec:
  # Do not specify resources; let Oblik handle them
  containers:
    - name: app-container
      image: your-image

Example: Uncapping Minimum Memory Limit

If your application requires higher memory consumption during pod startup, you might need to uncap the min-limit-memory to a value higher than the request.

  • Using Hardcoded Value:

    oblik.socialgouv.io/min-limit-memory: "512Mi"

  • Using Calculator Algorithm:

    oblik.socialgouv.io/limit-memory-calculator-algo: "margin"
oblik.socialgouv.io/limit-memory-calculator-value: "256Mi"

Applying the Workload

Apply your workload manifest as usual:

kubectl apply -f your-deployment.yaml

Oblik will automatically create a corresponding VPA object and manage resource recommendations according to the configured cron schedule and annotations.

Features

  • Automatic VPA Management: Oblik automatically creates, updates, and deletes VPA objects for enabled workloads.
  • Applies VPA Recommendations: Automatically applies resource recommendations to workloads.
  • Configurable via Annotations: Customize behavior using annotations on workloads.
  • Supports CPU and Memory Recommendations: Adjust CPU and memory requests and limits.
  • Cron Scheduling with Random Delays: Schedule updates with optional random delays to stagger them, avoiding a pods restart dance.
  • Supported Workload Types:
    • Deployments
    • StatefulSets
    • DaemonSets
    • CronJobs
    • postgresql.cnpg.io/Cluster (see CNPG issue)
  • Customizable Algorithms: Use different algorithms and values for calculating resource adjustments.
  • Mutating Webhook: Enforces default resources on initial deployment and use recommendations if VPA exists.
  • Mattermost Webhook Notifications: Notify on resource updates (should also work with Slack but not actually tested).
  • CLI for Manual Operations: Provides a command-line interface for manual control.
  • High Availability: Minimizes the risk of the mutating webhook blocking deployments. Only the leader runs background cron resource updates to prevent conflicts.

Installation

You can deploy Oblik using the provided Helm chart:

git clone https://github.com/SocialGouv/oblik.git
cd oblik/charts/oblik
helm upgrade --install oblik . --namespace oblik

Alternatively, you can use the Docker image for the operator, and download the CLI binary from the GitHub releases.

Deploying Oblik with ArgoCD

If you're using ArgoCD to manage your Kubernetes deployments, to integrate the Oblik Helm chart you need to include specific settings in your ArgoCD Application resource.

Add the following sections to your ArgoCD Application spec:

spec:
  syncPolicy:
    syncOptions:
      - ApplyOutOfSyncOnly=true
      - RespectIgnoreDifferences=true
  ignoreDifferences:
    - group: admissionregistration.k8s.io
      kind: MutatingWebhookConfiguration
      name: oblik
      jsonPointers:
        - /webhooks/0/clientConfig/caBundle
    - group: ""
      kind: Secret
      name: webhook-certs
      jsonPointers:
        - /data

Requirements

  • Vertical Pod Autoscaler (VPA) Operator: Oblik requires the official Kubernetes VPA operator, which is not installed by default on Kubernetes clusters. You can find it here: Official Kubernetes VPA Operator

    • Note: You only need the VPA recommender component. The admission-controller and updater components are not required and can be omitted. This reduces the complexity and scalability issues of the VPA operator.

Configuration

To enable Oblik on a workload, you need to add a label to your workload object (e.g., Deployment, StatefulSet):

  • oblik.socialgouv.io/enabled: "true" or "false". Defaults to "false". Set to "true" to enable Oblik on the workload.

The operator uses annotations on workload objects to configure its behavior. All annotations should be prefixed with oblik.socialgouv.io/.

Annotations

Annotation Key (without prefix) Description Options Default
cron Cron expression to schedule when the recommendations are applied. Any valid cron expression "0 2 * * *"
cron-add-random-max Maximum random delay added to the cron schedule. Duration (e.g., "120m") "120m"
dry-run If set to "true", Oblik will simulate the updates without applying them. "true", "false" "false"
webhook-enabled Enable mutating webhook resources enforcement. "true", "false" "true"
request-cpu-apply-mode CPU request recommendation mode. "enforce", "off" "enforce"
request-memory-apply-mode Memory request recommendation mode. "enforce", "off" "enforce"
limit-cpu-apply-mode CPU limit apply mode. "enforce", "off" "enforce"
limit-memory-apply-mode Memory limit apply mode. "enforce", "off" "enforce"
limit-cpu-calculator-algo CPU limit calculator algorithm. "ratio", "margin" "ratio"
limit-memory-calculator-algo Memory limit calculator algorithm. "ratio", "margin" "ratio"
limit-cpu-calculator-value Value used by the CPU limit calculator algorithm. Any numeric value "1"
limit-memory-calculator-value Value used by the memory limit calculator algorithm. Any numeric value "1"
unprovided-apply-default-request-cpu Default CPU request if not provided by the VPA. "off", "minAllowed", "maxAllowed", or an arbitrary value (e.g., "100m") "off"
unprovided-apply-default-request-memory Default memory request if not provided by the VPA. "off", "minAllowed", "maxAllowed", or an arbitrary value (e.g., "128Mi") "off"
increase-request-cpu-algo Algorithm to increase CPU request. "ratio", "margin" "ratio"
increase-request-cpu-value Value used to increase CPU request. Any numeric value "1"
increase-request-memory-algo Algorithm to increase memory request. "ratio", "margin" "ratio"
increase-request-memory-value Value used to increase memory request. Any numeric value "1"
min-limit-cpu Minimum CPU limit value. Any valid CPU value (e.g., "200m") ""
max-limit-cpu Maximum CPU limit value. Any valid CPU value (e.g., "4") ""
min-limit-memory Minimum memory limit value. Any valid memory value (e.g., "200Mi") ""
max-limit-memory Maximum memory limit value. Any valid memory value (e.g., "8Gi") ""
min-request-cpu Minimum CPU request value. Any valid CPU value (e.g., "80m") ""
max-request-cpu Maximum CPU request value. Any valid CPU value (e.g., "8") ""
min-request-memory Minimum memory request value. Any valid memory value (e.g., "200Mi") ""
max-request-memory Maximum memory request value. Any valid memory value (e.g., "20Gi") ""
min-allowed-recommendation-cpu Minimum allowed CPU recommendation value. Overrides VPA minAllowed.cpu. Any valid CPU value ""
max-allowed-recommendation-cpu Maximum allowed CPU recommendation value. Overrides VPA maxAllowed.cpu. Any valid CPU value ""
min-allowed-recommendation-memory Minimum allowed memory recommendation value. Overrides VPA minAllowed.memory. Any valid memory value ""
max-allowed-recommendation-memory Maximum allowed memory recommendation value. Overrides VPA maxAllowed.memory. Any valid memory value ""
min-diff-cpu-request-algo Algorithm to calculate the minimum CPU request difference for applying recommendations. "ratio", "margin" "ratio"
min-diff-cpu-request-value Value used for minimum CPU request difference calculation. Any numeric value "0"
min-diff-memory-request-algo Algorithm to calculate the minimum memory request difference for applying recommendations. "ratio", "margin" "ratio"
min-diff-memory-request-value Value used for minimum memory request difference calculation. Any numeric value "0"
min-diff-cpu-limit-algo Algorithm to calculate the minimum CPU limit difference for applying recommendations. "ratio", "margin" "ratio"
min-diff-cpu-limit-value Value used for minimum CPU limit difference calculation. Any numeric value "0"
min-diff-memory-limit-algo Algorithm to calculate the minimum memory limit difference for applying recommendations. "ratio", "margin" "ratio"
min-diff-memory-limit-value Value used for minimum memory limit difference calculation. Any numeric value "0"
memory-request-from-cpu-enabled Calculate memory request from CPU request instead of recommendation. "true", "false" "false"
memory-limit-from-cpu-enabled Calculate memory limit from CPU limit instead of recommendation. "true", "false" "false"
memory-request-from-cpu-algo Algorithm to calculate memory request based on CPU request. "ratio", "margin" "ratio"
memory-request-from-cpu-value Value used for calculating memory request from CPU request. Any numeric value "2"
memory-limit-from-cpu-algo Algorithm to calculate memory limit based on CPU limit. "ratio", "margin" "ratio"
memory-limit-from-cpu-value Value used for calculating memory limit from CPU limit. Any numeric value "2"
request-apply-target Select which recommendation to apply by default on request. "frugal", "balanced", "peak" "balanced"
request-cpu-apply-target Select which recommendation to apply for CPU request. "frugal", "balanced", "peak" "balanced"
request-memory-apply-target Select which recommendation to apply for memory request. "frugal", "balanced", "peak" "balanced"
limit-apply-target Select which recommendation to apply by default on limit. "auto", "frugal", "balanced", "peak" "auto"
limit-cpu-apply-target Select which recommendation to apply for CPU limit. "auto", "frugal", "balanced", "peak" "auto"
limit-memory-apply-target Select which recommendation to apply for memory limit. "auto", "frugal", "balanced", "peak" "auto"
request-cpu-scale-direction Allowed scaling direction for CPU request. "both", "up", "down" "both"
request-memory-scale-direction Allowed scaling direction for memory request. "both", "up", "down" "both"
limit-cpu-scale-direction Allowed scaling direction for CPU limit. "both", "up", "down" "both"
limit-memory-scale-direction Allowed scaling direction for memory limit. "both", "up", "down" "both"

Targeting Specific Containers

To apply configurations to a specific container within a workload, suffix the annotation key with the container name, e.g.:

  • oblik.socialgouv.io/min-limit-memory.hasura: Sets the minimum memory limit for the container named hasura.

Recommendations:

  • Do not specify resource requests and limits in your workload manifest. Let Oblik handle them based on VPA recommendations and settings as oblik annotation and default settings on operator deployment.
  • The webhook will read the VPA if it exists and apply recommendations to the workload upon deployment.

Example

apiVersion: apps/v1
kind: Deployment
metadata:
  name: example-deployment
  namespace: default
  labels:
    oblik.socialgouv.io/enabled: "true"
  annotations:
    oblik.socialgouv.io/min-request-cpu: "100m"
    oblik.socialgouv.io/min-request-memory: "128Mi"
spec:
  # Do not specify resources; let Oblik handle them
  containers:
    - name: app-container
      image: your-image

Using the CLI

Oblik provides a CLI for manual operations. You can download the binary from the GitHub releases.

CLI Usage

  • Process all workloads in all namespaces:

    oblik --all

  • Process a specific workload:

    oblik --namespace my-ns --name example-deployment

  • Process workloads using selectors:

    oblik --namespace my-ns --selector foo=bar

  • Force Mode:

    Use the --force flag to run on workloads that do not have the oblik.socialgouv.io/enabled: "true" label.

    oblik --namespace my-ns --name example-deployment --force

Downloading the CLI

You can download the latest CLI binary from the GitHub releases.

Docker Image

The Docker image for the Oblik operator is available and can be used to run the operator in your Kubernetes cluster.

Environment Variable Description Options Default
OBLIK_DEFAULT_CRON Default cron expression for scheduling when the recommendations are applied. Any valid cron expression "0 2 * * *"
OBLIK_DEFAULT_CRON_ADD_RANDOM_MAX Maximum random delay added to the cron schedule. Duration (e.g., "120m") "120m"
OBLIK_DEFAULT_DRY_RUN If set to "true", Oblik will simulate the updates without applying them. "true", "false" "false"
OBLIK_DEFAULT_WEBHOOK_ENABLED Enable mutating webhook resources enforcement. "true", "false" "true"
OBLIK_DEFAULT_REQUEST_CPU_APPLY_MODE CPU request recommendation mode. "enforce", "off" "enforce"
OBLIK_DEFAULT_REQUEST_MEMORY_APPLY_MODE Memory request recommendation mode. "enforce", "off" "enforce"
OBLIK_DEFAULT_LIMIT_CPU_APPLY_MODE CPU limit apply mode. "enforce", "off" "enforce"
OBLIK_DEFAULT_LIMIT_MEMORY_APPLY_MODE Memory limit apply mode. "enforce", "off" "enforce"
OBLIK_DEFAULT_LIMIT_CPU_CALCULATOR_ALGO Algorithm to use for calculating CPU limits. "ratio", "margin" "ratio"
OBLIK_DEFAULT_LIMIT_MEMORY_CALCULATOR_ALGO Algorithm to use for calculating memory limits. "ratio", "margin" "ratio"
OBLIK_DEFAULT_LIMIT_CPU_CALCULATOR_VALUE Value to use with the CPU limit calculator algorithm. Any numeric value "1"
OBLIK_DEFAULT_LIMIT_MEMORY_CALCULATOR_VALUE Value to use with the memory limit calculator algorithm. Any numeric value "1"
OBLIK_DEFAULT_UNPROVIDED_APPLY_DEFAULT_REQUEST_CPU Default behavior for CPU requests if not provided. "off", "minAllowed", "maxAllowed", or value (e.g., "100m") "off"
OBLIK_DEFAULT_UNPROVIDED_APPLY_DEFAULT_REQUEST_MEMORY Default behavior for memory requests if not provided. "off", "minAllowed", "maxAllowed", or value (e.g., "128Mi") "off"
OBLIK_DEFAULT_INCREASE_REQUEST_CPU_ALGO Algorithm to use for increasing CPU requests. "ratio", "margin" "ratio"
OBLIK_DEFAULT_INCREASE_REQUEST_CPU_VALUE Value to use with the algorithm for increasing CPU requests. Any numeric value "1"
OBLIK_DEFAULT_INCREASE_REQUEST_MEMORY_ALGO Algorithm to use for increasing memory requests. "ratio", "margin" "ratio"
OBLIK_DEFAULT_INCREASE_REQUEST_MEMORY_VALUE Value to use with the algorithm for increasing memory requests. Any numeric value "1"
OBLIK_DEFAULT_MIN_LIMIT_CPU Value used to cap minimum CPU limit. Any valid CPU value (e.g., "200m") ""
OBLIK_DEFAULT_MAX_LIMIT_CPU Value used to cap maximum CPU limit. Any valid CPU value (e.g., "4") ""
OBLIK_DEFAULT_MIN_LIMIT_MEMORY Value used to cap minimum memory limit. Any valid memory value (e.g., "200Mi") ""
OBLIK_DEFAULT_MAX_LIMIT_MEMORY Value used to cap maximum memory limit. Any valid memory value (e.g., "8Gi") ""
OBLIK_DEFAULT_MIN_REQUEST_CPU Value used to cap minimum CPU request. Any valid CPU value (e.g., "80m") ""
OBLIK_DEFAULT_MAX_REQUEST_CPU Value used to cap maximum CPU request. Any valid CPU value (e.g., "8") ""
OBLIK_DEFAULT_MIN_REQUEST_MEMORY Value used to cap minimum memory request. Any valid memory value (e.g., "200Mi") ""
OBLIK_DEFAULT_MAX_REQUEST_MEMORY Value used to cap maximum memory request. Any valid memory value (e.g., "20Gi") ""
OBLIK_DEFAULT_MIN_ALLOWED_RECOMMENDATION_CPU Minimum allowed CPU recommendation value. Overrides VPA minAllowed.cpu. Any valid CPU value ""
OBLIK_DEFAULT_MAX_ALLOWED_RECOMMENDATION_CPU Maximum allowed CPU recommendation value. Overrides VPA maxAllowed.cpu. Any valid CPU value ""
OBLIK_DEFAULT_MIN_ALLOWED_RECOMMENDATION_MEMORY Minimum allowed memory recommendation value. Overrides VPA minAllowed.memory. Any valid memory value ""
OBLIK_DEFAULT_MAX_ALLOWED_RECOMMENDATION_MEMORY Maximum allowed memory recommendation value. Overrides VPA maxAllowed.memory. Any valid memory value ""
OBLIK_DEFAULT_MIN_DIFF_CPU_REQUEST_ALGO Algorithm to calculate the minimum CPU request difference for applying recommendations. "ratio", "margin" "ratio"
OBLIK_DEFAULT_MIN_DIFF_CPU_REQUEST_VALUE Value used for minimum CPU request difference calculation. Any numeric value "0"
OBLIK_DEFAULT_MIN_DIFF_MEMORY_REQUEST_ALGO Algorithm to calculate the minimum memory request difference for applying recommendations. "ratio", "margin" "ratio"
OBLIK_DEFAULT_MIN_DIFF_MEMORY_REQUEST_VALUE Value used for minimum memory request difference calculation. Any numeric value "0"
OBLIK_DEFAULT_MIN_DIFF_CPU_LIMIT_ALGO Algorithm to calculate the minimum CPU limit difference for applying recommendations. "ratio", "margin" "ratio"
OBLIK_DEFAULT_MIN_DIFF_CPU_LIMIT_VALUE Value used for minimum CPU limit difference calculation. Any numeric value "0"
OBLIK_DEFAULT_MIN_DIFF_MEMORY_LIMIT_ALGO Algorithm to calculate the minimum memory limit difference for applying recommendations. "ratio", "margin" "ratio"
OBLIK_DEFAULT_MIN_DIFF_MEMORY_LIMIT_VALUE Value used for minimum memory limit difference calculation. Any numeric value "0"
OBLIK_DEFAULT_MEMORY_REQUEST_FROM_CPU_ENABLED Calculate memory request from CPU request instead of recommendation. "true", "false" "false"
OBLIK_DEFAULT_MEMORY_LIMIT_FROM_CPU_ENABLED Calculate memory limit from CPU limit instead of recommendation. "true", "false" "false"
OBLIK_DEFAULT_MEMORY_REQUEST_FROM_CPU_ALGO Algorithm to calculate memory request based on CPU request. "ratio", "margin" "ratio"
OBLIK_DEFAULT_MEMORY_REQUEST_FROM_CPU_VALUE Value used for calculating memory request from CPU request. Any numeric value "2"
OBLIK_DEFAULT_MEMORY_LIMIT_FROM_CPU_ALGO Algorithm to calculate memory limit based on CPU limit. "ratio", "margin" "ratio"
OBLIK_DEFAULT_MEMORY_LIMIT_FROM_CPU_VALUE Value used for calculating memory limit from CPU limit. Any numeric value "2"
OBLIK_DEFAULT_REQUEST_APPLY_TARGET Select which recommendation to apply by default on request. "frugal", "balanced", "peak" "balanced"
OBLIK_DEFAULT_REQUEST_CPU_APPLY_TARGET Select which recommendation to apply for CPU request. "frugal", "balanced", "peak" "balanced"
OBLIK_DEFAULT_REQUEST_MEMORY_APPLY_TARGET Select which recommendation to apply for memory request. "frugal", "balanced", "peak" "balanced"
OBLIK_DEFAULT_LIMIT_APPLY_TARGET Select which recommendation to apply by default on limit. "auto", "frugal", "balanced", "peak" "auto"
OBLIK_DEFAULT_LIMIT_CPU_APPLY_TARGET Select which recommendation to apply for CPU limit. "auto", "frugal", "balanced", "peak" "auto"
OBLIK_DEFAULT_LIMIT_MEMORY_APPLY_TARGET Select which recommendation to apply for memory limit. "auto", "frugal", "balanced", "peak" "auto"
OBLIK_DEFAULT_REQUEST_CPU_SCALE_DIRECTION Allowed scaling direction for CPU request. "both", "up", "down" "both"
OBLIK_DEFAULT_REQUEST_MEMORY_SCALE_DIRECTION Allowed scaling direction for memory request. "both", "up", "down" "both"
OBLIK_DEFAULT_LIMIT_CPU_SCALE_DIRECTION Allowed scaling direction for CPU limit. "both", "up", "down" "both"
OBLIK_DEFAULT_LIMIT_MEMORY_SCALE_DIRECTION Allowed scaling direction for memory limit. "both", "up", "down" "both"
OBLIK_MATTERMOST_WEBHOOK_URL Webhook URL for Mattermost notifications. URL ""

Notes:

  • Algorithms: The options "ratio" and "margin" refer to how values are calculated:

    • ratio: Multiplies the base value by a ratio (e.g., value = base * ratio).
    • margin: Adds a fixed margin to the base value (e.g., value = base + margin).

  • Scaling Directions: The scaling direction options control whether resources can be increased, decreased, or both when applying recommendations:

    • both: Allows both scaling up and down.
    • up: Only allows scaling up (increasing resources).
    • down: Only allows scaling down (decreasing resources).

  • Apply Modes:

    • enforce: Oblik will enforce the recommended values.
    • off: Oblik will not apply recommendations for this resource.

  • Apply Targets:

    • frugal: Use the lower bound of recommendations.
    • balanced: Use the middle value of recommendations.
    • peak: Use the upper bound of recommendations.
    • auto: Oblik will decide the best target based on other settings.

  • Unprovided Defaults:

    • off: Do not apply a default if the recommendation is missing.
    • minAllowed/maxAllowed: Use the VPA's minAllowed or maxAllowed values.
    • Specific Value: Provide a specific value to use as the default.

Feel free to set these environment variables in your operator's deployment manifest to establish cluster-wide defaults. Individual workloads can override these defaults by specifying annotations on their resource definitions.

Limitations and overcoming them

VPA Recommendations for Certain Workloads

The Vertical Pod Autoscaler (VPA) may not provide accurate memory recommendations for specific workloads, such as Java Virtual Machines (JVM) and PostgreSQL databases. These applications manage their own memory usage internally, which can lead to discrepancies in VPA's memory suggestions.

Recommended Configurations

For workloads where VPA's memory recommendations are unreliable, consider the following two options:

1. Manually Set Memory Requests

Disable VPA’s automatic memory management and manually configure memory resources to suit your application’s needs.

Steps:

  1. Disable VPA Memory Handling:
    • Set the oblik.socialgouv.io/request-memory-apply-mode annotation to "off" in your deployment.
  2. Manually Configure Memory Resources:
    • Define memory requests and limits directly within your deployment specification.

Example:

metadata:
  annotations:
    oblik.socialgouv.io/request-memory-apply-mode: "off"
spec:
  containers:
    - name: jvm-container
      image: your-jvm-image:latest
      resources:
        requests:
          memory: "3Gi"  # Manually set based on application requirements
      ports:
        - containerPort: 8080
2. Calculate Memory Based on CPU Usage Recommendations

Leverage the relationship between CPU and memory usage to derive memory allocations from CPU recommendations. This method is particularly effective for applications like PostgreSQL, where a typical memory-to-CPU ratio is well-established.

Example Ratio:

  • PostgreSQL: For every 1 CPU, allocate approximately 4 GB of memory.

Steps:

  1. Enable Memory Calculation from CPU:

    • Set oblik.socialgouv.io/memory-request-from-cpu-enabled to "true".

  2. Specify the Calculation Algorithm and Ratio:

    • Use memory-request-from-cpu-algo set to "ratio".
    • Define the ratio with memory-request-from-cpu-value. For instance, a value of "4" implies 4 GB of memory per CPU.

Example:

metadata:
  annotations:
    oblik.socialgouv.io/memory-request-from-cpu-enabled: "true"
    oblik.socialgouv.io/memory-request-from-cpu-algo: "ratio"
    oblik.socialgouv.io/memory-request-from-cpu-value: "4"

Example Configuration for a JVM Application

Below is an example YAML configuration for deploying a JVM application using CPU-based memory calculation:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: jvm-app
  namespace: default
  labels:
    oblik.socialgouv.io/enabled: "true"
  annotations:
    oblik.socialgouv.io/memory-request-from-cpu-enabled: "true"
    oblik.socialgouv.io/memory-request-from-cpu-algo: "ratio"
    oblik.socialgouv.io/memory-request-from-cpu-value: "2"
spec:
  replicas: 3
  selector:
    matchLabels:
      app: jvm-app
  template:
    metadata:
      labels:
        app: jvm-app
    spec:
      containers:
        - name: jvm-container
          image: your-jvm-image:latest
          resources:
            requests:
              cpu: "1"
              memory: "2Gi"  # Derived from CPU usage (1 CPU * 2 GB)
            limits:
              cpu: "2"
              memory: "4Gi"
          ports:
            - containerPort: 8080

Explanation:

  • Annotations:

    • memory-request-from-cpu-enabled: "true": Enables memory calculation based on CPU usage.
    • memory-request-from-cpu-algo: "ratio": Specifies that a fixed ratio will be used for calculation.
    • memory-request-from-cpu-value: "2": Sets the memory allocation to 2 GB per CPU.

  • Resources:

    • Requests:
      • cpu: "1": Requests 1 CPU.
      • memory: "2Gi": Allocates 2 GB of memory based on the ratio (1 CPU * 2 GB).
    • Limits:
      • cpu: "2": Limits the container to 2 CPUs.
      • memory: "4Gi": Limits the memory usage to 4 GB.

VPA Metrics Collection Period

The VPA bases its recommendations on the last 8 days of Prometheus metrics. If your workload has irregular loads with intervals longer than this 8-day period, the VPA (and thus Oblik) may not provide relevant recommendations for these workloads.

For workloads with irregular patterns beyond the 8-day window, consider manually managing resource requests and limits or using alternative scaling strategies.

High Resource Usage at Pod Startup

Some applications may have high CPU or memory usage during pod startup, which can cause issues with readiness and startup probes.

Solutions

  • Adjust Startup Probes: Increase the initial delay or timeout for startup and readiness probes to accommodate the higher resource usage at startup.

  • Increase Resource Limits or Recommendations: Increase the CPU and memory limits or recommendations to provide more resources during startup.

Example: Uncapping Minimum Memory Limit

If your application requires higher memory consumption during pod startup, you might need to uncap the min-limit-memory to a value higher than the request.

  • Using Hardcoded Value:

    oblik.socialgouv.io/min-limit-memory: "512Mi"

  • Using Calculator Algorithm:

    oblik.socialgouv.io/limit-memory-calculator-algo: "margin"
oblik.socialgouv.io/limit-memory-calculator-value: "256Mi"

Adjusting Probes

spec:
  containers:
    - name: app-container
      image: your-image
      readinessProbe:
        initialDelaySeconds: 30
        timeoutSeconds: 5
      startupProbe:
        initialDelaySeconds: 60
        timeoutSeconds: 10

Running Tests

The Oblik project includes end-to-end tests that can be run to verify the functionality of the operator. These tests are located in the tests directory and are implemented using Go's testing framework.

To run all tests, use the following command from the root of the project:

go test ./tests -v

Running Specific Tests

You can run a specific test case by using the -test-case flag. This flag allows you to specify the name of a single test case to run, which is particularly useful when debugging or focusing on a particular feature.

To run a specific test, use the following command:

go test ./tests -v -test-case=TestCaseName

Replace TestCaseName with the name of the test case you want to run. For example, to run the "TestOffRecommendations" test case:

go test ./tests -v -test-case=TestOffRecommendations

This will run only the specified test case, allowing for faster and more focused testing during development or debugging.

Contributing

We welcome contributions! Please feel free to submit pull requests or open issues on our GitHub repository.

Related Projects and Resources

Additional Resources

License

This project is licensed under the MIT License - see the LICENSE file for details.

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An operator designed to watch VPA objects and apply resources recommendations to Deployments and StatefulSets based on configurable annotations

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