Armada

Armada is a system built on top of Kubernetes for running batch workloads. With Armada as middleware for batch, Kubernetes can be a common substrate for batch and service workloads. Armada is used in production and can run millions of jobs per day across tens of thousands of nodes.

Armada addresses the following limitations of Kubernetes:

1. Scaling a single Kubernetes cluster beyond a certain size is challenging. Hence, Armada is designed to effectively schedule jobs across many Kubernetes clusters. Many thousands of nodes can be managed by Armada in this way.
2. Achieving very high throughput using the in-cluster storage backend, etcd, is challenging. Hence, Armada performs queueing and scheduling out-of-cluster using a specialized storage layer. This allows Armada to maintain queues composed of millions of jobs.
3. The default kube-scheduler is not suitable for batch. Instead, Armada includes a novel multi-Kubernetes cluster scheduler with support for important batch scheduling features, such as:
   • Fair queuing and scheduling across multiple users. Based on dominant resource fairness.
   • Resource and job scheduling rate limits.
   • Gang-scheduling, i.e., atomically scheduling sets of related jobs.
   • Job preemption, both to run urgent jobs in a timely fashion and to balance resource allocation between users.

Armada also provides features to help manage large compute clusters effectively, including:

• Detailed analytics exposed via Prometheus showing how the system behaves and how resources are allocated.
• Automatically removing nodes exhibiting high failure rates from consideration for scheduling.
• A mechanism to earmark nodes for a particular set of jobs, but allowing them to be used by other jobs when not used for their primary purpose.

Armada is designed with the enterprise in mind; all components are secure and highly available.

Armada is a CNCF Sandbox project and is used in production at G-Research.

For an overview of Armada, see the following videos:

• Armada - high-throughput batch scheduling
• Building Armada - Running Batch Jobs at Massive Scale on Kubernetes

The Armada project adheres to the CNCF Code of Conduct.

Installation

Armada Operator

For installation instructions, easiest way is to use the Armada Operator. For more information, see the Armada Operator repository.

Alternatively, you can install Armada manually by using the Helm charts defined in the deployment directory.

armadactl

Armada also provides a command-line interface, armadactl, which can be used to interact with the Armada system.

To install armadactl, run the following script:

scripts/get-armadactl.sh

Or download it from the GitHub Release page for your platform.

Local Development

Local Development with Goreman

Goreman is a Go-based clone of Foreman that manages Procfile-based applications, allowing you to run multiple processes with a single command. Components are built from source and run on the host, so iteration is fast and debuggers attach directly.

Start Armada with one command:

mage dev:up                 # no-auth
mage dev:up auth            # OIDC via keycloak
mage dev:up fake-executor   # no Kubernetes cluster needed

mage dev:up installs goreman to ./bin/ if missing, brings up redis/postgres/pulsar via _local/compose/stack.yaml, runs _local/scripts/init.sh to create databases and apply migrations, then runs goreman with the chosen procfile in the foreground. Ctrl+C stops everything cleanly. Image versions for the dependencies can be overridden via REDIS_IMAGE, POSTGRES_IMAGE, PULSAR_IMAGE, KEYCLOAK_IMAGE.

To stop the dependency containers afterwards:

mage dev:down

Local Development with Authentication

mage dev:up auth brings up the auth flow: Keycloak is added to the dependency containers, the auth-flavoured procfile starts the components, and you can talk to Armada with OIDC:

armadactl --config _local/.armadactl.yaml --context auth-oidc get queues

Authentication Configuration

The auth profile configures:

• Keycloak: OIDC provider running on http://localhost:8180 with pre-configured realm, users, and clients
• Users: admin/admin (admin group), user/password (users group) for both OIDC and basic auth
• Service accounts: Executor and Scheduler use OIDC Client Credentials flow for service-to-service authentication
• APIs: Server, Lookout, and Binoculars APIs are secured with OIDC and basic auth
• Web UIs: Lookout UI uses OIDC for user authentication
• armadactl: Supports multiple authentication flows - OIDC PKCE flow (auth-oidc), OIDC Device flow (auth-oidc-device), OIDC Password flow (auth-oidc-password), and basic auth (auth-basic)

All components support both OIDC and basic auth for convenience.

Local Development with Fake Executor

For testing Armada without a real Kubernetes cluster, use the fake executor that simulates a Kubernetes environment:

mage dev:up fake-executor

The fake executor simulates:

• 2 virtual nodes with 8 CPUs and 32Gi memory each
• Pod lifecycle management without actual container execution
• Resource allocation and job state transitions

This is useful for:

• Testing Armada's scheduling logic
• Development when Kubernetes is not available
• Integration testing of job flows

Available Compose Profiles

The compose file _local/compose/stack.yaml supports two profiles:

For Apache Airflow, use the separate compose file: docker compose -f _local/airflow/docker-compose.yaml up -d.

Available Procfiles

All Procfiles are located in _local/procfiles/:

Restart individual processes with goreman restart <component> (e.g., goreman restart server).

Service Ports

Run goreman run status to check the status of the processes (running processes are prefixed with *):

$ goreman run status
*server
*scheduler
*scheduleringester
*eventingester
*executor
*lookout
*lookoutingester
*binoculars
*lookoutui

Goreman exposes services on the following ports:

Documentation

For documentation, see the following:

• Overview
• Getting Started
• Architecture
• User guide
• Development guide
• Release notes/Version history
• API Documentation

We expect readers of the documentation to have a basic understanding of Docker and Kubernetes; see, e.g., the following links:

• Docker overview
• Kubernetes overview

Contributions

Thank you for considering contributing to Armada! We want everyone to feel that they can contribute to the Armada Project. Your contributions are valuable, whether it's fixing a bug, implementing a new feature, improving documentation, or suggesting enhancements. We appreciate your time and effort in helping make this project better for everyone. For more information about contributing to Armada see CONTRIBUTING.md and before proceeding to contributions see CODE_OF_CONDUCT.md

Discussion

If you are interested in discussing Armada you can find us on