2c4be7fc2e
Refactors of the `computeGroup` code in the reconciler to make understanding its mutations more manageable. Some of this work makes mutation more consistent but more importantly it's intended to make it readily _detectable_ while still being readable. Includes: * In the `computeCanaries` function, we mutate the dstate and the result and then the return values are used to further mutate the result in the caller. Move all this mutation into the function. * In the `computeMigrations` function, we mutate the result and then the return values are used to further mutate the result in the caller. Move all this mutation into the function. * In the `cancelUnneededCanaries` function, we mutate the result and then the return values are used to further mutate the result in the caller. Move all this mutation into the function, and annotate which `allocSet`s are mutated by taking a pointer to the set. * The `createRescheduleLaterEvals` function currently mutates the results and returns updates to mutate the results in the caller. Move all this mutation into the function to help cleanup `computeGroup`. * Extract `computeReconnecting` method from `computeGroup`. There's some tangled logic in `computeGroup` for determining changes to make for reconnecting allocations. Pull this out into its own function. Annotate mutability in the function by passing pointers to `allocSet` where needed, and mutate the result to update counts. Rename the old `computeReconnecting` method to `appendReconnectingUpdates` to mirror the naming of the similar logic for disconnects. * Extract `computeDisconnecting` method from `computeGroup`. There's some tangled logic in `computeGroup` for determining changes to make for disconnected allocations. Pull this out into its own function. Annotate mutability in the function by passing pointers to `allocSet` where needed, and mutate the result to update counts. * The `appendUnknownDisconnectingUpdates` method used to create updates for disconnected allocations mutates one of its `allocSet` arguments to change the allocations that the reschedule now set points to. Pull this update out into the caller. * A handful of small docstring and helper function fixes Ref: https://hashicorp.atlassian.net/browse/NMD-819
Nomad
Nomad is a simple and flexible workload orchestrator to deploy and manage containers (docker, podman), non-containerized applications (executable, Java), and virtual machines (qemu) across on-prem and clouds at scale.
Nomad is supported on Linux, Windows, and macOS. A commercial version of Nomad, Nomad Enterprise, is also available.
- Website: https://developer.hashicorp.com/nomad
- Tutorials: HashiCorp Developer
- Forum: Discuss
Nomad provides several key features:
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Deploy Containers and Legacy Applications: Nomad’s flexibility as an orchestrator enables an organization to run containers, legacy, and batch applications together on the same infrastructure. Nomad brings core orchestration benefits to legacy applications without needing to containerize via pluggable task drivers.
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Simple & Reliable: Nomad runs as a single binary and is entirely self contained - combining resource management and scheduling into a single system. Nomad does not require any external services for storage or coordination. Nomad automatically handles application, node, and driver failures. Nomad is distributed and resilient, using leader election and state replication to provide high availability in the event of failures.
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Device Plugins & GPU Support: Nomad offers built-in support for GPU workloads such as machine learning (ML) and artificial intelligence (AI). Nomad uses device plugins to automatically detect and utilize resources from hardware devices such as GPU, FPGAs, and TPUs.
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Federation for Multi-Region, Multi-Cloud: Nomad was designed to support infrastructure at a global scale. Nomad supports federation out-of-the-box and can deploy applications across multiple regions and clouds.
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Proven Scalability: Nomad is optimistically concurrent, which increases throughput and reduces latency for workloads. Nomad has been proven to scale to clusters of 10K+ nodes in real-world production environments.
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HashiCorp Ecosystem: Nomad integrates seamlessly with Terraform, Consul, Vault for provisioning, service discovery, and secrets management.
Quick Start
Testing
See Developer: Getting Started for instructions on setting up a local Nomad cluster for non-production use.
Optionally, find Terraform manifests for bringing up a development Nomad cluster on a public cloud in the terraform directory.
Production
See Developer: Nomad Reference Architecture for recommended practices and a reference architecture for production deployments.
Documentation
Full, comprehensive documentation is available on the Nomad website: https://developer.hashicorp.com/nomad/docs
Guides are available on HashiCorp Developer.
Roadmap
A timeline of major features expected for the next release or two can be found in the Public Roadmap.
This roadmap is a best guess at any given point, and both release dates and projects in each release are subject to change. Do not take any of these items as commitments, especially ones later than one major release away.
Contributing
See the contributing directory for more developer documentation.