f718c132b4
The volume watcher design was based on deploymentwatcher and drainer, but has an important difference: we don't want to maintain a goroutine for the lifetime of the volume. So we stop the volumewatcher goroutine for a volume when that volume has no more claims to free. But the shutdown races with updates on the parent goroutine, and it's possible to drop updates. Fortunately these updates are picked up on the next core GC job, but we're most likely to hit this race when we're replacing an allocation and that's the time we least want to wait. Wait until the volume has "settled" before stopping this goroutine so that the race between shutdown and the parent goroutine sending on `<-updateCh` is pushed to after the window we most care about quick freeing of claims. * Fixes a resource leak when volumewatchers are no longer needed. The volume is nil and can't ever be started again, so the volume's `watcher` should be removed from the top-level `Watcher`. * De-flakes the GC job test: the test throws an error because the claimed node doesn't exist and is unreachable. This flaked instead of failed because we didn't correctly wait for the first pass through the volumewatcher. Make the GC job wait for the volumewatcher to reach the quiescent timeout window state before running the GC eval under test, so that we're sure the GC job's work isn't being picked up by processing one of the earlier claims. Update the claims used so that we're sure the GC pass won't hit a node unpublish error. * Adds trace logging to unpublish operations
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://nomadproject.io
- Tutorials: HashiCorp Learn
- Forum: Discuss
- Mailing List: Google Groups
- Gitter: hashicorp-nomad
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 Learn: 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 Learn: Nomad Reference Architecture for recommended practices and a reference architecture for production deployments.
Documentation
Full, comprehensive documentation is available on the Nomad website: https://www.nomadproject.io/docs
Guides are available on HashiCorp Learn.
Contributing
See the contributing directory for more developer documentation.