Scheduler as Orchestrator

The core reframe for running a Compose stack on HPC: the scheduler allocation replaces Compose as the orchestration boundary.

Type: conceptual · Time: 20 minutes

Before you run this module

What you will learn

Prerequisites

Why the scheduler becomes the orchestrator

A laptop Compose stack uses one tool to start services, connect them, and manage their lifetime. On shared HPC, one scheduler allocation becomes that boundary. A launch script starts each component as a tracked step, uses a rootless runtime, keeps writable state in approved storage, and verifies results before the allocation ends.

Map each responsibility

Scroll horizontally to view all table columns.

Compose concept Scheduler-managed HPC mapping Decision to make
service tracked step inside one allocation Which process coordinates, and which processes are workers?
image or build immutable image launched by a rootless runtime Who builds and approves the image?
dependency or health check bounded semantic readiness gate What response proves the coordinator is ready?
volume explicit job-scoped scratch or approved storage bind Which state is temporary, and which must persist?
port loopback or a center-approved access path Who needs access, and what does policy permit?
device request scheduler CPU, memory, wall-time, or accelerator request Which resources must be requested before launch?

Make the local decisions

For one workflow, assign allocation, startup order, runtime state, access, and accelerator ownership to scheduler policy, runtime behavior, launch-script logic, or local-center configuration. The completion exercise below turns those assignments into a reviewable decision record.

Limitations

This mapping does not make a workflow portable unchanged. Scheduler syntax, network policy, storage, security controls, runtime modules, and accelerator flags vary by center. Multi-node discovery, persistent databases, privileged ports, and production availability are outside the single-node baseline.

Next step

Continue to Baseline Pattern: Single-Node Service + Workers to run the bounded shape, or check your center before execution.

Complete the decision exercise

Choose one local Compose stack and record who should own allocation, startup order, runtime state, access, and accelerators on your center.

Repository

Sources and scope

Review source roles and citations
  • SOW commitment: Publish the scheduler-as-orchestrator learning module. Fellowship SOW, Milestone 1
  • Project decision: Use one allocation as the bounded baseline orchestration boundary. Milestone 1 architecture

Project-adopted practices and project decisions are not BSSw Fellowship Program requirements.