Why We Connected Several PCs Instead of Buying One Bigger Machine

One machine could appear healthy until an interactive request arrived while a long batch job held memory. Adding another PC did not solve ownership, recovery, or knowledge-quality questions by itself.

The working rule for “The operating problem” is: One machine could appear healthy until an interactive request arrived while a long batch job held memory. Adding another PC did not solve ownership, recovery, or knowledge-quality questions by itself. Preserve timestamped state transitions, reason codes, and retry outcomes so that an operational decision can be reconstructed later.

For verification, save the model and runtime versions, source input, relevant settings, and observed output together. Repeat the step while changing only one factor, and record unexpected results and untested limits as carefully as successes before applying the guidance to private or production data.

We split the system into channel, control, worker, and knowledge planes. Channels format requests; a coordinator owns priority and leases; workers run models; verified artifacts enter the knowledge path.

The working rule for “The design decision” is: The minimum useful layout is one always-on coordinator and one worker. A missing worker must leave the request queued and explain why it cannot run. Preserve timestamped state transitions, reason codes, and retry outcomes so that an operational decision can be reconstructed later.

Preserve the before-and-after state and the time of the check so that another run can reproduce the result. Include at least one failure condition—such as empty input, constrained resources, or a restart—to reveal the boundary of the step rather than documenting only the happy path.

The minimum useful layout is one always-on coordinator and one worker. A missing worker must leave the request queued and explain why it cannot run.

The working rule for “How the mechanism works” is: This series documents the decisions, failures, tested boundaries, and unfinished parts rather than presenting a universal cluster product. Preserve timestamped state transitions, reason codes, and retry outcomes so that an operational decision can be reconstructed later.

Define completion with an observable result instead of a general impression. Repeat the same input, and if the output changes, isolate whether the model, runtime settings, or source data changed before moving to the next stage.

The starter coordinator has automated tests for priority, RAM gating, expired-job recovery, and rejection of late duplicate results. Runtime, sensor, and messaging adapters remain environment-specific.

The working rule for “What we verified” is: One machine could appear healthy until an interactive request arrived while a long batch job held memory. Adding another PC did not solve ownership, recovery, or knowledge-quality questions by itself. Preserve timestamped state transitions, reason codes, and retry outcomes so that an operational decision can be reconstructed later.

For verification, save the model and runtime versions, source input, relevant settings, and observed output together. Repeat the step while changing only one factor, and record unexpected results and untested limits as carefully as successes before applying the guidance to private or production data.

This series documents the decisions, failures, tested boundaries, and unfinished parts rather than presenting a universal cluster product.

The working rule for “Boundary and completion criteria” is: The minimum useful layout is one always-on coordinator and one worker. A missing worker must leave the request queued and explain why it cannot run. Preserve timestamped state transitions, reason codes, and retry outcomes so that an operational decision can be reconstructed later.

Preserve the before-and-after state and the time of the check so that another run can reproduce the result. Include at least one failure condition—such as empty input, constrained resources, or a restart—to reveal the boundary of the step rather than documenting only the happy path.