Evidence label: deterministic synthetic teaching model. This browser page executes a small JavaScript model of the stated policy. It does not run Java, access a JVM, create actual worker threads or contact a tool. Use it to understand the boundary and compare assumptions before running the separate Java example.
Predict the boundary before running the model
Predict the rejected count for a burst of twelve with four permits. Then set the dependency capacity to two without changing the permits. Explain why a semaphore can enforce the wrong limit perfectly.
Write a prediction for the terminal outcome, then use Run model. The summary reports the calculated end-state for the current inputs. The trace begins at its first event so you can inspect how that outcome is reached. Next event advances one row; Show complete trace exposes every row. Restart trace changes only the viewing position, not the selected inputs.
Run and inspect the synthetic experiment
Expected outcomes and useful counterexamples
Twelve submissions, four permits and dependency capacity four admit four and reject eight. Unrestricted mode admits twelve and marks eight as exceeding the declared dependency capacity.
Change one input, rerun and compare the exact values in the table. A boundary that still holds under the changed inputs is more informative than an attractive animation. Trace rows and text labels carry the result; the visual colors are supplementary. The model recalculates only after Run model, so an edited input does not silently replace the trace you are inspecting.
What this lab cannot establish
The burst is simultaneous and admitted calls remain active until submission ends. There is no waiting queue, fairness model, distributed limit, connection pool or actual Java scheduling. Dependency over-limit labels are model checks, not observed server errors.
The controls have intentionally small finite ranges. They are not operational recommendations. No output here demonstrates production capacity, a recommended heap size, successful cancellation of a remote effect or a GC performance improvement. Use the downloadable Java fixture and then a representative integration test to investigate those separate questions. Keep the runtime version and the measurement method with any real results.
Continue with the Java implementation
Bound Java Harness Fan-Out Before Virtual Threads Overload Tools contains the original Java fixture, the failure analysis and its primary references. Continue with Stop Java Harness Timeouts From Leaving Tool Work Running to examine the next ownership boundary. The examples have synthetic non-personal inputs and do not require an account, API key or external service.
All six guides and labs · Lab catalog.
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