FA-1101 / Workflow orchestration / Open access

Start a durable workflow execution: A duplicate start creates a second active execution · case 01

The workflow start operation is admitted even though a duplicate start creates a second active execution.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The admission path omits the execution unique invariant while validating the other operation preconditions.

THE FAILURE

The admission path omits the execution unique invariant while validating the other operation preconditions.

Unsuccessful approach: Adding the execution unique check repairs the reported defect, but replacing the adjacent version available check loses that independent invariant.

Case contract

Return a Boolean admission decision for start a durable workflow execution. The record r must satisfy all of: r['execution_unique'][0] not in r['execution_unique'][1]; r['version_available'][0] in r['version_available'][1]; set(r['input_required'][0]) <= set(r['input_required'][1]); r['parent_live'] == 'running'; r['start_deadline'][0] < r['start_deadline'][1]. Extra tracing fields are ignored; validation does not mutate the record.

Why this case matters

A deterministic local contract for workflow orchestration. Each negative fixture violates exactly one invariant. No transport timing, persistence, cryptographic verification, or full protocol implementation is claimed.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(r):
    return (r['version_available'][0] in r['version_available'][1]) and (set(r['input_required'][0]) <= set(r['input_required'][1])) and (r['parent_live'] == 'running') and (r['start_deadline'][0] < r['start_deadline'][1])
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
r = {'execution_unique': ['e2', ['e1']], 'version_available': [3, [2, 3]], 'input_required': [['order'], ['order', 'note']], 'parent_live': 'running', 'start_deadline': [10, 11]}
check('valid operation', solve(r), True)
check('A duplicate start creates a second active execution', solve(dict(r, **{'execution_unique': ['e1', ['e1']]})), False)
check('The workflow starts on an unavailable definition version', solve(dict(r, **{'version_available': [4, [2, 3]]})), False)
check('A workflow starts without its required input fields', solve(dict(r, **{'input_required': [['order'], ['note']]})), False)
check('A child starts after its parent was cancelled', solve(dict(r, **{'parent_live': 'cancelled'})), False)
check('A deferred start begins beyond the workflow start deadline', solve(dict(r, **{'start_deadline': [11, 11]})), False)
check('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)
check('repeat validation is pure', solve(r), True)
invalid = {'execution_unique': ['e1', ['e1']], 'version_available': [4, [2, 3]], 'input_required': [['order'], ['note']], 'parent_live': 'cancelled', 'start_deadline': [11, 11]}
keys = list(invalid)
pair = {keys[N % len(keys)]: invalid[keys[N % len(keys)]], keys[(N+1) % len(keys)]: invalid[keys[(N+1) % len(keys)]]}
check('two independent violations in variant', solve(dict(r, **pair)), False)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
valid operation	`True`	`True`	Passed
A duplicate start creates a second active execution	`True`	`False`	Failed
The workflow starts on an unavailable definition version	`False`	`False`	Passed
A workflow starts without its required input fields	`False`	`False`	Passed
A child starts after its parent was cancelled	`False`	`False`	Passed
A deferred start begins beyond the workflow start deadline	`False`	`False`	Passed
unrelated tracing metadata	`True`	`True`	Passed
repeat validation is pure	`True`	`True`	Passed
two independent violations in variant	`False`	`False`	Passed

SHA-256 / 3a54fe374fee307cadae2b42ea8492d6fe7a24a41486c47c1873a63826a1d40c

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(r):
    return (r['execution_unique'][0] not in r['execution_unique'][1]) and (set(r['input_required'][0]) <= set(r['input_required'][1])) and (r['parent_live'] == 'running') and (r['start_deadline'][0] < r['start_deadline'][1])
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
r = {'execution_unique': ['e2', ['e1']], 'version_available': [3, [2, 3]], 'input_required': [['order'], ['order', 'note']], 'parent_live': 'running', 'start_deadline': [10, 11]}
check('valid operation', solve(r), True)
check('A duplicate start creates a second active execution', solve(dict(r, **{'execution_unique': ['e1', ['e1']]})), False)
check('The workflow starts on an unavailable definition version', solve(dict(r, **{'version_available': [4, [2, 3]]})), False)
check('A workflow starts without its required input fields', solve(dict(r, **{'input_required': [['order'], ['note']]})), False)
check('A child starts after its parent was cancelled', solve(dict(r, **{'parent_live': 'cancelled'})), False)
check('A deferred start begins beyond the workflow start deadline', solve(dict(r, **{'start_deadline': [11, 11]})), False)
check('unrelated tracing metadata', solve(dict(r, trace='run-'+str(N))), True)
check('repeat validation is pure', solve(r), True)
invalid = {'execution_unique': ['e1', ['e1']], 'version_available': [4, [2, 3]], 'input_required': [['order'], ['note']], 'parent_live': 'cancelled', 'start_deadline': [11, 11]}
keys = list(invalid)
pair = {keys[N % len(keys)]: invalid[keys[N % len(keys)]], keys[(N+1) % len(keys)]: invalid[keys[(N+1) % len(keys)]]}
check('two independent violations in variant', solve(dict(r, **pair)), False)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
valid operation	`True`	`True`	Passed
A duplicate start creates a second active execution	`False`	`False`	Passed
The workflow starts on an unavailable definition version	`True`	`False`	Failed
A workflow starts without its required input fields	`False`	`False`	Passed
A child starts after its parent was cancelled	`False`	`False`	Passed
A deferred start begins beyond the workflow start deadline	`False`	`False`	Passed
unrelated tracing metadata	`True`	`True`	Passed
repeat validation is pure	`True`	`True`	Passed
two independent violations in variant	`False`	`False`	Passed

SHA-256 / 82657fcbb564c49ccd5bda736daf1826e489fb34619fbedcd3f497dde7168628

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 9 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:36:59.181459+00:00.

Case digest / 676053d7d67bfe6a262849b2ba605e6e57a1d74c1c06f2cc05bafd2e1ab39971