File size: 9,354 Bytes
9368cc4 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 | #!/usr/bin/env python3
"""Third batch of `flow` tasks.
Instructions here report only what an operator could actually observe. No
diagnosis, no pointer at a module, no expected values -- the previous batch
scored too high partly because the instruction did the reasoning.
"""
import sys
from pathlib import Path
sys.path.insert(0, str(Path(__file__).parent))
from make_tasks import make, spec # noqa: E402
R = "python/scheduler"
# --------------------------------------------------- multi-file: retry transition
make(R, "retry-transition-illegal",
spec("python", "logic", 5, """
Any workflow that has to retry a task crashes the runner.
Steps: one task, RetryPolicy(max_attempts=3), start it, report it failed, wait
out the backoff, then start it again. The second start raises IllegalTransition.
This needs to work end to end without loosening what the state machine permits
in general -- finished work must still never be restartable.
"""),
[("flow/state.py",
""" RETRYING: {READY, FAILED},""",
""" RETRYING: {FAILED},"""),
("flow/scheduler.py",
""" if state.get(task_id) == st.PENDING:
state.set(task_id, st.READY)
elif state.get(task_id) == st.RETRYING:
state.set(task_id, st.READY)""",
""" if state.get(task_id) == st.PENDING:
state.set(task_id, st.READY)""")],
{"test_retry_transition.py": '''
import unittest
from flow import (IllegalTransition, ResourcePool, RetryPolicy, Scheduler,
Task, TaskGraph)
from flow import state as st
def one(**kw):
return Scheduler(TaskGraph([Task("job", **kw)]), ResourcePool({}))
class TestRetryCanRestart(unittest.TestCase):
def test_second_attempt_starts(self):
s = one(retry=RetryPolicy(max_attempts=3, base_delay=5.0))
state = s.new_state()
s.start("job", state)
s.fail("job", state)
s.clock.advance(5.0)
s.start("job", state)
self.assertEqual(state.get("job"), st.RUNNING)
def test_retry_then_succeed(self):
s = one(retry=RetryPolicy(max_attempts=3, base_delay=1.0))
state = s.new_state()
s.start("job", state)
s.fail("job", state)
s.clock.advance(1.0)
s.start("job", state)
s.finish("job", state, True)
self.assertEqual(state.get("job"), st.SUCCEEDED)
self.assertEqual(state.attempts["job"], 2)
def test_three_attempts(self):
s = one(retry=RetryPolicy(max_attempts=3, base_delay=1.0))
state = s.new_state()
for _ in range(3):
s.clock.advance(100.0)
s.start("job", state)
s.fail("job", state)
self.assertEqual(state.get("job"), st.FAILED)
self.assertEqual(state.attempts["job"], 3)
class TestStateMachineStillStrict(unittest.TestCase):
"""Loosening the table wholesale would let finished work restart."""
def test_succeeded_is_final(self):
s = one()
state = s.new_state()
s.start("job", state)
s.finish("job", state, True)
with self.assertRaises(IllegalTransition):
state.set("job", st.READY)
def test_failed_is_final(self):
s = one(retry=RetryPolicy(max_attempts=1))
state = s.new_state()
s.start("job", state)
s.fail("job", state)
with self.assertRaises(IllegalTransition):
state.set("job", st.READY)
def test_skipped_is_final(self):
s = one()
state = s.new_state()
state.set("job", st.SKIPPED)
with self.assertRaises(IllegalTransition):
state.set("job", st.READY)
def test_pending_cannot_jump_to_running(self):
s = one()
state = s.new_state()
with self.assertRaises(IllegalTransition):
state.set("job", st.RUNNING)
'''})
# --------------------------------------------------- graph aliasing
make(R, "dependents-aliasing",
spec("python", "logic", 4, """
Our graph inspector corrupts the graph it inspects.
The tool walks a workflow and, for reporting, collects the dependents of each
task into a set it then adds a marker into. After running it, scheduling
decisions for that graph come out wrong -- tasks are offered whose dependencies
have not run, and the topological order gains entries that were never tasks.
Reading the graph should not be able to change it. Please fix.
"""),
[("flow/graph.py",
""" if task_id not in self._tasks:
raise UnknownTask(task_id)
return set(self._dependents.get(task_id, ()))""",
""" if task_id not in self._tasks:
raise UnknownTask(task_id)
return self._dependents.setdefault(task_id, set())""")],
{"test_graph_isolation.py": '''
import unittest
from flow import Task, TaskGraph, UnknownTask
def diamond():
return TaskGraph([Task("root"),
Task("left", depends_on=frozenset({"root"})),
Task("right", depends_on=frozenset({"root"})),
Task("join", depends_on=frozenset({"left", "right"}))])
class TestReadsDoNotMutate(unittest.TestCase):
def test_mutating_the_result_does_not_touch_the_graph(self):
graph = diamond()
graph.dependents_of("root").add("intruder")
self.assertEqual(graph.dependents_of("root"), {"left", "right"})
def test_topological_order_is_unaffected(self):
graph = diamond()
before = graph.topological_order()
graph.dependents_of("root").add("intruder")
graph.dependents_of("left").add("another")
self.assertEqual(graph.topological_order(), before)
def test_upstream_result_is_also_a_copy(self):
graph = diamond()
graph.upstream_of("join").add("intruder")
self.assertEqual(graph.upstream_of("join"), {"left", "right"})
def test_descendants_unaffected_by_mutation(self):
graph = diamond()
graph.dependents_of("root").add("ghost")
self.assertEqual(graph.descendants_of("root"), {"left", "right", "join"})
class TestGraphStillReadsCorrectly(unittest.TestCase):
def test_dependents(self):
self.assertEqual(diamond().dependents_of("root"), {"left", "right"})
def test_leaf_has_no_dependents(self):
self.assertEqual(diamond().dependents_of("join"), set())
def test_unknown_task_raises(self):
with self.assertRaises(UnknownTask):
diamond().dependents_of("nope")
def test_topological_order_is_valid(self):
order = diamond().topological_order()
self.assertLess(order.index("root"), order.index("left"))
self.assertLess(order.index("left"), order.index("join"))
'''})
# --------------------------------------------------- condition scope check
make(R, "condition-scope-direct-only",
spec("python", "logic", 4, """
A graph we expected to be rejected ran anyway, and gated the wrong task.
We rely on the pre-run checks to catch conditions that reference something they
shouldn't. A task whose condition names a task two levels upstream of it passes
validation, then evaluates that name as false at run time because the result
isn't in scope, so the task is silently skipped on every run.
Either the check or the evaluation is wrong about which names are legitimate.
They should agree. Make validation accept exactly the names a condition can
actually read.
"""),
[("flow/validation.py",
""" upstream = graph.ancestors_of(task.task_id)""",
""" upstream = graph.upstream_of(task.task_id)""")],
{"test_condition_scope.py": '''
import unittest
from flow import Task, TaskGraph, validate_all
def chain_with_condition(condition):
return TaskGraph([
Task("a"),
Task("b", depends_on=frozenset({"a"})),
Task("c", depends_on=frozenset({"b"}), condition=condition),
])
class TestTransitiveNamesAreLegal(unittest.TestCase):
def test_grandparent_is_accepted(self):
self.assertEqual(validate_all(chain_with_condition("a"), {}), [])
def test_direct_parent_is_accepted(self):
self.assertEqual(validate_all(chain_with_condition("b"), {}), [])
def test_combination_of_both_is_accepted(self):
self.assertEqual(validate_all(chain_with_condition("a and b"), {}), [])
def test_deep_ancestor_is_accepted(self):
graph = TaskGraph([Task("a"),
Task("b", depends_on=frozenset({"a"})),
Task("c", depends_on=frozenset({"b"})),
Task("d", depends_on=frozenset({"c"}), condition="a")])
self.assertEqual(validate_all(graph, {}), [])
class TestOutOfScopeStillRejected(unittest.TestCase):
def test_unrelated_task_is_rejected(self):
graph = TaskGraph([Task("a"), Task("x"),
Task("b", depends_on=frozenset({"a"}), condition="x")])
problems = validate_all(graph, {})
self.assertTrue(any("x" in p for p in problems), problems)
def test_downstream_task_is_rejected(self):
graph = TaskGraph([Task("a", condition="b"),
Task("b", depends_on=frozenset({"a"}))])
self.assertTrue(validate_all(graph, {}))
def test_no_condition_is_fine(self):
self.assertEqual(validate_all(chain_with_condition(None), {}), [])
'''})
print("done")
|