def test_find_node_after_removal(self): nodes = ['0', '1', '2'] rendezvous = RendezvousHash(nodes=nodes) rendezvous.remove_node('1') self.assertEqual('0', rendezvous.find_node('ok')) self.assertEqual('0', rendezvous.find_node('mykey')) self.assertEqual('2', rendezvous.find_node('wat'))
def test_shrink(self): rendezvous = RendezvousHash() placements = {} for i in range(10): rendezvous.add_node(str(i)) placements[str(i)] = [] for i in range(1000): node = rendezvous.find_node(str(i)) placements[node].append(i) rendezvous.remove_node('9') new_placements = {} for i in range(9): new_placements[str(i)] = [] for i in range(1000): node = rendezvous.find_node(str(i)) new_placements[node].append(i) keys = [k for sublist in placements.values() for k in sublist] new_keys = [k for sublist in new_placements.values() for k in sublist] self.assertEqual(sorted(keys), sorted(new_keys)) added = 0 removed = 0 for node, assignments in placements.items(): after = set(assignments) before = set(new_placements.get(node, [])) removed += len(before.difference(after)) added += len(after.difference(before)) self.assertEqual(added, removed) self.assertEqual(202, (added + removed))
def test_find_node_after_removal(self): nodes = ['0', '1', '2'] rendezvous = RendezvousHash(nodes=nodes) rendezvous.remove_node('1') self.assertEqual('0', rendezvous.find_node('ok')) self.assertEqual('0', rendezvous.find_node('mykey')) self.assertEqual('2', rendezvous.find_node('wat'))
def test_shrink(self): rendezvous = RendezvousHash() placements = {} for i in range(10): rendezvous.add_node(str(i)) placements[str(i)] = [] for i in range(1000): node = rendezvous.find_node(str(i)) placements[node].append(i) rendezvous.remove_node('9') new_placements = {} for i in range(9): new_placements[str(i)] = [] for i in range(1000): node = rendezvous.find_node(str(i)) new_placements[node].append(i) keys = [k for sublist in placements.values() for k in sublist] new_keys = [k for sublist in new_placements.values() for k in sublist] self.assertEqual(sorted(keys), sorted(new_keys)) added = 0 removed = 0 for node, assignments in placements.items(): after = set(assignments) before = set(new_placements.get(node, [])) removed += len(before.difference(after)) added += len(after.difference(before)) self.assertEqual(added, removed) self.assertEqual(202, (added + removed))
def test_remove_node(self): nodes = ['0', '1', '2'] rendezvous = RendezvousHash(nodes=nodes) rendezvous.remove_node('2') self.assertEqual(2, len(rendezvous.nodes)) self.assertRaises(ValueError, rendezvous.remove_node, '2') self.assertEqual(2, len(rendezvous.nodes)) rendezvous.remove_node('1') self.assertEqual(1, len(rendezvous.nodes)) rendezvous.remove_node('0') self.assertEqual(0, len(rendezvous.nodes))
def test_remove_node(self): nodes = ['0', '1', '2'] rendezvous = RendezvousHash(nodes=nodes) rendezvous.remove_node('2') self.assertEqual(2, len(rendezvous.nodes)) self.assertRaises(ValueError, rendezvous.remove_node, '2') self.assertEqual(2, len(rendezvous.nodes)) rendezvous.remove_node('1') self.assertEqual(1, len(rendezvous.nodes)) rendezvous.remove_node('0') self.assertEqual(0, len(rendezvous.nodes))