|
| 1 | +import unittest |
| 2 | +import time |
| 3 | +import uuid |
| 4 | +import struct |
| 5 | +import os |
| 6 | +import statistics |
| 7 | +from unittest.mock import Mock |
| 8 | + |
| 9 | +from cassandra.policies import ( |
| 10 | + DCAwareRoundRobinPolicy, |
| 11 | + RackAwareRoundRobinPolicy, |
| 12 | + TokenAwarePolicy, |
| 13 | + DefaultLoadBalancingPolicy, |
| 14 | + HostFilterPolicy |
| 15 | +) |
| 16 | +from cassandra.pool import Host |
| 17 | +from cassandra.cluster import SimpleConvictionPolicy |
| 18 | + |
| 19 | +# Mock for Connection/EndPoint since Host expects it |
| 20 | +class MockEndPoint(object): |
| 21 | + __slots__ = ('address',) |
| 22 | + |
| 23 | + def __init__(self, address): |
| 24 | + self.address = address |
| 25 | + def __str__(self): |
| 26 | + return self.address |
| 27 | + |
| 28 | +class MockStatement(object): |
| 29 | + __slots__ = ('routing_key', 'keyspace', 'table') |
| 30 | + |
| 31 | + def __init__(self, routing_key, keyspace="ks", table="tbl"): |
| 32 | + self.routing_key = routing_key |
| 33 | + self.keyspace = keyspace |
| 34 | + self.table = table |
| 35 | + |
| 36 | + def is_lwt(self): |
| 37 | + return False |
| 38 | + |
| 39 | +class MockTokenMap(object): |
| 40 | + __slots__ = ('token_class', 'get_replicas_func') |
| 41 | + def __init__(self, get_replicas_func): |
| 42 | + self.token_class = Mock() |
| 43 | + self.token_class.from_key = lambda k: k |
| 44 | + self.get_replicas_func = get_replicas_func |
| 45 | + |
| 46 | + def get_replicas(self, keyspace, token): |
| 47 | + return self.get_replicas_func(keyspace, token) |
| 48 | + |
| 49 | +class MockTablets(object): |
| 50 | + __slots__ = () |
| 51 | + def get_tablet_for_key(self, keyspace, table, key): |
| 52 | + return None |
| 53 | + |
| 54 | +class MockMetadata(object): |
| 55 | + __slots__ = ('_tablets', 'token_map', 'get_replicas_func', 'hosts_by_address') |
| 56 | + def __init__(self, get_replicas_func, hosts_by_address): |
| 57 | + self._tablets = MockTablets() |
| 58 | + self.token_map = MockTokenMap(get_replicas_func) |
| 59 | + self.get_replicas_func = get_replicas_func |
| 60 | + self.hosts_by_address = hosts_by_address |
| 61 | + |
| 62 | + def can_support_partitioner(self): |
| 63 | + return True |
| 64 | + |
| 65 | + def get_replicas(self, keyspace, key): |
| 66 | + return self.get_replicas_func(keyspace, key) |
| 67 | + |
| 68 | + def get_host(self, addr): |
| 69 | + return self.hosts_by_address.get(addr) |
| 70 | + |
| 71 | +class MockCluster(object): |
| 72 | + __slots__ = ('metadata',) |
| 73 | + def __init__(self, metadata): |
| 74 | + self.metadata = metadata |
| 75 | + |
| 76 | +class TestPolicyPerformance(unittest.TestCase): |
| 77 | + @classmethod |
| 78 | + def setUpClass(cls): |
| 79 | + if hasattr(os, 'sched_setaffinity'): |
| 80 | + try: |
| 81 | + # Pin to the first available CPU |
| 82 | + cpu = list(os.sched_getaffinity(0))[0] |
| 83 | + os.sched_setaffinity(0, {cpu}) |
| 84 | + print(f"Pinned to CPU {cpu}") |
| 85 | + except Exception as e: |
| 86 | + print(f"Could not pin CPU: {e}") |
| 87 | + |
| 88 | + # 1. Topology: 5 DCs, 3 Racks/DC, 3 Nodes/Rack = 45 Nodes |
| 89 | + cls.hosts = [] |
| 90 | + cls.hosts_map = {} # host_id -> Host |
| 91 | + cls.replicas_map = {} # routing_key -> list of replica hosts |
| 92 | + |
| 93 | + # Deterministic generation |
| 94 | + dcs = ['dc{}'.format(i) for i in range(5)] |
| 95 | + racks = ['rack{}'.format(i) for i in range(3)] |
| 96 | + nodes_per_rack = 3 |
| 97 | + |
| 98 | + ip_counter = 0 |
| 99 | + subnet_counter = 0 |
| 100 | + for dc in dcs: |
| 101 | + for rack in racks: |
| 102 | + subnet_counter += 1 |
| 103 | + for node_idx in range(nodes_per_rack): |
| 104 | + ip_counter += 1 |
| 105 | + address = "127.0.{}.{}".format(subnet_counter, node_idx + 1) |
| 106 | + h_id = uuid.UUID(int=ip_counter) |
| 107 | + h = Host(MockEndPoint(address), SimpleConvictionPolicy, host_id=h_id) |
| 108 | + h.set_location_info(dc, rack) |
| 109 | + cls.hosts.append(h) |
| 110 | + cls.hosts_map[h_id] = h |
| 111 | + |
| 112 | + # 2. Queries: 100,000 deterministic queries |
| 113 | + cls.query_count = 100000 |
| 114 | + cls.queries = [] |
| 115 | + cls.results = [] |
| 116 | + # We'll use simple packed integers as routing keys |
| 117 | + for i in range(cls.query_count): |
| 118 | + key = struct.pack('>I', i) |
| 119 | + cls.queries.append(MockStatement(routing_key=key)) |
| 120 | + |
| 121 | + # Pre-calculate replicas for TokenAware: |
| 122 | + # Deterministically pick 3 replicas based on the key index |
| 123 | + # This simulates the metadata.get_replicas behavior |
| 124 | + # We pick index i, i+1, i+2 mod 45 |
| 125 | + replicas = [] |
| 126 | + for r in range(3): |
| 127 | + idx = (i + r) % len(cls.hosts) |
| 128 | + replicas.append(cls.hosts[idx]) |
| 129 | + cls.replicas_map[key] = replicas |
| 130 | + |
| 131 | + def _get_replicas_side_effect(self, keyspace, key): |
| 132 | + return self.replicas_map.get(key, []) |
| 133 | + |
| 134 | + def _setup_cluster_mock(self): |
| 135 | + hosts_by_address = {} |
| 136 | + for host in self.hosts: |
| 137 | + addr = getattr(host, 'address', None) |
| 138 | + if addr is None and getattr(host, 'endpoint', None) is not None: |
| 139 | + addr = getattr(host.endpoint, 'address', None) |
| 140 | + if addr is not None: |
| 141 | + hosts_by_address[addr] = host |
| 142 | + metadata = MockMetadata(self._get_replicas_side_effect, hosts_by_address) |
| 143 | + return MockCluster(metadata) |
| 144 | + |
| 145 | + def _run_benchmark(self, name, policy): |
| 146 | + # Setup |
| 147 | + cluster = self._setup_cluster_mock() |
| 148 | + policy.populate(cluster, self.hosts) |
| 149 | + |
| 150 | + # Warmup |
| 151 | + for _ in range(100): |
| 152 | + list(policy.make_query_plan(working_keyspace="ks", query=self.queries[0])) |
| 153 | + |
| 154 | + # Run multiple iterations to reduce noise |
| 155 | + iterations = 5 |
| 156 | + timings = [] |
| 157 | + |
| 158 | + for _ in range(iterations): |
| 159 | + start_time = time.perf_counter() |
| 160 | + for q in self.queries: |
| 161 | + # We consume the iterator to ensure full plan generation cost is paid |
| 162 | + for _ in policy.make_query_plan(working_keyspace="ks", query=q): |
| 163 | + pass |
| 164 | + end_time = time.perf_counter() |
| 165 | + timings.append(end_time - start_time) |
| 166 | + |
| 167 | + # Use median to filter outliers |
| 168 | + duration = statistics.median(timings) |
| 169 | + |
| 170 | + count = len(self.queries) |
| 171 | + ops_per_sec = count / duration |
| 172 | + kops = int(ops_per_sec / 1000) |
| 173 | + |
| 174 | + self.results.append((name, count, duration, kops)) |
| 175 | + return ops_per_sec |
| 176 | + |
| 177 | + @classmethod |
| 178 | + def tearDownClass(cls): |
| 179 | + print("\n\n=== Performance Benchmarks ===") |
| 180 | + print(f"{'Policy':<30} | {'Ops':<10} | {'Time (s)':<10} | {'Kops/s':<10}") |
| 181 | + print("-" * 70) |
| 182 | + for name, count, duration, kops in cls.results: |
| 183 | + print(f"{name:<30} | {count:<10} | {duration:<10.4f} | {kops:<10}") |
| 184 | + print("-" * 70) |
| 185 | + |
| 186 | + def test_dc_aware(self): |
| 187 | + # Local DC = dc0, 1 remote host per DC |
| 188 | + policy = DCAwareRoundRobinPolicy(local_dc='dc0', used_hosts_per_remote_dc=1) |
| 189 | + self._run_benchmark("DCAware", policy) |
| 190 | + |
| 191 | + def test_rack_aware(self): |
| 192 | + # Local DC = dc0, Local Rack = rack0, 1 remote host per DC |
| 193 | + policy = RackAwareRoundRobinPolicy(local_dc='dc0', local_rack='rack0', used_hosts_per_remote_dc=1) |
| 194 | + self._run_benchmark("RackAware", policy) |
| 195 | + |
| 196 | + def test_token_aware_wrapping_dc_aware(self): |
| 197 | + child = DCAwareRoundRobinPolicy(local_dc='dc0', used_hosts_per_remote_dc=1) |
| 198 | + policy = TokenAwarePolicy(child, shuffle_replicas=False) # False for strict determinism in test if needed |
| 199 | + self._run_benchmark("TokenAware(DCAware)", policy) |
| 200 | + |
| 201 | + def test_token_aware_wrapping_rack_aware(self): |
| 202 | + child = RackAwareRoundRobinPolicy(local_dc='dc0', local_rack='rack0', used_hosts_per_remote_dc=1) |
| 203 | + policy = TokenAwarePolicy(child, shuffle_replicas=False) |
| 204 | + self._run_benchmark("TokenAware(RackAware)", policy) |
| 205 | + |
| 206 | + def test_default_wrapping_dc_aware(self): |
| 207 | + child = DCAwareRoundRobinPolicy(local_dc='dc0', used_hosts_per_remote_dc=1) |
| 208 | + policy = DefaultLoadBalancingPolicy(child) |
| 209 | + self._run_benchmark("Default(DCAware)", policy) |
| 210 | + |
| 211 | + def test_host_filter_wrapping_dc_aware(self): |
| 212 | + child = DCAwareRoundRobinPolicy(local_dc='dc0', used_hosts_per_remote_dc=1) |
| 213 | + policy = HostFilterPolicy(child_policy=child, predicate=lambda host: host.rack != 'rack2') |
| 214 | + self._run_benchmark("HostFilter(DCAware)", policy) |
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