Coverage for /pythoncovmergedfiles/medio/medio/src/airflow/build/lib/airflow/models/pool.py: 49%

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17# under the License. 

18from __future__ import annotations 

19 

20from typing import Iterable 

21 

22from sqlalchemy import Column, Integer, String, Text, func 

23from sqlalchemy.orm.session import Session 

24 

25from airflow.exceptions import AirflowException, PoolNotFound 

26from airflow.models.base import Base 

27from airflow.ti_deps.dependencies_states import EXECUTION_STATES 

28from airflow.typing_compat import TypedDict 

29from airflow.utils.session import NEW_SESSION, provide_session 

30from airflow.utils.sqlalchemy import nowait, with_row_locks 

31from airflow.utils.state import State 

32 

33 

34class PoolStats(TypedDict): 

35 """Dictionary containing Pool Stats""" 

36 

37 total: int 

38 running: int 

39 queued: int 

40 open: int 

41 

42 

43class Pool(Base): 

44 """the class to get Pool info.""" 

45 

46 __tablename__ = "slot_pool" 

47 

48 id = Column(Integer, primary_key=True) 

49 pool = Column(String(256), unique=True) 

50 # -1 for infinite 

51 slots = Column(Integer, default=0) 

52 description = Column(Text) 

53 

54 DEFAULT_POOL_NAME = "default_pool" 

55 

56 def __repr__(self): 

57 return str(self.pool) 

58 

59 @staticmethod 

60 @provide_session 

61 def get_pools(session: Session = NEW_SESSION): 

62 """Get all pools.""" 

63 return session.query(Pool).all() 

64 

65 @staticmethod 

66 @provide_session 

67 def get_pool(pool_name: str, session: Session = NEW_SESSION): 

68 """ 

69 Get the Pool with specific pool name from the Pools. 

70 

71 :param pool_name: The pool name of the Pool to get. 

72 :param session: SQLAlchemy ORM Session 

73 :return: the pool object 

74 """ 

75 return session.query(Pool).filter(Pool.pool == pool_name).first() 

76 

77 @staticmethod 

78 @provide_session 

79 def get_default_pool(session: Session = NEW_SESSION): 

80 """ 

81 Get the Pool of the default_pool from the Pools. 

82 

83 :param session: SQLAlchemy ORM Session 

84 :return: the pool object 

85 """ 

86 return Pool.get_pool(Pool.DEFAULT_POOL_NAME, session=session) 

87 

88 @staticmethod 

89 @provide_session 

90 def is_default_pool(id: int, session: Session = NEW_SESSION) -> bool: 

91 """ 

92 Check id if is the default_pool. 

93 

94 :param id: pool id 

95 :param session: SQLAlchemy ORM Session 

96 :return: True if id is default_pool, otherwise False 

97 """ 

98 return ( 

99 session.query(func.count(Pool.id)) 

100 .filter(Pool.id == id, Pool.pool == Pool.DEFAULT_POOL_NAME) 

101 .scalar() 

102 > 0 

103 ) 

104 

105 @staticmethod 

106 @provide_session 

107 def create_or_update_pool(name: str, slots: int, description: str, session: Session = NEW_SESSION): 

108 """Create a pool with given parameters or update it if it already exists.""" 

109 if not name: 

110 return 

111 pool = session.query(Pool).filter_by(pool=name).first() 

112 if pool is None: 

113 pool = Pool(pool=name, slots=slots, description=description) 

114 session.add(pool) 

115 else: 

116 pool.slots = slots 

117 pool.description = description 

118 

119 session.commit() 

120 

121 return pool 

122 

123 @staticmethod 

124 @provide_session 

125 def delete_pool(name: str, session: Session = NEW_SESSION): 

126 """Delete pool by a given name.""" 

127 if name == Pool.DEFAULT_POOL_NAME: 

128 raise AirflowException(f"{Pool.DEFAULT_POOL_NAME} cannot be deleted") 

129 

130 pool = session.query(Pool).filter_by(pool=name).first() 

131 if pool is None: 

132 raise PoolNotFound(f"Pool '{name}' doesn't exist") 

133 

134 session.delete(pool) 

135 session.commit() 

136 

137 return pool 

138 

139 @staticmethod 

140 @provide_session 

141 def slots_stats( 

142 *, 

143 lock_rows: bool = False, 

144 session: Session = NEW_SESSION, 

145 ) -> dict[str, PoolStats]: 

146 """ 

147 Get Pool stats (Number of Running, Queued, Open & Total tasks) 

148 

149 If ``lock_rows`` is True, and the database engine in use supports the ``NOWAIT`` syntax, then a 

150 non-blocking lock will be attempted -- if the lock is not available then SQLAlchemy will throw an 

151 OperationalError. 

152 

153 :param lock_rows: Should we attempt to obtain a row-level lock on all the Pool rows returns 

154 :param session: SQLAlchemy ORM Session 

155 """ 

156 from airflow.models.taskinstance import TaskInstance # Avoid circular import 

157 

158 pools: dict[str, PoolStats] = {} 

159 

160 query = session.query(Pool.pool, Pool.slots) 

161 

162 if lock_rows: 

163 query = with_row_locks(query, session=session, **nowait(session)) 

164 

165 pool_rows: Iterable[tuple[str, int]] = query.all() 

166 for (pool_name, total_slots) in pool_rows: 

167 if total_slots == -1: 

168 total_slots = float("inf") # type: ignore 

169 pools[pool_name] = PoolStats(total=total_slots, running=0, queued=0, open=0) 

170 

171 state_count_by_pool = ( 

172 session.query(TaskInstance.pool, TaskInstance.state, func.sum(TaskInstance.pool_slots)) 

173 .filter(TaskInstance.state.in_(list(EXECUTION_STATES))) 

174 .group_by(TaskInstance.pool, TaskInstance.state) 

175 ).all() 

176 

177 # calculate queued and running metrics 

178 for (pool_name, state, count) in state_count_by_pool: 

179 # Some databases return decimal.Decimal here. 

180 count = int(count) 

181 

182 stats_dict: PoolStats | None = pools.get(pool_name) 

183 if not stats_dict: 

184 continue 

185 # TypedDict key must be a string literal, so we use if-statements to set value 

186 if state == "running": 

187 stats_dict["running"] = count 

188 elif state == "queued": 

189 stats_dict["queued"] = count 

190 else: 

191 raise AirflowException(f"Unexpected state. Expected values: {EXECUTION_STATES}.") 

192 

193 # calculate open metric 

194 for pool_name, stats_dict in pools.items(): 

195 stats_dict["open"] = stats_dict["total"] - stats_dict["running"] - stats_dict["queued"] 

196 

197 return pools 

198 

199 def to_json(self): 

200 """ 

201 Get the Pool in a json structure 

202 

203 :return: the pool object in json format 

204 """ 

205 return { 

206 "id": self.id, 

207 "pool": self.pool, 

208 "slots": self.slots, 

209 "description": self.description, 

210 } 

211 

212 @provide_session 

213 def occupied_slots(self, session: Session = NEW_SESSION): 

214 """ 

215 Get the number of slots used by running/queued tasks at the moment. 

216 

217 :param session: SQLAlchemy ORM Session 

218 :return: the used number of slots 

219 """ 

220 from airflow.models.taskinstance import TaskInstance # Avoid circular import 

221 

222 return int( 

223 session.query(func.sum(TaskInstance.pool_slots)) 

224 .filter(TaskInstance.pool == self.pool) 

225 .filter(TaskInstance.state.in_(list(EXECUTION_STATES))) 

226 .scalar() 

227 or 0 

228 ) 

229 

230 @provide_session 

231 def running_slots(self, session: Session = NEW_SESSION): 

232 """ 

233 Get the number of slots used by running tasks at the moment. 

234 

235 :param session: SQLAlchemy ORM Session 

236 :return: the used number of slots 

237 """ 

238 from airflow.models.taskinstance import TaskInstance # Avoid circular import 

239 

240 return int( 

241 session.query(func.sum(TaskInstance.pool_slots)) 

242 .filter(TaskInstance.pool == self.pool) 

243 .filter(TaskInstance.state == State.RUNNING) 

244 .scalar() 

245 or 0 

246 ) 

247 

248 @provide_session 

249 def queued_slots(self, session: Session = NEW_SESSION): 

250 """ 

251 Get the number of slots used by queued tasks at the moment. 

252 

253 :param session: SQLAlchemy ORM Session 

254 :return: the used number of slots 

255 """ 

256 from airflow.models.taskinstance import TaskInstance # Avoid circular import 

257 

258 return int( 

259 session.query(func.sum(TaskInstance.pool_slots)) 

260 .filter(TaskInstance.pool == self.pool) 

261 .filter(TaskInstance.state == State.QUEUED) 

262 .scalar() 

263 or 0 

264 ) 

265 

266 @provide_session 

267 def scheduled_slots(self, session: Session = NEW_SESSION): 

268 """ 

269 Get the number of slots scheduled at the moment. 

270 

271 :param session: SQLAlchemy ORM Session 

272 :return: the number of scheduled slots 

273 """ 

274 from airflow.models.taskinstance import TaskInstance # Avoid circular import 

275 

276 return int( 

277 session.query(func.sum(TaskInstance.pool_slots)) 

278 .filter(TaskInstance.pool == self.pool) 

279 .filter(TaskInstance.state == State.SCHEDULED) 

280 .scalar() 

281 or 0 

282 ) 

283 

284 @provide_session 

285 def open_slots(self, session: Session = NEW_SESSION) -> float: 

286 """ 

287 Get the number of slots open at the moment. 

288 

289 :param session: SQLAlchemy ORM Session 

290 :return: the number of slots 

291 """ 

292 if self.slots == -1: 

293 return float("inf") 

294 else: 

295 return self.slots - self.occupied_slots(session)