fsk119 commented on code in PR #19823: URL: https://github.com/apache/flink/pull/19823#discussion_r896742925
########## flink-table/flink-sql-gateway/src/main/java/org/apache/flink/table/gateway/service/session/SessionManager.java: ########## @@ -0,0 +1,220 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.flink.table.gateway.service.session; + +import org.apache.flink.annotation.VisibleForTesting; +import org.apache.flink.configuration.Configuration; +import org.apache.flink.configuration.ReadableConfig; +import org.apache.flink.table.gateway.common.session.SessionEnvironment; +import org.apache.flink.table.gateway.common.session.SessionHandle; +import org.apache.flink.table.gateway.common.utils.SqlGatewayException; +import org.apache.flink.table.gateway.service.context.DefaultContext; +import org.apache.flink.table.gateway.service.context.SessionContext; +import org.apache.flink.table.gateway.service.utils.Constants; +import org.apache.flink.table.gateway.service.utils.ThreadUtils; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.Map; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.ScheduledFuture; +import java.util.concurrent.TimeUnit; + +import static org.apache.flink.table.gateway.common.config.SqlGatewayServiceConfigOptions.SQL_GATEWAY_SESSION_CHECK_INTERVAL; +import static org.apache.flink.table.gateway.common.config.SqlGatewayServiceConfigOptions.SQL_GATEWAY_SESSION_IDLE_TIMEOUT; +import static org.apache.flink.table.gateway.common.config.SqlGatewayServiceConfigOptions.SQL_GATEWAY_SESSION_MAX_NUM; +import static org.apache.flink.table.gateway.common.config.SqlGatewayServiceConfigOptions.SQL_GATEWAY_WORKER_KEEPALIVE_TIME; +import static org.apache.flink.table.gateway.common.config.SqlGatewayServiceConfigOptions.SQL_GATEWAY_WORKER_THREADS_MAX; +import static org.apache.flink.table.gateway.common.config.SqlGatewayServiceConfigOptions.SQL_GATEWAY_WORKER_THREADS_MIN; + +/** Manage the lifecycle of the {@code Session}. */ +public class SessionManager { + + private static final Logger LOG = LoggerFactory.getLogger(SessionManager.class); + + private final DefaultContext defaultContext; + + private final long idleTimeout; + private final long checkInterval; + private final int maxSessionCount; + + private final Map<SessionHandle, Session> sessions; + + private ExecutorService operationExecutorService; + private ScheduledExecutorService scheduledExecutorService; + private ScheduledFuture<?> timeoutCheckerFuture; + + public SessionManager(DefaultContext defaultContext) { + this.defaultContext = defaultContext; + ReadableConfig conf = defaultContext.getFlinkConfig(); + this.idleTimeout = conf.get(SQL_GATEWAY_SESSION_IDLE_TIMEOUT).toMillis(); + this.checkInterval = conf.get(SQL_GATEWAY_SESSION_CHECK_INTERVAL).toMillis(); + this.maxSessionCount = conf.get(SQL_GATEWAY_SESSION_MAX_NUM); + this.sessions = new ConcurrentHashMap<>(); + } + + public void start() { + if (checkInterval > 0 && idleTimeout > 0) { + scheduledExecutorService = Executors.newSingleThreadScheduledExecutor(); + timeoutCheckerFuture = + scheduledExecutorService.scheduleAtFixedRate( + () -> { + LOG.debug( + "Start to cleanup expired sessions, current session count: {}", + sessions.size()); + for (Map.Entry<SessionHandle, Session> entry : + sessions.entrySet()) { + SessionHandle sessionId = entry.getKey(); + Session session = entry.getValue(); + if (isSessionExpired(session)) { + LOG.info("Session {} is expired, close it...", sessionId); + closeSession(session); + } + } + LOG.debug( + "Removing expired session finished, current session count: {}", + sessions.size()); + }, + checkInterval, + checkInterval, + TimeUnit.MILLISECONDS); + } + + ReadableConfig conf = defaultContext.getFlinkConfig(); + operationExecutorService = + ThreadUtils.newDaemonQueuedThreadPool( + conf.get(SQL_GATEWAY_WORKER_THREADS_MIN), + conf.get(SQL_GATEWAY_WORKER_THREADS_MAX), + conf.get(SQL_GATEWAY_WORKER_KEEPALIVE_TIME).toMillis(), + Constants.OPERATION_POOL_NAME); + } + + public void stop() { + if (scheduledExecutorService != null) { + timeoutCheckerFuture.cancel(true); + scheduledExecutorService.shutdown(); + } + if (operationExecutorService != null) { + operationExecutorService.shutdown(); + } + LOG.info("SessionManager is stopped."); + } + + public Session getSession(SessionHandle sessionHandle) throws SqlGatewayException { + Session session = sessions.get(sessionHandle); + if (session == null) { + String msg = String.format("Session '%s' does not exist.", sessionHandle); + LOG.warn(msg); + throw new SqlGatewayException(msg); + } + session.touch(); + return session; + } + + /** + * Register the session into the {@link SessionManager}. + * + * <p>Use synchronized to keep the checkSessionCount and build the Session are atomic. + */ + public synchronized Session openSession(SessionEnvironment environment) + throws SqlGatewayException { + // check session limit + checkSessionCount(); + + Session session = null; + SessionHandle sessionId = null; + do { + sessionId = SessionHandle.create(); + } while (sessions.containsKey(sessionId)); + + SessionContext sessionContext = + SessionContext.create( + defaultContext, + sessionId, + environment.getSessionEndpointVersion(), + Configuration.fromMap(environment.getSessionConfig()), + operationExecutorService); + session = new Session(sessionContext); + sessions.put(sessionId, session); + + LOG.info( + "Session {} is opened, current sessions: {}.", + session.getSessionHandle(), + sessions.size()); + + return session; + } + + public void closeSession(SessionHandle sessionId) throws SqlGatewayException { + Session session = getSession(sessionId); + closeSession(session); + } + + // ------------------------------------------------------------------------------------------ + // Utilities + // ------------------------------------------------------------------------------------------ + + private void checkSessionCount() throws SqlGatewayException { + if (maxSessionCount <= 0) { + return; + } + if (sessions.size() >= maxSessionCount) { + String msg = + String.format( + "Failed to create session, the count of active sessions exceeds the max count: %s", + maxSessionCount); + LOG.warn(msg); + throw new SqlGatewayException(msg); + } + } + + private boolean isSessionExpired(Session session) { + if (idleTimeout > 0) { + return (System.currentTimeMillis() - session.getLastAccessTime()) > idleTimeout; + } else { + return false; + } + } + + private void closeSession(Session session) { + SessionHandle sessionId = session.getSessionHandle(); + sessions.remove(sessionId); + session.close(); + LOG.info("Session: {} is closed.", sessionId); Review Comment: SessionHandle#toString only contains the SessionHandler. -- This is an automated message from the Apache Git Service. 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