kezhenxu94 commented on a change in pull request #3170: Support upgrade backend w/o rebooting agents URL: https://github.com/apache/skywalking/pull/3170#discussion_r307961721
########## File path: apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/commands/CommandService.java ########## @@ -0,0 +1,117 @@ +/* + * 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.skywalking.apm.agent.core.commands; + +import org.apache.skywalking.apm.agent.core.boot.BootService; +import org.apache.skywalking.apm.agent.core.boot.DefaultImplementor; +import org.apache.skywalking.apm.agent.core.logging.api.ILog; +import org.apache.skywalking.apm.agent.core.logging.api.LogManager; +import org.apache.skywalking.apm.network.common.Command; +import org.apache.skywalking.apm.network.common.Commands; +import org.apache.skywalking.apm.network.trace.component.command.BaseCommand; +import org.apache.skywalking.apm.network.trace.component.command.CommandDeserializer; +import org.apache.skywalking.apm.network.trace.component.command.ServiceResetCommand; +import org.apache.skywalking.apm.network.trace.component.command.UnsupportedCommandException; + +import java.util.ArrayList; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.LinkedBlockingQueue; + +@DefaultImplementor +public class CommandService implements BootService { + + private static final ILog LOGGER = LogManager.getLogger(CommandService.class); + + private ExecutorService executorService = Executors.newSingleThreadExecutor(); + private LinkedBlockingQueue<BaseCommand> commands = new LinkedBlockingQueue<BaseCommand>(64); + private CommandSerialNumberCache serialNumberCache = new CommandSerialNumberCache(); + + @Override + public void prepare() throws Throwable { + } + + @Override + public void boot() throws Throwable { + executorService.submit(new Runnable() { + @Override + public void run() { + while (!Thread.currentThread().isInterrupted()) { + try { + BaseCommand command = commands.take(); + + if (isCommandExecuted(command)) { + continue; + } + + try { + CommandExecutors.newCommandExecutor(command).execute(); + serialNumberCache.add(command.getSerialNumber()); + } catch (ExecuteFailedException e) { + LOGGER.error(e, "Failed to execute command[{}].", command.getCommand()); + } + } catch (InterruptedException e) { + LOGGER.error(e, "Failed to take commands."); + } + } + } + + }); + } + + private boolean isCommandExecuted(BaseCommand command) { + return serialNumberCache.contain(command.getSerialNumber()); + } + + @Override + public void onComplete() throws Throwable { + + } + + @Override + public void shutdown() throws Throwable { + commands.drainTo(new ArrayList<BaseCommand>()); + executorService.shutdown(); + } + + public void receiveCommand(Commands commands) { + for (Command command : commands.getCommandsList()) { + try { + BaseCommand baseCommand = CommandDeserializer.deserialize(command); + + if (isCommandExecuted(baseCommand)) { + continue; + } + + if (ServiceResetCommand.NAME.equals(baseCommand.getCommand())) { Review comment: I'm thinking that whether we should put every command executor as a `BootService` or not, it's fine if we have just a few commands, but if we have many commands, the command executors would explode accordingly and I'm not sure whether it's a good idea to register so many `BootService` once ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
