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标题: 重磅！Flink源码解析环境准备及提交流程之环境准备 [打印本页]

作者: 尚硅谷教育 时间: 2021-9-28 10:00
标题: 重磅！Flink源码解析环境准备及提交流程之环境准备
Flink Yarn-per-job模式提交流程如图所示：

一、步伐起点

1. flink\bin\flink
=> exec $JAVA_RUN $JVM_ARGS "${log_setting[@]}"-classpath "`manglePathList"$CC_CLASSPATH:$INTERNAL_HADOOP_CLASSPATHS"`" org.apache.flink.client.cli.CliFrontend "$@"
2. flink/bin/config.sh(相关情况设置都在这里)
=> JAVA_RUN=java
=> JVM_ARGS="" => # Use conf/flink-conf.yaml
=>INTERNAL_HADOOP_CLASSPATHS="${HADOOP_CLASSPATH}:${HADOOP_CONF_DIR}:${YARN_CONF_DIR}"
3. 实行java -cp 就会开启JVM假造机，在假造机上开启CliFrontend进程，然后开始实行main方法
说明：java -cp和 -classpath一样，是指定类运行所依赖其他类的路径。
java -cp =》开启JVM假造机 =》开启Process（CliFrontend）=》步伐入口CliFrontend.main
4. Flink提交任务的入口类为CliFrontend。找到这个类的main方法：
在IDEA中全局查找（ctrl + n）：org.apache.flink.client.cli.CliFrontend，找到CliFrontend类，并找到main方法
/*** Submits the job based on the arguments.(根据参数提交作业)*/public static void main(final String[] args) { ... ... final CliFrontend cli = new CliFrontend( configuration, customCommandLines); ... ...}

二、步伐入口

CliFrontend.java

public static void main(final String[] args) { ... ... final CliFrontend cli = new CliFrontend( configuration, customCommandLines); ... ... int retCode =SecurityUtils.getInstalledContext() .runSecured(() -> cli.parseParameters(args)); ... ...}public int parseParameters(String[] args) { ... ... // get action String action = args[0]; // remove action from parameters final String[] params =Arrays.copyOfRange(args, 1, args.length); // do action switch (action) { case ACTION_RUN: run(params); return 0; case ACTION_LIST: list(params); return 0; case ACTION_INFO: info(params); return 0; case ACTION_CANCEL: cancel(params); return 0; case ACTION_STOP: stop(params); return 0; case ACTION_SAVEPOINT: savepoint(params); return 0; …… } ... ...}

三、解析输入参数

CliFrontend.java

protected void run(String[] args) throws Exception {    ... ...    //获取默认的运行参数    final Options commandOptions =CliFrontendParser.getRunCommandOptions();       // 解析参数，返回commandLine    final CommandLine commandLine = getCommandLine(commandOptions, args, true);    ... ...}public CommandLine getCommandLine(final OptionscommandOptions, final String[] args, final boolean stopAtNonOptions) throwsCliArgsException {       final Options commandLineOptions = CliFrontendParser.mergeOptions(commandOptions,customCommandLineOptions);       return CliFrontendParser.parse(commandLineOptions, args,stopAtNonOptions);}DefaultParser.javaDefaultParser.java
public class CliFrontendParser {       // 选项列表       static final Option HELP_OPTION = new Option("h", "help", false,                         "Show the helpmessage for the CLI Frontend or the action.");       static final Option JAR_OPTION = new Option("j", "jarfile", true, "Flink program JAR file.");       static final Option CLASS_OPTION = new Option("c", "class", true,                         "Class with theprogram entry point (\"main()\" method). Only needed if the " +                         "JAR file doesnot specify the class in its manifest.");... ...}DefaultParser.java
public CommandLine parse(Options options, String[] arguments,Properties properties, boolean stopAtNonOption)          throws ParseException{ ... ... if (arguments != null) {       for (String argument : arguments)       {          handleToken(argument);       } }... ...}private void handleToken(String token) throwsParseException{ currentToken = token;    if (skipParsing) {       cmd.addArg(token); } else if ("--".equals(token)) {       skipParsing = true; } else if (currentOption != null &¤tOption.acceptsArg() && isArgument(token)) {       currentOption.addValueForProcessing(Util.stripLeadingAndTrailingQuotes(token)); } else if (token.startsWith("--")){       // 解析--情势的参数       handleLongOption(token); } else if (token.startsWith("-") && !"-".equals(token)){       // 解析 -情势的参数       handleShortAndLongOption(token); } else {       handleUnknownToken(token); }    if (currentOption != null && !currentOption.acceptsArg()) {       currentOption = null; }}private void handleLongOption(String token) throwsParseException{ if (token.indexOf('=') == -1){       //解析–L、-L、--l、-l情势的参数（不包含=）       handleLongOptionWithoutEqual(token); } else{       // 解析--L=V、-L=V、--l=V、-l=V情势的参数（包含=）       handleLongOptionWithEqual(token); }}各种情况的解析，逻辑大要相同：去除-或--前缀，校验参数，以此中一个为例
private void handleLongOptionWithoutEqual(String token)throws ParseException{       // 校验参数是否合法 List matchingOpts = options.getMatchingOptions(token); if (matchingOpts.isEmpty()) {       handleUnknownToken(currentToken); } else if (matchingOpts.size() > 1) {       throw newAmbiguousOptionException(token, matchingOpts); } else{// 参数添加到实行命令       handleOption(options.getOption(matchingOpts.get(0))); }}Options.java：
public List getMatchingOptions(String opt){       // 去除 -或 -- 前缀 opt = Util.stripLeadingHyphens(opt);    List matchingOpts = newArrayList();    // for a perfect match return the singleoption only if (longOpts.keySet().contains(opt)) {       return Collections.singletonList(opt); }    for (String longOpt : longOpts.keySet()) {       if (longOpt.startsWith(opt))       {          matchingOpts.add(longOpt);       } }    return matchingOpts;}DefaultParser.java
private void handleOption(Option option) throwsParseException{ // check the previous option beforehandling the next one checkRequiredArgs();    option = (Option) option.clone();    updateRequiredOptions(option);    cmd.addOption(option);    if (option.hasArg()) {       currentOption = option; } else {       currentOption = null; }}

四、选择创建哪种类型的客户端

CliFrontend.java
public static void main(final String[] args) {       ... ...       final List customCommandLines = loadCustomCommandLines(                         configuration,                         configurationDirectory);       ... ...       final CliFrontend cli = new CliFrontend(                                  configuration,                                  customCommandLines);       ... ...}这里依次添加了 Yarn和Default（Standalone）两种客户端（后面根据isActive()选择）：
public static List loadCustomCommandLines(Configurationconfiguration, String configurationDirectory) {       ListcustomCommandLines = new ArrayList();       customCommandLines.add(newGenericCLI(configuration, configurationDirectory));       //    Commandline interface of the YARN session, with a special initialization here       //    toprefix all options with y/yarn.       final String flinkYarnSessionCLI ="org.apache.flink.yarn.cli.FlinkYarnSessionCli";       try {                customCommandLines.add(                         loadCustomCommandLine(flinkYarnSessionCLI,                                  configuration,                                  configurationDirectory,                                  "y",                                  "yarn"));       } catch (NoClassDefFoundError |Exception e) {                final StringerrorYarnSessionCLI ="org.apache.flink.yarn.cli.FallbackYarnSessionCli";                try {                         LOG.info("LoadingFallbackYarnSessionCli");                         customCommandLines.add(                                           loadCustomCommandLine(errorYarnSessionCLI,configuration));                } catch (Exception exception){                         LOG.warn("Couldnot load CLI class {}.", flinkYarnSessionCLI, e);                }       }       //    Tips:DefaultCLI must be added at last, because getActiveCustomCommandLine(..) willget the       //          active CustomCommandLine in order andDefaultCLI isActive always return true.       customCommandLines.add(new DefaultCLI(configuration));       return customCommandLines;}在run()内里，进行客户端的选择：
protected void run(String[] args) throws Exception {    ... ...    final CustomCommandLine activeCommandLine =                                  validateAndGetActiveCommandLine(checkNotNull(commandLine));... ...}public CustomCommandLine validateAndGetActiveCommandLine(CommandLinecommandLine) {... ...       for (CustomCommandLine cli :customCommandLines) {       ... ...       //在FlinkYarnSessionCli为active时优先返回FlinkYarnSessionCli。                //对于DefaultCli，它的isActive方法总是返回true。                if (cli.isActive(commandLine)) {                         return cli;                }       }... ...}FlinkYarnSessionCli.java => Yarn客户端isActive的判断逻辑：
public boolean isActive(CommandLine commandLine) {       final String jobManagerOption = commandLine.getOptionValue(addressOption.getOpt(),null);       //是否指定为per-job模式，即指定”-m yarn-cluster”; ID = "yarn-cluster"       final boolean yarnJobManager =ID.equals(jobManagerOption);       // 是否存在flink在yarn的appID，即yarn-session模式是否启动       final boolean hasYarnAppId =commandLine.hasOption(applicationId.getOpt())                         ||configuration.getOptional(YarnConfigOptions.APPLICATION_ID).isPresent();       // executor的名字为"yarn-session" 或 "yarn-per-job"       final boolean hasYarnExecutor = YarnSessionClusterExecutor.NAME.equals(configuration.get(DeploymentOptions.TARGET))                      ||YarnJobClusterExecutor.NAME.equals(configuration.get(DeploymentOptions.TARGET));       //       return hasYarnExecutor || yarnJobManager|| hasYarnAppId || (isYarnPropertiesFileMode(commandLine) &&yarnApplicationIdFromYarnProperties != null);}五、获取有效设置
CliFrontend.java
protected void run(String[] args) throws Exception {    ... ...    final Configuration effectiveConfiguration = getEffectiveConfiguration(                                  activeCommandLine,commandLine, programOptions, jobJars);... ...}private Configuration getEffectiveConfiguration(                final CommandLine commandLine,                final ProgramOptionsprogramOptions,                final List jobJars)throws FlinkException {... ...       final Configuration executorConfig =checkNotNull(activeCustomCommandLine)                                  .applyCommandLineOptionsToConfiguration(commandLine);... ...}FlinkYarnSessionCli.java
public Configuration applyCommandLineOptionsToConfiguration(CommandLinecommandLine) throws FlinkException {       // we ignore the addressOption becauseit can only contain "yarn-cluster"       final ConfigurationeffectiveConfiguration = new Configuration(configuration);       applyDescriptorOptionToConfig(commandLine,effectiveConfiguration);       final ApplicationId applicationId =getApplicationId(commandLine);       if (applicationId != null) {                final StringzooKeeperNamespace;                if (commandLine.hasOption(zookeeperNamespace.getOpt())){                         zooKeeperNamespace =commandLine.getOptionValue(zookeeperNamespace.getOpt());                } else {                         zooKeeperNamespace =effectiveConfiguration.getString(HA_CLUSTER_ID, applicationId.toString());                }                effectiveConfiguration.setString(HA_CLUSTER_ID, zooKeeperNamespace);                effectiveConfiguration.setString(YarnConfigOptions.APPLICATION_ID,ConverterUtils.toString(applicationId));                // TARGET 就是execution.target，目的实行器                //决定后面什么类型的实行器提交任务：yarn-session、yarn-per-job                effectiveConfiguration.setString(DeploymentOptions.TARGET, YarnSessionClusterExecutor.NAME);       } else {                effectiveConfiguration.setString(DeploymentOptions.TARGET, YarnJobClusterExecutor.NAME);       }       if (commandLine.hasOption(jmMemory.getOpt())) {                String jmMemoryVal =commandLine.getOptionValue(jmMemory.getOpt());                if(!MemorySize.MemoryUnit.hasUnit(jmMemoryVal)) {                         jmMemoryVal +="m";                }                effectiveConfiguration.setString(JobManagerOptions.JOB_MANAGER_HEAP_MEMORY,jmMemoryVal);       }       if (commandLine.hasOption(tmMemory.getOpt())) {                String tmMemoryVal =commandLine.getOptionValue(tmMemory.getOpt());                if(!MemorySize.MemoryUnit.hasUnit(tmMemoryVal)) {                         tmMemoryVal +="m";                }                effectiveConfiguration.set(TaskManagerOptions.TOTAL_PROCESS_MEMORY,MemorySize.parse(tmMemoryVal));       }       if (commandLine.hasOption(slots.getOpt())) {                effectiveConfiguration.setInteger(TaskManagerOptions.NUM_TASK_SLOTS,Integer.parseInt(commandLine.getOptionValue(slots.getOpt())));       }... ...}

六、调用用户代码的main方法

CliFrontend.java

protected void run(String[] args) throws Exception {    ... ...    executeProgram(effectiveConfiguration,program);... ...}protected void executeProgram(final Configurationconfiguration, final PackagedProgram program) throws ProgramInvocationException{       ClientUtils.executeProgram(newDefaultExecutorServiceLoader(), configuration, program, false, false);}ClientUtils.java
public static void executeProgram(                PipelineExecutorServiceLoader executorServiceLoader,                Configuration configuration,                PackagedProgram program,                boolean enforceSingleJobExecution,                boolean suppressSysout) throws ProgramInvocationException {       checkNotNull(executorServiceLoader);       final ClassLoader userCodeClassLoader =program.getUserCodeClassLoader();       final ClassLoader contextClassLoader =Thread.currentThread().getContextClassLoader();       try {                //设置当前的classloader为用户代码的classloader                Thread.currentThread().setContextClassLoader(userCodeClassLoader);                LOG.info("Startingprogram (detached: {})",!configuration.getBoolean(DeploymentOptions.ATTACHED));       //用户代码中的getExecutionEnvironment会返回该Environment                ContextEnvironment.setAsContext(                         executorServiceLoader,                         configuration,                         userCodeClassLoader,                         enforceSingleJobExecution,                         suppressSysout);                StreamContextEnvironment.setAsContext(                         executorServiceLoader,                         configuration,                         userCodeClassLoader,                         enforceSingleJobExecution,                         suppressSysout);                try {                         //调用用户代码的main方法                         program.invokeInteractiveModeForExecution();                } finally {                         ContextEnvironment.unsetAsContext();                         StreamContextEnvironment.unsetAsContext();                }       } finally {                Thread.currentThread().setContextClassLoader(contextClassLoader);       }}PackagedProgram.java
public void invokeInteractiveModeForExecution() throws ProgramInvocationException{
callMainMethod(mainClass, args);
}
private static void callMainMethod(Class entryClass,String[] args) throws ProgramInvocationException {       ... ...       mainMethod = entryClass.getMethod("main", String[].class);       ... ...    //反射调用main函数       mainMethod.invoke(null, (Object) args);       ... ...}

七、调用实行情况的execute方法

StreamExecutionEnvironment.java
public JobExecutionResult execute() throwsException { return execute(DEFAULT_JOB_NAME);}public JobExecutionResult execute(String jobName)throws Exception { ... ... return execute(getStreamGraph(jobName));}public JobExecutionResult execute(StreamGraphstreamGraph) throws Exception { final JobClient jobClient = executeAsync(streamGraph); ... ...}public JobClient executeAsync(StreamGraph streamGraph)throws Exception { ... ... //根据提交模式选择匹配的factory final PipelineExecutorFactoryexecutorFactory = executorServiceLoader.getExecutorFactory(configuration);... ... //选择合适的executor提交任务 CompletableFuturejobClientFuture = executorFactory .getExecutor(configuration) .execute(streamGraph, configuration);... ...}<hr>往期精彩内容：
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