spark-submit脚本分析

执行任务

./spark-submit \
--class cn.com.dtmobile.spark.DebugTest \
--master yarn \
--deploy-mode client \
--num-executors  \
--executor-cores  \
--executor-memory 1G \
/home/etluser/kong/debugTest/pucchSinr.jar

---

${SPARK_HOME}/bin/spark-submit脚本

if [ -z "${SPARK_HOME}" ]; then
  source "$(dirname "$")"/find-spark-home
fi

# disable randomized hash for string in Python 3.3+
export PYTHONHASHSEED=

exec "${SPARK_HOME}"/bin/spark-class org.apache.spark.deploy.SparkSubmit "$@"

$@表示所有接收的参数：

$@=

--class cn.com.dtmobile.spark.DebugTest --master yarn --deploy-mode client --num-executors  --executor-cores  --executor-memory 1G /home/etluser/kong/debugTest/pucchSinr.jar

最后exec执行的内容：
exec=

/home/etluser/kong/spark/spark-2.3.-bin/spark-2.3.-bin-hadoop2./bin/spark-class org.apache.spark.deploy.SparkSubmit --class cn.com.dtmobile.spark.DebugTest --master yarn --deploy-mode client --num-executors  --executor-cores  --executor-memory 1G /home/etluser/kong/debugTest/pucchSinr.jar

所以传给spark-class的参数为：

 org.apache.spark.deploy.SparkSubmit --class cn.com.dtmobile.spark.DebugTest --master yarn --deploy-mode client --num-executors  --executor-cores  --executor-memory 1G /home/etluser/kong/debugTest/pucchSinr.jar

${SPARK_HOME}/bin/spark-class脚本

if [ -z "${SPARK_HOME}" ]; then #如果${SPARK_HOME}长度为0
  source "$(dirname "$")"/find-spark-home
fi

. "${SPARK_HOME}"/bin/load-spark-env.sh

# Find the java binary
if [ -n "${JAVA_HOME}" ]; then  #如果${JAVA_HOME}长度不为0
  RUNNER="${JAVA_HOME}/bin/java"
else
  if [ "$(command -v java)" ]; then
    RUNNER="java"
  else
    echo "JAVA_HOME is not set" >&
    exit
  fi
fi

# Find Spark jars.
if [ -d "${SPARK_HOME}/jars" ]; then #如果${SPARK_HOME}/jars文件夹存在的话
  SPARK_JARS_DIR="${SPARK_HOME}/jars"
else
  SPARK_JARS_DIR="${SPARK_HOME}/assembly/target/scala-$SPARK_SCALA_VERSION/jars" #不存在的话就去assembly目录下找
fi

if [ ! -d "$SPARK_JARS_DIR" ] && [ -z "$SPARK_TESTING$SPARK_SQL_TESTING" ]; then #如果SPARK_JARS_DIR目录不存在，并且相关测试目录也为空
  echo "Failed to find Spark jars directory ($SPARK_JARS_DIR)." >&
  echo "You need to build Spark with the target \"package\" before running this program." >&
  exit
else
  LAUNCH_CLASSPATH="$SPARK_JARS_DIR/*" #指定加载时候的类路径为SPARK_JARS_DIR/所有jar包
fi

# Add the launcher build dir to the classpath if requested.
if [ -n "$SPARK_PREPEND_CLASSES" ]; then
  LAUNCH_CLASSPATH="${SPARK_HOME}/launcher/target/scala-$SPARK_SCALA_VERSION/classes:$LAUNCH_CLASSPATH"
fi

# For tests
if [[ -n "$SPARK_TESTING" ]]; then
  unset YARN_CONF_DIR
  unset HADOOP_CONF_DIR
fi

# The launcher library will print arguments separated by a NULL character, to allow arguments with
# characters that would be otherwise interpreted by the shell. Read that in a while loop, populating
# an array that will be used to exec the final command.
#
# The exit code of the launcher is appended to the output, so the parent shell removes it from the
# command array and checks the value to see if the launcher succeeded.
build_command() {
    #$RUNNER为java，调用类路径中的org.apache.spark.launcher.Main类 参数为spark-submit指定的所有参数，在这里调用launcher生成下面jvm command
  "$RUNNER" -Xmx128m -cp "$LAUNCH_CLASSPATH" org.apache.spark.launcher.Main "$@"
  printf "%d\0" $?
}

# Turn off posix mode since it does not allow process substitution
set +o posix
CMD=()
while IFS= read -d '' -r ARG; do
  CMD+=("$ARG")
done < <(build_command "$@")

COUNT=${#CMD[@]}
LAST=$((COUNT - ))
LAUNCHER_EXIT_CODE=${CMD[$LAST]}

# Certain JVM failures result in errors being printed to stdout (instead of stderr), which causes
# the code that parses the output of the launcher to get confused. In those cases, check if the
# exit code is an integer, and if it's not, handle it as a special error case.
if ! [[ $LAUNCHER_EXIT_CODE =~ ^[-]+$ ]]; then
  echo "${CMD[@]}" | head -n- >&
  exit
fi

if [ $LAUNCHER_EXIT_CODE !=  ]; then
  exit $LAUNCHER_EXIT_CODE
fi

CMD=("${CMD[@]:0:$LAST}")
exec "${CMD[@]}"

最后exec执行的CMD为：

${CMD[@]}=

/usr/lib/java/jdk1.8.0_144/bin/java -cp \
/home/etluser/kong/spark/spark-2.3.4-bin/spark-2.3.4-bin-hadoop2.6/conf/:/home/etluser/kong/spark/spark-2.3.4-bin/spark-2.3.4-bin-hadoop2.6/jars/* \
-Xmx1g \
org.apache.spark.deploy.SparkSubmit \
--master yarn \
--deploy-mode client \
--class cn.com.dtmobile.spark.DebugTest \
--num-executors 3 \
--executor-cores 2 \
--executor-memory 1G \
/home/etluser/kong/debugTest/pucchSinr.jar

也就是通过上面launcher生成的cmd

---

org.apache.spark.launcher.Main类

  public static void main(String[] argsArray) throws Exception {
    checkArgument(argsArray.length > 0, "Not enough arguments: missing class name.");
    //argsArray：spark-submit脚本传给spark-class的参数
    List<String> args = new ArrayList<>(Arrays.asList(argsArray));
    String className = args.remove(0); //这里className为org.apache.spark.deploy.SparkSubmit

    boolean printLaunchCommand = !isEmpty(System.getenv("SPARK_PRINT_LAUNCH_COMMAND"));
    AbstractCommandBuilder builder;
    if (className.equals("org.apache.spark.deploy.SparkSubmit")) {
      try {
        builder = new SparkSubmitCommandBuilder(args); //通过SparkSubmitCommandBuilder来生成cmd
      } catch (IllegalArgumentException e) {
        printLaunchCommand = false;
        System.err.println("Error: " + e.getMessage());
        System.err.println();

        MainClassOptionParser parser = new MainClassOptionParser();
        try {
          parser.parse(args);
        } catch (Exception ignored) {
          // Ignore parsing exceptions.
        }

        List<String> help = new ArrayList<>();
        if (parser.className != null) {
          help.add(parser.CLASS);
          help.add(parser.className);
        }
        help.add(parser.USAGE_ERROR);
        builder = new SparkSubmitCommandBuilder(help);
      }
    } else {
      builder = new SparkClassCommandBuilder(className, args);
    }

    Map<String, String> env = new HashMap<>();
    List<String> cmd = builder.buildCommand(env);//调用buildCommand生成cmd
    if (printLaunchCommand) {
      System.err.println("Spark Command: " + join(" ", cmd));
      System.err.println("========================================");
    }

    if (isWindows()) {
      System.out.println(prepareWindowsCommand(cmd, env));
    } else {
      // In bash, use NULL as the arg separator since it cannot be used in an argument.
      List<String> bashCmd = prepareBashCommand(cmd, env);
      for (String c : bashCmd) {
        System.out.print(c);
        System.out.print('\0');
      }
    }
  }

调用SparkSubmitCommandBuilder来生成Spark Submit命令，如下：

org.apache.spark.launcher.SparkSubmitCommandBuilder

//创建SparkSubmitCommandBuilder对象时候，对应的构造方法  
SparkSubmitCommandBuilder(List<String> args) {
    this.allowsMixedArguments = false;
    this.sparkArgs = new ArrayList<>();
    boolean isExample = false;
    List<String> submitArgs = args;

    if (args.size() > 0) {
      switch (args.get(0)) {
        case PYSPARK_SHELL://对应"pyspark-shell-main"
          this.allowsMixedArguments = true;
          appResource = PYSPARK_SHELL;
          submitArgs = args.subList(1, args.size());
          break;

        case SPARKR_SHELL://对应"sparkr-shell-main"
          this.allowsMixedArguments = true;
          appResource = SPARKR_SHELL;
          submitArgs = args.subList(1, args.size());
          break;

        case RUN_EXAMPLE:
          isExample = true;
          submitArgs = args.subList(1, args.size());
      }

      this.isExample = isExample;
      OptionParser parser = new OptionParser();//为SparkSubmitCommandBuilder的内部类，并且继承了SparkSubmitOptionParser类
      parser.parse(submitArgs);//parse方法为optionParser的父类方法，用于解析spark-submit的命令行参数
      this.isAppResourceReq = parser.isAppResourceReq;
    }  else {
      this.isExample = isExample;
      this.isAppResourceReq = false;
    }
  }

SparkSubmitOptionParser 类

org.apache.spark.launcher.SparkSubmitOptionParser

package org.apache.spark.launcher;

import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Parser for spark-submit command line options.
 * <p>
 * This class encapsulates the parsing code for spark-submit command line options, so that there
 * is a single list of options that needs to be maintained (well, sort of, but it makes it harder
 * to break things).
 */
class SparkSubmitOptionParser {

  // The following constants define the "main" name for the available options. They're defined
  // to avoid copy & paste of the raw strings where they're needed.
  //
  // The fields are not static so that they're exposed to Scala code that uses this class. See
  // SparkSubmitArguments.scala. That is also why this class is not abstract - to allow code to
  // easily use these constants without having to create dummy implementations of this class.
  protected final String CLASS = "--class";
  protected final String CONF = "--conf";
  protected final String DEPLOY_MODE = "--deploy-mode";
  protected final String DRIVER_CLASS_PATH = "--driver-class-path";
  protected final String DRIVER_CORES = "--driver-cores";
  protected final String DRIVER_JAVA_OPTIONS =  "--driver-java-options";
  protected final String DRIVER_LIBRARY_PATH = "--driver-library-path";
  protected final String DRIVER_MEMORY = "--driver-memory";
  protected final String EXECUTOR_MEMORY = "--executor-memory";
  protected final String FILES = "--files";
  protected final String JARS = "--jars";
  protected final String KILL_SUBMISSION = "--kill";
  protected final String MASTER = "--master";
  protected final String NAME = "--name";
  protected final String PACKAGES = "--packages";
  protected final String PACKAGES_EXCLUDE = "--exclude-packages";
  protected final String PROPERTIES_FILE = "--properties-file";
  protected final String PROXY_USER = "--proxy-user";
  protected final String PY_FILES = "--py-files";
  protected final String REPOSITORIES = "--repositories";
  protected final String STATUS = "--status";
  protected final String TOTAL_EXECUTOR_CORES = "--total-executor-cores";

  // Options that do not take arguments.
  protected final String HELP = "--help";
  protected final String SUPERVISE = "--supervise";
  protected final String USAGE_ERROR = "--usage-error";
  protected final String VERBOSE = "--verbose";
  protected final String VERSION = "--version";

  // Standalone-only options.

  // YARN-only options.
  protected final String ARCHIVES = "--archives";
  protected final String EXECUTOR_CORES = "--executor-cores";
  protected final String KEYTAB = "--keytab";
  protected final String NUM_EXECUTORS = "--num-executors";
  protected final String PRINCIPAL = "--principal";
  protected final String QUEUE = "--queue";

  /**
   * This is the canonical list of spark-submit options. Each entry in the array contains the
   * different aliases for the same option; the first element of each entry is the "official"
   * name of the option, passed to {@link #handle(String, String)}.
   * <p>
   * Options not listed here nor in the "switch" list below will result in a call to
   * {@link #handleUnknown(String)}.
   * <p>
   * These two arrays are visible for tests.
   */
  final String[][] opts = {
    { ARCHIVES },
    { CLASS },
    { CONF, "-c" },
    { DEPLOY_MODE },
    { DRIVER_CLASS_PATH },
    { DRIVER_CORES },
    { DRIVER_JAVA_OPTIONS },
    { DRIVER_LIBRARY_PATH },
    { DRIVER_MEMORY },
    { EXECUTOR_CORES },
    { EXECUTOR_MEMORY },
    { FILES },
    { JARS },
    { KEYTAB },
    { KILL_SUBMISSION },
    { MASTER },
    { NAME },
    { NUM_EXECUTORS },
    { PACKAGES },
    { PACKAGES_EXCLUDE },
    { PRINCIPAL },
    { PROPERTIES_FILE },
    { PROXY_USER },
    { PY_FILES },
    { QUEUE },
    { REPOSITORIES },
    { STATUS },
    { TOTAL_EXECUTOR_CORES },
  };

  /**
   * List of switches (command line options that do not take parameters) recognized by spark-submit.
   */
  final String[][] switches = {
    { HELP, "-h" },
    { SUPERVISE },
    { USAGE_ERROR },
    { VERBOSE, "-v" },
    { VERSION },
  };

  /**
   * Parse a list of spark-submit command line options.
   * <p>
   * See SparkSubmitArguments.scala for a more formal description of available options.
   *
   * @throws IllegalArgumentException If an error is found during parsing.
   */
  protected final void parse(List<String> args) {
    Pattern eqSeparatedOpt = Pattern.compile("(--[^=]+)=(.+)");

    int idx = 0;
    for (idx = 0; idx < args.size(); idx++) {
      String arg = args.get(idx);
      String value = null;

      Matcher m = eqSeparatedOpt.matcher(arg);
      if (m.matches()) {
        arg = m.group(1);
        value = m.group(2);
      }

      // Look for options with a value.主要用于解析opts里定义的参数，比如--class --deploy-mode --num-executors等等之类的参数
      String name = findCliOption(arg, opts);
      if (name != null) {
        if (value == null) {
          if (idx == args.size() - 1) {
            throw new IllegalArgumentException(
                String.format("Missing argument for option '%s'.", arg));
          }
          idx++;
          value = args.get(idx);
        }
        if (!handle(name, value)) { //handle方法调用的是OptionParser类重写之后的方法，将spark-submit放进来的参数对应值赋到spark对应的变量中
          break;
        }
        continue;
      }

      // Look for a switch.主要用于解析switches类的参数，比如--help --verbose等等这类的
      name = findCliOption(arg, switches);
      if (name != null) {
        if (!handle(name, null)) {
          break;
        }
        continue;
      }

      if (!handleUnknown(arg)) {
        break;
      }
    }

    if (idx < args.size()) {
      idx++;
    }
    handleExtraArgs(args.subList(idx, args.size()));
  }

  /**
   * Callback for when an option with an argument is parsed.
   *
   * @param opt The long name of the cli option (might differ from actual command line).
   * @param value The value. This will be <i>null</i> if the option does not take a value.
   * @return Whether to continue parsing the argument list.
   */
  protected boolean handle(String opt, String value) {
    throw new UnsupportedOperationException();
  }

  /**
   * Callback for when an unrecognized option is parsed.
   *
   * @param opt Unrecognized option from the command line.
   * @return Whether to continue parsing the argument list.
   */
  protected boolean handleUnknown(String opt) {
    throw new UnsupportedOperationException();
  }

  /**
   * Callback for remaining command line arguments after either {@link #handle(String, String)} or
   * {@link #handleUnknown(String)} return "false". This will be called at the end of parsing even
   * when there are no remaining arguments.
   *
   * @param extra List of remaining arguments.
   */
  protected void handleExtraArgs(List<String> extra) {
    throw new UnsupportedOperationException();
  }
　
  private String findCliOption(String name, String[][] available) {
    for (String[] candidates : available) {
      for (String candidate : candidates) {
        if (candidate.equals(name)) {
          return candidates[0];
        }
      }
    }
    return null;
  }

}

调用buildCommand方法：

org.apache.spark.launcher.SparkSubmitCommandBuilder#buildCommand

  public List<String> buildCommand(Map<String, String> env)
      throws IOException, IllegalArgumentException {
    if (PYSPARK_SHELL.equals(appResource) && isAppResourceReq) {
      return buildPySparkShellCommand(env);
    } else if (SPARKR_SHELL.equals(appResource) && isAppResourceReq) {
      return buildSparkRCommand(env);
    } else {
      return buildSparkSubmitCommand(env);//主要在这里
    }
  }

org.apache.spark.launcher.SparkSubmitCommandBuilder#buildSparkSubmitCommand

  private List<String> buildSparkSubmitCommand(Map<String, String> env)
      throws IOException, IllegalArgumentException {
    // Load the properties file and check whether spark-submit will be running the app's driver
    // or just launching a cluster app. When running the driver, the JVM's argument will be
    // modified to cover the driver's configuration.
    Map<String, String> config = getEffectiveConfig();
    boolean isClientMode = isClientMode(config);
    String extraClassPath = isClientMode ? config.get(SparkLauncher.DRIVER_EXTRA_CLASSPATH) : null;

    List<String> cmd = buildJavaCommand(extraClassPath);
    // Take Thrift Server as daemon
    if (isThriftServer(mainClass)) {
      addOptionString(cmd, System.getenv("SPARK_DAEMON_JAVA_OPTS"));
    }
    addOptionString(cmd, System.getenv("SPARK_SUBMIT_OPTS"));

    // We don't want the client to specify Xmx. These have to be set by their corresponding
    // memory flag --driver-memory or configuration entry spark.driver.memory
    String driverExtraJavaOptions = config.get(SparkLauncher.DRIVER_EXTRA_JAVA_OPTIONS);
    if (!isEmpty(driverExtraJavaOptions) && driverExtraJavaOptions.contains("Xmx")) {
      String msg = String.format("Not allowed to specify max heap(Xmx) memory settings through " +
                   "java options (was %s). Use the corresponding --driver-memory or " +
                   "spark.driver.memory configuration instead.", driverExtraJavaOptions);
      throw new IllegalArgumentException(msg);
    }

    if (isClientMode) {
      // Figuring out where the memory value come from is a little tricky due to precedence.
      // Precedence is observed in the following order:
      // - explicit configuration (setConf()), which also covers --driver-memory cli argument.
      // - properties file.
      // - SPARK_DRIVER_MEMORY env variable
      // - SPARK_MEM env variable
      // - default value (1g)
      // Take Thrift Server as daemon
      String tsMemory =
        isThriftServer(mainClass) ? System.getenv("SPARK_DAEMON_MEMORY") : null;
      String memory = firstNonEmpty(tsMemory, config.get(SparkLauncher.DRIVER_MEMORY),
        System.getenv("SPARK_DRIVER_MEMORY"), System.getenv("SPARK_MEM"), DEFAULT_MEM);
      cmd.add("-Xmx" + memory);
      addOptionString(cmd, driverExtraJavaOptions);
      mergeEnvPathList(env, getLibPathEnvName(),
        config.get(SparkLauncher.DRIVER_EXTRA_LIBRARY_PATH));
    }

    cmd.add("org.apache.spark.deploy.SparkSubmit");
    cmd.addAll(buildSparkSubmitArgs());
    return cmd;
  }

---

脚本中shell相关内容：

1.set -o posix

set命令是shell解释器的一个内置命令，用来设置shell解释器的属性，从而能够控制shell解释器的一些行为。

在set命令中，选项前面跟着 - 号表示开启这个选项， + 表示关闭这个选项。

POSIX，Portable Operating System Interface。
是UNIX系统的一个设计标准，很多类UNIX系统也在支持兼容这个标准，如Linux。
遵循这个标准的好处是软件可以跨平台。
所以windows也支持就很容易理解了，那么多优秀的开源软件，支持了这个这些软件就可能有windows版本，就可以完善丰富windows下的软件。
set -o posix：开启bash的posix模式。

2.command -v java

command [-pVv] command [arg ...]

用command指定可取消正常的shell function寻找。只有内建命令及在PATH中找得到的才会被执行。

"-p"选项，搜寻命令的方式是用PATH来找。"-V"或"-v"选项，会显示出该命令的一些简约描述。

4.read -d

-d ：表示delimiter，即定界符，一般情况下是以IFS为参数的间隔，但是通过-d，我们可以定义一直读到出现执行的字符位置。例如read –d madfds value，读到有m的字符的时候就不在继续向后读，例如输入为 hello m，有效值为“hello”，请注意m前面的空格等会被删除。这种方式可以输入多个字符串，例如定义“.”作为结符号等等

read命令 -n(不换行) -p(提示语句) -n(字符个数) -t(等待时间) -s(不回显)