Hadoop MapReduce计算框架命令行使用详情以及命令解析。具有三种文件类型：.sh文件、.cmd文件、.bash脚本文件，支持不同的操作系统。
bin模块具有以下文件：
所有的mapreduce命令都由bin/mapred脚本调用。
# 正在执行的脚本的名称
HADOOP_SHELL_EXECNAME="mapred"
# 获取当前执行的脚本文件的全路径，等价于与${BASH_SOURCE}
MYNAME="${BASH_SOURCE-$0}"
## @description build up the mapred command's usage text.
## @audience public
## @stability stable
## @replaceable no
## 建立mapred命令的用法文本
function hadoop_usage
{
hadoop_add_subcommand "classpath" client "prints the class path needed for running mapreduce subcommands"
hadoop_add_subcommand "envvars" client "display computed Hadoop environment variables"
hadoop_add_subcommand "historyserver" daemon "run job history servers as a standalone daemon"
hadoop_add_subcommand "hsadmin" admin "job history server admin interface"
hadoop_add_subcommand "job" client "manipulate MapReduce jobs"
hadoop_add_subcommand "pipes" client "run a Pipes job"
hadoop_add_subcommand "queue" client "get information regarding JobQueues"
hadoop_add_subcommand "sampler" client "sampler"
hadoop_add_subcommand "frameworkuploader" admin "mapreduce framework upload"
hadoop_add_subcommand "version" client "print the version"
hadoop_add_subcommand "minicluster" client "CLI MiniCluster"
hadoop_generate_usage "${HADOOP_SHELL_EXECNAME}" true
}
运行不带任何参数的mapred脚本将打印所有命令的描述，即hadoop_usage作用是输出mapred命令的描述。运行示例如下：
Usage: mapred [--config confdir] COMMAND
where COMMAND is one of:
pipes run a Pipes job
job manipulate MapReduce jobs
queue get information regarding JobQueues
classpath prints the class path needed for running
mapreduce subcommands
historyserver run job history servers as a standalone daemon
distcp <srcurl> <desturl> copy file or directories recursively
archive -archiveName NAME -p <parent path> <src>* <dest> create a hadoop archive
archive-logs combine aggregated logs into hadoop archives
hsadmin job history server admin interface
## @description Default command handler for hadoop command
## @audience public
## @stability stable
## @replaceable no
## @param CLI arguments
function mapredcmd_case
{
# 获取子命令
subcmd=$1
# shift命令用于对参数的移动(左移)，通常用于在不知道传入参数个数的情况下依次遍历每个参数然后进行相应处理
shift
# bash case循环命令语法
case ${subcmd} in
mradmin|jobtracker|tasktracker|groups)
hadoop_error "Sorry, the ${subcmd} command is no longer supported."
hadoop_error "You may find similar functionality with the \"yarn\" shell command."
hadoop_exit_with_usage 1
;;
classpath)
hadoop_do_classpath_subcommand HADOOP_CLASSNAME "$@"
;;
envvars)
echo "JAVA_HOME='${JAVA_HOME}'"
echo "HADOOP_MAPRED_HOME='${HADOOP_MAPRED_HOME}'"
echo "MAPRED_DIR='${MAPRED_DIR}'"
echo "MAPRED_LIB_JARS_DIR='${MAPRED_LIB_JARS_DIR}'"
echo "HADOOP_CONF_DIR='${HADOOP_CONF_DIR}'"
echo "HADOOP_TOOLS_HOME='${HADOOP_TOOLS_HOME}'"
echo "HADOOP_TOOLS_DIR='${HADOOP_TOOLS_DIR}'"
echo "HADOOP_TOOLS_LIB_JARS_DIR='${HADOOP_TOOLS_LIB_JARS_DIR}'"
exit 0
;;
historyserver)
HADOOP_SUBCMD_SUPPORTDAEMONIZATION="true"
HADOOP_CLASSNAME=org.apache.hadoop.mapreduce.v2.hs.JobHistoryServer
if [[ -n "${HADOOP_JOB_HISTORYSERVER_HEAPSIZE}" ]]; then
HADOOP_HEAPSIZE_MAX="${HADOOP_JOB_HISTORYSERVER_HEAPSIZE}"
fi
HADOOP_DAEMON_ROOT_LOGGER=${HADOOP_JHS_LOGGER:-$HADOOP_DAEMON_ROOT_LOGGER}
if [[ "${HADOOP_DAEMON_MODE}" != "default" ]]; then
hadoop_add_param HADOOP_OPTS mapred.jobsummary.logger "-Dmapred.jobsummary.logger=${HADOOP_DAEMON_ROOT_LOGGER}"
fi
;;
hsadmin)
HADOOP_CLASSNAME=org.apache.hadoop.mapreduce.v2.hs.client.HSAdmin
;;
job)
HADOOP_CLASSNAME=org.apache.hadoop.mapred.JobClient
;;
pipes)
HADOOP_CLASSNAME=org.apache.hadoop.mapred.pipes.Submitter
;;
queue)
HADOOP_CLASSNAME=org.apache.hadoop.mapred.JobQueueClient
;;
sampler)
HADOOP_CLASSNAME=org.apache.hadoop.mapred.lib.InputSampler
;;
frameworkuploader)
HADOOP_CLASSNAME=org.apache.hadoop.mapred.uploader.FrameworkUploader
;;
version)
HADOOP_CLASSNAME=org.apache.hadoop.util.VersionInfo
;;
minicluster)
hadoop_add_classpath "${HADOOP_YARN_HOME}/${YARN_DIR}/timelineservice"'/*'
hadoop_add_classpath "${HADOOP_YARN_HOME}/${YARN_DIR}/test"'/*'
HADOOP_CLASSNAME=org.apache.hadoop.mapreduce.MiniHadoopClusterManager
;;
*)
HADOOP_CLASSNAME="${subcmd}"
if ! hadoop_validate_classname "${HADOOP_CLASSNAME}"; then
hadoop_exit_with_usage 1
fi
;;
esac
}
hadoop命令的默认命令处理程序。
bin=$(cd -P -- "$(dirname -- "${MYNAME}")" >/dev/null && pwd -P)
# let's locate libexec...
if [[ -n "${HADOOP_HOME}" ]]; then
HADOOP_DEFAULT_LIBEXEC_DIR="${HADOOP_HOME}/libexec"
else
HADOOP_DEFAULT_LIBEXEC_DIR="${bin}/../libexec"
fi
HADOOP_LIBEXEC_DIR="${HADOOP_LIBEXEC_DIR:-$HADOOP_DEFAULT_LIBEXEC_DIR}"
HADOOP_NEW_CONFIG=true
if [[ -f "${HADOOP_LIBEXEC_DIR}/mapred-config.sh" ]]; then
# shellcheck source=./hadoop-mapreduce-project/bin/mapred-config.sh
. "${HADOOP_LIBEXEC_DIR}/mapred-config.sh"
else
echo "ERROR: Cannot execute ${HADOOP_LIBEXEC_DIR}/mapred-config.sh." 2>&1
exit 1
fi
# now that we have support code, let's abs MYNAME so we can use it later
MYNAME=$(hadoop_abs "${MYNAME}")
if [ $# = 0 ]; then
hadoop_exit_with_usage 1
fi
HADOOP_SUBCMD=$1
shift
if hadoop_need_reexec mapred "${HADOOP_SUBCMD}"; then
hadoop_uservar_su mapred "${HADOOP_SUBCMD}" \
"${MYNAME}" \
"--reexec" \
"${HADOOP_USER_PARAMS[@]}"
exit $?
fi
hadoop_verify_user_perm "${HADOOP_SHELL_EXECNAME}" "${HADOOP_SUBCMD}"
HADOOP_SUBCMD_ARGS=("$@")
if declare -f mapred_subcommand_"${HADOOP_SUBCMD}" >/dev/null 2>&1; then
hadoop_debug "Calling dynamically: mapred_subcommand_${HADOOP_SUBCMD} ${HADOOP_SUBCMD_ARGS[*]}"
"mapred_subcommand_${HADOOP_SUBCMD}" "${HADOOP_SUBCMD_ARGS[@]}"
else
mapredcmd_case "${HADOOP_SUBCMD}" "${HADOOP_SUBCMD_ARGS[@]}"
fi
hadoop_add_client_opts
if [[ ${HADOOP_WORKER_MODE} = true ]]; then
hadoop_common_worker_mode_execute "${HADOOP_MAPRED_HOME}/bin/mapred" "${HADOOP_USER_PARAMS[@]}"
exit $?
fi
hadoop_subcommand_opts "${HADOOP_SHELL_EXECNAME}" "${HADOOP_SUBCMD}"
# everything is in globals at this point, so call the generic handler
hadoop_generic_java_subcmd_handler
function hadoop_subproject_init
{
if [[ -z "${HADOOP_MAPRED_ENV_PROCESSED}" ]]; then
if [[ -e "${HADOOP_CONF_DIR}/mapred-env.sh" ]]; then
. "${HADOOP_CONF_DIR}/mapred-env.sh"
export HADOOP_MAPRED_ENV_PROCESSED=true
fi
fi
# at some point in time, someone thought it would be a good idea to
# create separate vars for every subproject. *sigh*
# let's perform some overrides and setup some defaults for bw compat
# this way the common hadoop var's == subproject vars and can be
# used interchangeable from here on out
# ...
# this should get deprecated at some point.
# hadoop_deprecate_envvar将旧的配置替换为新的配置，在旧配置存在的情况下
hadoop_deprecate_envvar HADOOP_MAPRED_LOG_DIR HADOOP_LOG_DIR
hadoop_deprecate_envvar HADOOP_MAPRED_LOGFILE HADOOP_LOGFILE
hadoop_deprecate_envvar HADOOP_MAPRED_NICENESS HADOOP_NICENESS
hadoop_deprecate_envvar HADOOP_MAPRED_STOP_TIMEOUT HADOOP_STOP_TIMEOUT
hadoop_deprecate_envvar HADOOP_MAPRED_PID_DIR HADOOP_PID_DIR
hadoop_deprecate_envvar HADOOP_MAPRED_ROOT_LOGGER HADOOP_ROOT_LOGGER
hadoop_deprecate_envvar HADOOP_JOB_HISTORYSERVER_OPTS MAPRED_HISTORYSERVER_OPTS
HADOOP_MAPRED_HOME="${HADOOP_MAPRED_HOME:-$HADOOP_HOME}"
hadoop_deprecate_envvar HADOOP_MAPRED_IDENT_STRING HADOOP_IDENT_STRING
}
初始化Hadoop mapReduce相关配置
if [[ -z "${HADOOP_LIBEXEC_DIR}" ]]; then
_mc_this="${BASH_SOURCE-$0}"
HADOOP_LIBEXEC_DIR=$(cd -P -- "$(dirname -- "${_mc_this}")" >/dev/null && pwd -P)
fi
# shellcheck source=./hadoop-common-project/hadoop-common/src/main/bin/hadoop-config.sh
if [[ -n "${HADOOP_COMMON_HOME}" ]] &&
[[ -e "${HADOOP_COMMON_HOME}/libexec/hadoop-config.sh" ]]; then
. "${HADOOP_COMMON_HOME}/libexec/hadoop-config.sh"
elif [[ -e "${HADOOP_LIBEXEC_DIR}/hadoop-config.sh" ]]; then
. "${HADOOP_LIBEXEC_DIR}/hadoop-config.sh"
elif [ -e "${HADOOP_HOME}/libexec/hadoop-config.sh" ]; then
. "${HADOOP_HOME}/libexec/hadoop-config.sh"
else
echo "ERROR: Hadoop common not found." 2>&1
exit 1
fi
mapReduce历史任务守护进程脚本。
function hadoop_usage
{
echo "Usage: mr-jobhistory-daemon.sh [--config confdir] (start|stop|status) <hadoop-command> <args...>"
}
调用mr-jobhistory-daemon.sh 脚本不带任何参数时，会执行hadoop_usage函数。
# let's locate libexec...
if [[ -n "${HADOOP_HOME}" ]]; then
HADOOP_DEFAULT_LIBEXEC_DIR="${HADOOP_HOME}/libexec"
else
this="${BASH_SOURCE-$0}"
bin=$(cd -P -- "$(dirname -- "${this}")" >/dev/null && pwd -P)
HADOOP_DEFAULT_LIBEXEC_DIR="${bin}/../libexec"
fi
HADOOP_LIBEXEC_DIR="${HADOOP_LIBEXEC_DIR:-$HADOOP_DEFAULT_LIBEXEC_DIR}"
# shellcheck disable=SC2034
HADOOP_NEW_CONFIG=true
if [[ -f "${HADOOP_LIBEXEC_DIR}/yarn-config.sh" ]]; then
. "${HADOOP_LIBEXEC_DIR}/yarn-config.sh"
else
echo "ERROR: Cannot execute ${HADOOP_LIBEXEC_DIR}/yarn-config.sh." 2>&1
exit 1
fi
daemonmode=$1
shift
hadoop_error "WARNING: Use of this script to ${daemonmode} the MR JobHistory daemon is deprecated."
hadoop_error "WARNING: Attempting to execute replacement \"mapred --daemon ${daemonmode}\" instead."
exec "${HADOOP_MAPRED_HOME}/bin/mapred" \
--config "${HADOOP_CONF_DIR}" --daemon "${daemonmode}" "$@"
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