Hadoop服务开启与关闭及其源码介绍

news/2024/5/20 2:31:54 标签: hadoop, hdfs, big data

文章目录

  • Hadoop的服务开启与关闭
    • 1、开启关闭所有服务（不推荐）
      • 1.命令使用
      • 2.start-all.sh脚本
      • 3.stop-all.sh
    • 2、开启Hadoop所有服务★★★
      • 1.命令使用
      • 2.start-dfs.sh
      • 3.start-yarn.sh
    • 3、关闭Hadoop所有服务★★★
      • 1. 命令使用
      • 2.stop-dfs.sh
      • 3.stop-yarn.sh
    • 4、利用浏览器查看hadoop状态
      • 1.访问HDFS控制页面
      • 2.访问历史服务（historyserver）
      • 3.进程监控（application monitoring）

Hadoop的服务开启与关闭

1、开启关闭所有服务（不推荐）

1.命令使用

#开启所有服务
start-all.sh
#关闭所有服务
stop-all.sh

2.start-all.sh脚本

#定义异常退出的方法
function hadoop_abort_startall()
{
  exit 1
}

# 定位执行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}"
#检查是否可以执行
HADOOP_NEW_CONFIG=true
if [[ -f "${HADOOP_LIBEXEC_DIR}/hadoop-config.sh" ]]; then
  . "${HADOOP_LIBEXEC_DIR}/hadoop-config.sh"
else
  echo "ERROR: Cannot execute ${HADOOP_LIBEXEC_DIR}/hadoop-config.sh." 2>&1
  exit 1
fi

if ! hadoop_privilege_check; then
  trap hadoop_abort_startall INT
  hadoop_error "WARNING: Attempting to start all Apache Hadoop daemons as ${USER} in 10 seconds."
  hadoop_error "WARNING: This is not a recommended production deployment configuration."
  hadoop_error "WARNING: Use CTRL-C to abort."
  sleep 10
  trap - INT
fi

# 调用start-dfs.sh开启hdfs服务
if [[ -f "${HADOOP_HDFS_HOME}/sbin/start-dfs.sh" ]]; then
  "${HADOOP_HDFS_HOME}/sbin/start-dfs.sh" --config "${HADOOP_CONF_DIR}"
fi

# 调用start-yarn.sh开启yarn服务
if [[ -f "${HADOOP_YARN_HOME}/sbin/start-yarn.sh" ]]; then
  "${HADOOP_YARN_HOME}/sbin/start-yarn.sh" --config "${HADOOP_CONF_DIR}"
fi

3.stop-all.sh

#定义异常退出
function hadoop_abort_stopall()
{
  exit 1
}

# 定位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 "${HADOOP_LIBEXEC_DIR}/hadoop-config.sh" ]]; then
  . "${HADOOP_LIBEXEC_DIR}/hadoop-config.sh"
else
  echo "ERROR: Cannot execute ${HADOOP_LIBEXEC_DIR}/hadoop-config.sh." 2>&1
  exit 1
fi

if ! hadoop_privilege_check; then
  trap hadoop_abort_stopall INT
  hadoop_error "WARNING: Stopping all Apache Hadoop daemons as ${USER} in 10 seconds."
  hadoop_error "WARNING: Use CTRL-C to abort."
  sleep 10
  trap - INT
fi

# 执行stop-dfs.sh关闭hdfs
if [[ -f "${HADOOP_HDFS_HOME}/sbin/stop-dfs.sh" ]]; then
  "${HADOOP_HDFS_HOME}/sbin/stop-dfs.sh" --config "${HADOOP_CONF_DIR}"
fi

# 指定stop-yarn.sh关闭yarn
if [[ -f "${HADOOP_HDFS_HOME}/sbin/stop-yarn.sh" ]]; then
  "${HADOOP_HDFS_HOME}/sbin/stop-yarn.sh" --config "${HADOOP_CONF_DIR}"
fi

2、开启Hadoop所有服务★★★

1.命令使用

#开启HDFS服务
start-dfs.sh
#------------------------------------------------------------------
Starting namenodes on [single01]
Last login: Wed Dec 29 17:17:39 CST 2021 from 192.168.50.1 on pts/0
Starting datanodes
Last login: Wed Dec 29 17:17:54 CST 2021 on pts/0
Starting secondary namenodes [single01]
Last login: Wed Dec 29 17:17:56 CST 2021 on pts/0
#------------------------------------------------------------------
#开启yarn服务
start-yarn.sh
#-------------------------------------------------
Starting resourcemanager
Last login: Wed Dec 29 17:17:59 CST 2021 on pts/0
Starting nodemanagers
Last login: Wed Dec 29 17:18:49 CST 2021 on pts/0
#------------------------------------------------
#开启历史记录服务
mapred --daemon start historyserver
#查看是否全部开启
jps
#--------------------
1936 NameNode
2770 NodeManager
3202 JobHistoryServer
3251 Jps
2618 ResourceManager
2110 DataNode
2334 SecondaryNameNod
#--------------------

2.start-dfs.sh

#!/usr/bin/env bash
function hadoop_usage
{
  echo "Usage: start-dfs.sh [-upgrade|-rollback] [-clusterId]"
}

this="${BASH_SOURCE-$0}"
bin=$(cd -P -- "$(dirname -- "${this}")" >/dev/null && pwd -P)

# 定位本地的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}"
# 检查配置信息
HADOOP_NEW_CONFIG=true
if [[ -f "${HADOOP_LIBEXEC_DIR}/hdfs-config.sh" ]]; then
  . "${HADOOP_LIBEXEC_DIR}/hdfs-config.sh"
else
  echo "ERROR: Cannot execute ${HADOOP_LIBEXEC_DIR}/hdfs-config.sh." 2>&1
  exit 1
fi

# 获取执行参数
if [[ $# -ge 1 ]]; then
  startOpt="$1"
  shift
  case "$startOpt" in
    -upgrade)
      nameStartOpt="$startOpt"
    ;;
    -rollback)
      dataStartOpt="$startOpt"
    ;;
    *)
      hadoop_exit_with_usage 1
    ;;
  esac
fi


#其他的情况
nameStartOpt="$nameStartOpt $*"

#---------------------------------------------------------
# 定义namenodes

NAMENODES=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -namenodes 2>/dev/null)

# 获取hostname
if [[ -z "${NAMENODES}" ]]; then
  NAMENODES=$(hostname)
fi

#提示信息输出
echo "Starting namenodes on [${NAMENODES}]"

#启动hadoop的NameNode服务
hadoop_uservar_su hdfs namenode "${HADOOP_HDFS_HOME}/bin/hdfs" \
    --workers \
    --config "${HADOOP_CONF_DIR}" \
    --hostnames "${NAMENODES}" \
    --daemon start \
    namenode ${nameStartOpt}

HADOOP_JUMBO_RETCOUNTER=$?

#---------------------------------------------------------
# 提示信息输出
echo "Starting datanodes"
#启动DataNode服务
hadoop_uservar_su hdfs datanode "${HADOOP_HDFS_HOME}/bin/hdfs" \
    --workers \
    --config "${HADOOP_CONF_DIR}" \
    --daemon start \
    datanode ${dataStartOpt}
(( HADOOP_JUMBO_RETCOUNTER=HADOOP_JUMBO_RETCOUNTER + $? ))

#---------------------------------------------------------
 (if any)

SECONDARY_NAMENODES=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -secondarynamenodes 2>/dev/null)
#
if [[ -n "${SECONDARY_NAMENODES}" ]]; then

  if [[ "${NAMENODES}" =~ , ]]; then

    hadoop_error "WARNING: Highly available NameNode is configured."
    hadoop_error "WARNING: Skipping SecondaryNameNode."

  else

    if [[ "${SECONDARY_NAMENODES}" == "0.0.0.0" ]]; then
      SECONDARY_NAMENODES=$(hostname)
    fi
	#提示信息输出
    echo "Starting secondary namenodes [${SECONDARY_NAMENODES}]"
	# 启动secondary namenodes
    hadoop_uservar_su hdfs secondarynamenode "${HADOOP_HDFS_HOME}/bin/hdfs" \
      --workers \
      --config "${HADOOP_CONF_DIR}" \
      --hostnames "${SECONDARY_NAMENODES}" \
      --daemon start \
      secondarynamenode
    (( HADOOP_JUMBO_RETCOUNTER=HADOOP_JUMBO_RETCOUNTER + $? ))
  fi
fi

#---------------------------------------------------------
# 对节点进行集群管理journalnode

JOURNAL_NODES=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -journalNodes 2>&-)

if [[ "${#JOURNAL_NODES}" != 0 ]]; then
  echo "Starting journal nodes [${JOURNAL_NODES}]"
  #开其集群管理的journalnode
  hadoop_uservar_su hdfs journalnode "${HADOOP_HDFS_HOME}/bin/hdfs" \
    --workers \
    --config "${HADOOP_CONF_DIR}" \
    --hostnames "${JOURNAL_NODES}" \
    --daemon start \
    journalnode
   (( HADOOP_JUMBO_RETCOUNTER=HADOOP_JUMBO_RETCOUNTER + $? ))
fi

#---------------------------------------------------------
# 如果在高可用状态启动失败进行Zookeeper失败重启
AUTOHA_ENABLED=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey dfs.ha.automatic-failover.enabled | tr '[:upper:]' '[:lower:]')
if [[ "${AUTOHA_ENABLED}" = "true" ]]; then
  echo "Starting ZK Failover Controllers on NN hosts [${NAMENODES}]"
  # 启动Zookeeper服务
  hadoop_uservar_su hdfs zkfc "${HADOOP_HDFS_HOME}/bin/hdfs" \
    --workers \
    --config "${HADOOP_CONF_DIR}" \
    --hostnames "${NAMENODES}" \
    --daemon start \
    zkfc
  (( HADOOP_JUMBO_RETCOUNTER=HADOOP_JUMBO_RETCOUNTER + $? ))
fi

exit ${HADOOP_JUMBO_RETCOUNTER}

3.start-yarn.sh

function hadoop_usage
{
  hadoop_generate_usage "${MYNAME}" false
}
#获取资源参数
MYNAME="${BASH_SOURCE-$0}"
# 获取文件路径
bin=$(cd -P -- "$(dirname -- "${MYNAME}")" >/dev/null && pwd -P)

# 定位执行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}"
# 定义失败信息输出
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

HADOOP_JUMBO_RETCOUNTER=0

# 开启resourceManager
HARM=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey yarn.resourcemanager.ha.enabled 2>&-)
if [[ ${HARM} = "false" ]]; then
  #提示信息输出
  echo "Starting resourcemanager"
  #执行resourceManager执行指令
  hadoop_uservar_su yarn resourcemanager "${HADOOP_YARN_HOME}/bin/yarn" \
      --config "${HADOOP_CONF_DIR}" \
      --daemon start \
      resourcemanager
  (( HADOOP_JUMBO_RETCOUNTER=HADOOP_JUMBO_RETCOUNTER + $? ))
else
  logicals=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey yarn.resourcemanager.ha.rm-ids 2>&-)
  logicals=${logicals//,/ }
  for id in ${logicals}
  do
      rmhost=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey "yarn.resourcemanager.hostname.${id}" 2>&-)
      RMHOSTS="${RMHOSTS} ${rmhost}"
  done
  echo "Starting resourcemanagers on [${RMHOSTS}]"
  hadoop_uservar_su yarn resourcemanager "${HADOOP_YARN_HOME}/bin/yarn" \
      --config "${HADOOP_CONF_DIR}" \
      --daemon start \
      --workers \
      --hostnames "${RMHOSTS}" \
      resourcemanager
  (( HADOOP_JUMBO_RETCOUNTER=HADOOP_JUMBO_RETCOUNTER + $? ))
fi

# 开启nodemanager
echo "Starting nodemanagers"
# 开启nodemanager
hadoop_uservar_su yarn nodemanager "${HADOOP_YARN_HOME}/bin/yarn" \
    --config "${HADOOP_CONF_DIR}" \
    --workers \
    --daemon start \
    nodemanager
(( HADOOP_JUMBO_RETCOUNTER=HADOOP_JUMBO_RETCOUNTER + $? ))


# 开启proxyserver
PROXYSERVER=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey  yarn.web-proxy.address 2>&- | cut -f1 -d:)
if [[ -n ${PROXYSERVER} ]]; then
 hadoop_uservar_su yarn proxyserver "${HADOOP_YARN_HOME}/bin/yarn" \
      --config "${HADOOP_CONF_DIR}" \
      --workers \
      --hostnames "${PROXYSERVER}" \
      --daemon start \
      proxyserver
 (( HADOOP_JUMBO_RETCOUNTER=HADOOP_JUMBO_RETCOUNTER + $? ))
fi

exit ${HADOOP_JUMBO_RETCOUNTER}

3、关闭Hadoop所有服务★★★

1. 命令使用

#关闭历史记录服务
mapred --daemon stop historyserver
#关闭yarn服务
stop-yarn.sh
#------------------------------------------------------------------
Stopping nodemanagers
Last login: Wed Dec 29 18:55:34 CST 2021 from 192.168.50.1 on pts/0
Stopping resourcemanager
Last login: Wed Dec 29 18:56:30 CST 2021 on pts/0
#------------------------------------------------------------------
#关闭HDFS服务
stop-dfs.sh
#------------------------------------------------
Stopping namenodes on [single01]
Last login: Wed Dec 29 18:56:32 CST 2021 on pts/0
Stopping datanodes
Last login: Wed Dec 29 18:57:13 CST 2021 on pts/0
Stopping secondary namenodes [single01]
Last login: Wed Dec 29 18:57:14 CST 2021 on pts/0
#------------------------------------------------

2.stop-dfs.sh

function hadoop_usage
{
  echo "Usage: stop-dfs.sh"
}
# 获取执行环境
this="${BASH_SOURCE-$0}"
#获取文件路径
bin=$(cd -P -- "$(dirname -- "${this}")" >/dev/null && pwd -P)

# 获取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}"
# 定义失败信息输出
HADOOP_NEW_CONFIG=true
if [[ -f "${HADOOP_LIBEXEC_DIR}/hdfs-config.sh" ]]; then
  . "${HADOOP_LIBEXEC_DIR}/hdfs-config.sh"
else
  echo "ERROR: Cannot execute ${HADOOP_LIBEXEC_DIR}/hdfs-config.sh." 2>&1
  exit 1
fi

#---------------------------------------------------------
# 关闭namenodes

NAMENODES=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -namenodes 2>/dev/null)

if [[ -z "${NAMENODES}" ]]; then
  NAMENODES=$(hostname)
fi
#NameNode关闭信息输出
echo "Stopping namenodes on [${NAMENODES}]"
  #执行NameNode关闭
  hadoop_uservar_su hdfs namenode "${HADOOP_HDFS_HOME}/bin/hdfs" \
    --workers \
    --config "${HADOOP_CONF_DIR}" \
    --hostnames "${NAMENODES}" \
    --daemon stop \
    namenode

#---------------------------------------------------------
# datanodes (using default workers file)
#关闭DataNode信息提示信息
echo "Stopping datanodes"

hadoop_uservar_su hdfs datanode "${HADOOP_HDFS_HOME}/bin/hdfs" \
  --workers \
  --config "${HADOOP_CONF_DIR}" \
  --daemon stop \
  datanode

#---------------------------------------------------------
# 关闭secondary namenodes

SECONDARY_NAMENODES=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -secondarynamenodes 2>/dev/null)

if [[ "${SECONDARY_NAMENODES}" == "0.0.0.0" ]]; then
  SECONDARY_NAMENODES=$(hostname)
fi

if [[ -n "${SECONDARY_NAMENODES}" ]]; then
  #提示信息输出
  echo "Stopping secondary namenodes [${SECONDARY_NAMENODES}]"
  #关闭secondary namenodes
  hadoop_uservar_su hdfs secondarynamenode "${HADOOP_HDFS_HOME}/bin/hdfs" \
    --workers \
    --config "${HADOOP_CONF_DIR}" \
    --hostnames "${SECONDARY_NAMENODES}" \
    --daemon stop \
    secondarynamenode
fi

#---------------------------------------------------------
#  quorumjournal nodes 
# 关闭journal node
JOURNAL_NODES=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -journalNodes 2>&-)

if [[ "${#JOURNAL_NODES}" != 0 ]]; then
  #提示信息输出
  echo "Stopping journal nodes [${JOURNAL_NODES}]"
  #执行关闭journal node
  hadoop_uservar_su hdfs journalnode "${HADOOP_HDFS_HOME}/bin/hdfs" \
    --workers \
    --config "${HADOOP_CONF_DIR}" \
    --hostnames "${JOURNAL_NODES}" \
    --daemon stop \
    journalnode
fi

#---------------------------------------------------------
# # 如果在高可用状态启动失败进行Zookeeper失败重启
AUTOHA_ENABLED=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey dfs.ha.automatic-failover.enabled | tr '[:upper:]' '[:lower:]')
if [[ "${AUTOHA_ENABLED}" = "true" ]]; then
  echo "Stopping ZK Failover Controllers on NN hosts [${NAMENODES}]"

  hadoop_uservar_su hdfs zkfc "${HADOOP_HDFS_HOME}/bin/hdfs" \
    --workers \
    --config "${HADOOP_CONF_DIR}" \
    --hostnames "${NAMENODES}" \
    --daemon stop \
    zkfc
fi

3.stop-yarn.sh

function hadoop_usage
{
  hadoop_generate_usage "${MYNAME}" false
}
# 获取执行环境
MYNAME="${BASH_SOURCE-$0}"

bin=$(cd -P -- "$(dirname -- "${MYNAME}")" >/dev/null && pwd -P)

# 获取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}"
# 定义失败信息输出
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

# 关闭nodemanager信息输出
echo "Stopping nodemanagers"
# 执行关闭nodemanager
hadoop_uservar_su yarn nodemanager "${HADOOP_YARN_HOME}/bin/yarn" \
    --config "${HADOOP_CONF_DIR}" \
    --workers \
    --daemon stop \
    nodemanager

# 关闭resourceManager
HARM=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey yarn.resourcemanager.ha.enabled 2>&-)
if [[ ${HARM} = "false" ]]; then
  # 关闭resourceManager信息输出
  echo "Stopping resourcemanager"
  # 执行关闭resourceManager
  hadoop_uservar_su yarn resourcemanager "${HADOOP_YARN_HOME}/bin/yarn" \
      --config "${HADOOP_CONF_DIR}" \
      --daemon stop \
      resourcemanager
else
  logicals=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey yarn.resourcemanager.ha.rm-ids 2>&-)
  logicals=${logicals//,/ }
  for id in ${logicals}
  do
      rmhost=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey "yarn.resourcemanager.hostname.${id}" 2>&-)
      RMHOSTS="${RMHOSTS} ${rmhost}"
  done
  echo "Stopping resourcemanagers on [${RMHOSTS}]"
  hadoop_uservar_su yarn resourcemanager "${HADOOP_YARN_HOME}/bin/yarn" \
      --config "${HADOOP_CONF_DIR}" \
      --daemon stop \
      --workers \
      --hostnames "${RMHOSTS}" \
      resourcemanager
fi

# 关闭 proxyserver
PROXYSERVER=$("${HADOOP_HDFS_HOME}/bin/hdfs" getconf -confKey  yarn.web-proxy.address 2>&- | cut -f1 -d:)
if [[ -n ${PROXYSERVER} ]]; then
  # 关闭 proxyserver提示信息输出
  echo "Stopping proxy server [${PROXYSERVER}]"
  # 执行关闭 proxyserver
  hadoop_uservar_su yarn proxyserver "${HADOOP_YARN_HOME}/bin/yarn" \
      --config "${HADOOP_CONF_DIR}" \
      --workers \
      --hostnames "${PROXYSERVER}" \
      --daemon stop \
      proxyserver
fi

hadoop_588">4、利用浏览器查看hadoop状态

1.访问HDFS控制页面

主机IP地址：9870

#访问格式
host：9870
#例程
192.168.50.102:9870

2.访问历史服务（historyserver）

主机IP地址：19888

#访问格式
host：19888
#例程
192.168.50.102:19888

3.进程监控（application monitoring）

主机IP地址：8088

#访问格式
host：8088
#例程
192.168.50.102:8088

http://www.niftyadmin.cn/n/1616085.html

相关文章

正正得负？音效合成应用Talkapella

正正得负？音效合成应用Talkapella

小编曾经在上周的《iOS语音应用盘点》介绍过 一款将录音进行变声效果转换的应用“Voice Morph Pro”，这次介绍的这款Talkapella则是一款和它很接近的应用，你可以在这款应用里录下你的声音然后选择音轨混合出各种效果的音乐，看起来是挺酷的应用…
阅读更多...
HDOJ 2032

HDOJ 2032

Problem Description 还记得中学时候学过的杨辉三角吗？具体的定义这里不再描述，你可以参考以下的图形： 1 1 1 1 2 1 1 3 3 1 1 4 6 4 1 1 5 10 10 5 1 Input 输入数据包含多个测试实例，每个测试实例的输入只包含一个正整数n&…
阅读更多...
hadoop的HDFS的shell命令大全（一篇文章就够了）

hadoop的HDFS的shell命令大全（一篇文章就够了）

文章目录HDFS的shell命令1、安全模式1.查看安全模式状态2.手工开启安全模式状态3.手工关闭安全模式状态2、文件操作指令1.查看文件目录2.查看文件夹情况3.文件操作4.上传文件5、获取文件6.查看文件内容7.创建目录8.修改副本数量9.创建空白文件（不推荐使用&#xff0…
阅读更多...
HDOJ 2099

HDOJ 2099

Problem Description 一个整数&#xff0c;只知道前几位&#xff0c;不知道末二位&#xff0c;被另一个整数除尽了&#xff0c;那么该数的末二位该是什么呢&#xff1f; Input 输入数据有若干组&#xff0c;每组数据包含二个整数a&#xff0c;b&#xff08;0<a<10000, 1…
阅读更多...
SPB Shell 3D：打造最酷3D效果的Android界面

SPB Shell 3D：打造最酷3D效果的Android界面

Android的魅力在于其开放性&#xff0c;与iPhone的千人一面相比&#xff0c;Android用户则可以用各种应用装扮爱机&#xff0c;彰显个性&#xff0c;其中能让用户自定义系统界面的应用&#xff0c;比如ADW、LauncherPro、Go桌面更是大受欢迎。不过&#xff0c;说起这类应用&…
阅读更多...
HDFS的NameNode节点信息管理（元数据）

HDFS的NameNode节点信息管理（元数据）

文章目录HDFS的NameNode信息1、NameNode的信息存放地址2、NameNode节点数据查看3、fsimage文件4、edits文件HDFS的NameNode信息 1、NameNode的信息存放地址 NameNode存储DataNode的元数据&#xff0c;NameNode主要是用于维护DataNode信息。它存储在hadoop文件夹下data/dfs/na…
阅读更多...
创业需谨慎：减少摩擦，打造快乐体验

创业需谨慎：减少摩擦，打造快乐体验

编者注&#xff1a;本文原作者为Onesheet和ArtistData的创始人 Brenden Mulligan。编译时文章内容有轻微改动。 当问及对初创公司有何建议时&#xff0c;最近我脑袋里反复浮现一个主题——减少摩擦。 减少产品摩擦带来的直接效益是&#xff0c;减少用户挫败感&#xff0c;增加用…
阅读更多...
HDOJ 2098

HDOJ 2098

分拆素数和 Problem Description 把一个偶数拆成两个不同素数的和&#xff0c;有几种拆法呢&#xff1f; Input 输入包含一些正的偶数&#xff0c;其值不会超过10000&#xff0c;个数不会超过500&#xff0c;若遇0&#xff0c;则结束。 Output 对应每个偶数&#xff0c;输出…
阅读更多...
最新文章

Copyright @ 2022~2023