Spark启动流程（Standalone）-分析

清疚 2023-06-25 04:56 82阅读 0赞

![E5_9B_BE_E7_89_87-2.png][]

1、start-all.sh脚本，实际上执行java -cp Master 和 java -cp Worker

2、Master 启动时首先穿件一个RpcEnv对象，负责管理所有通信逻辑

3、Master 通信RpcEnv对象创建一个Endpoint，Master就是一个Endpoint，Worker可以与其进行通信

4、Worker启动时也是创建一个RpcEnv对象

5、Worker通过RpcEnv对象创建一个Endpoint

6、Worker 通过RpcEnv对象建立到Master的连接 ，获取到一个RpcEndpointRef对象，通过该对象可以与Master通信

7、Worker向Master注册，注册内容包括主机名、端口、CPU core数量、内存数量

8、Master接收到worker的注册，将注册信息维护在内存中的table中，其中还包含了一个到worker的RpcEndpointRef对象引用

9、Master回复Worker已经接收到注册，告知Worker已经注册成功

10、Worker端收到成功注册相应后，开始周期性向Master发送心跳

## 1、start-master.sh Master 启动脚本分析 ##

start-master.sh

1 //读取SPARK_HOME
     2 if [ -z "${SPARK_HOME}" ]; then
     3   export SPARK_HOME="$(cd "`dirname "$0"`"/..; pwd)"
     4 fi
     5 
     6 # NOTE: This exact class name is matched downstream by SparkSubmit.
     7 # Any changes need to be reflected there.
     8 CLASS="org.apache.spark.deploy.master.Master"
     9 
    10 if [[ "$@" = *--help ]] || [[ "$@" = *-h ]]; then
    11   echo "Usage: ./sbin/start-master.sh [options]"
    12   pattern="Usage:"
    13   pattern+="\|Using Spark's default log4j profile:"
    14   pattern+="\|Registered signal handlers for"
    15 
    16   "${SPARK_HOME}"/bin/spark-class $CLASS --help 2>&1 | grep -v "$pattern" 1>&2
    17   exit 1
    18 fi
    19 
    20 ORIGINAL_ARGS="$@"
    21 
    22 . "${SPARK_HOME}/sbin/spark-config.sh"
    23 
    24 . "${SPARK_HOME}/bin/load-spark-env.sh"
    25 
    26 if [ "$SPARK_MASTER_PORT" = "" ]; then
    27   SPARK_MASTER_PORT=7077
    28 fi
    29 
    30 if [ "$SPARK_MASTER_HOST" = "" ]; then
    31   case `uname` in
    32       (SunOS)
    33       SPARK_MASTER_HOST="`/usr/sbin/check-hostname | awk '{print $NF}'`"
    34       ;;
    35       (*)
    36       SPARK_MASTER_HOST="`hostname -f`"
    37       ;;
    38   esac
    39 fi
    40 
    41 if [ "$SPARK_MASTER_WEBUI_PORT" = "" ]; then
    42   SPARK_MASTER_WEBUI_PORT=8080
    43 fi
    44 //调用spark-daemon.sh执行
    45 "${SPARK_HOME}/sbin"/spark-daemon.sh start $CLASS 1 \
    46   --host $SPARK_MASTER_HOST --port $SPARK_MASTER_PORT --webui-port $SPARK_MASTER_WEBUI_PORT \
    47   $ORIGINAL_ARGS

spark-daemon.sh

1 ...
     2 
     3 execute_command() {
     4   if [ -z ${SPARK_NO_DAEMONIZE+set} ]; then
     5      # 最终以后台守护进程的方式启动 Master
     6       nohup -- "$@" >> $log 2>&1 < /dev/null &
     7       newpid="$!"
     8 
     9       echo "$newpid" > "$pid"
    10 
    11       # Poll for up to 5 seconds for the java process to start
    12       for i in {1..10}
    13       do
    14         if [[ $(ps -p "$newpid" -o comm=) =~ "java" ]]; then
    15            break
    16         fi
    17         sleep 0.5
    18       done
    19 
    20       sleep 2
    21       # Check if the process has died; in that case we'll tail the log so the user can see
    22       if [[ ! $(ps -p "$newpid" -o comm=) =~ "java" ]]; then
    23         echo "failed to launch: $@"
    24         tail -2 "$log" | sed 's/^/  /'
    25         echo "full log in $log"
    26       fi
    27   else
    28       "$@"
    29   fi
    30 }
    31 
    32 ...

启动类

1 /opt/module/spark-standalone/bin/spark-class       org.apache.spark.deploy.master.Master 
    2             --host hadoop201 
    3             --port 7077 
    4             --webui-port 8080

bin/spark-class启动命令：

1  /opt/module/jdk1.8.0_172/bin/java 
    2         -cp /opt/module/spark-standalone/conf/:/opt/module/spark-standalone/jars/* 
    3         -Xmx1g org.apache.spark.deploy.master.Master 
    4         --host hadoop201 
    5         --port 7077 
    6         --webui-port 8080

[E5_9B_BE_E7_89_87-2.png]: http://47.112.223.94/wp-content/uploads/2019/12/%E5%9B%BE%E7%89%87-2.png