四、ElasticSearch节点启动

节点启动流程

• 解析命令行和配置文件参数
• 检查JVM、操作系统环境
• 初始化内部模块
• 启动子模块和keepalive

1、启动脚本

source "`dirname "$0"`"/elasticsearch-env

ES_JVM_OPTIONS="$ES_PATH_CONF"/jvm.options
JVM_OPTIONS=`"$JAVA" -cp "$ES_CLASSPATH" org.elasticsearch.tools.launchers.JvmOptionsParser "$ES_JVM_OPTIONS"`
ES_JAVA_OPTS="${JVM_OPTIONS//\$\{ES_TMPDIR\}/$ES_TMPDIR} $ES_JAVA_OPTS"

cd "$ES_HOME"
# manual parsing to find out, if process should be detached
if ! echo $* | grep -E '(^-d |-d$| -d |--daemonize$|--daemonize )' > /dev/null; then
  exec \
    "$JAVA" \
    $ES_JAVA_OPTS \
    -Des.path.home="$ES_HOME" \
    -Des.path.conf="$ES_PATH_CONF" \
    -Des.distribution.flavor="$ES_DISTRIBUTION_FLAVOR" \
    -Des.distribution.type="$ES_DISTRIBUTION_TYPE" \
    -cp "$ES_CLASSPATH" \
    org.elasticsearch.bootstrap.Elasticsearch \
    "$@"
else
  exec \
    "$JAVA" \
    $ES_JAVA_OPTS \
    -Des.path.home="$ES_HOME" \
    -Des.path.conf="$ES_PATH_CONF" \
    -Des.distribution.flavor="$ES_DISTRIBUTION_FLAVOR" \
    -Des.distribution.type="$ES_DISTRIBUTION_TYPE" \
    -cp "$ES_CLASSPATH" \
    org.elasticsearch.bootstrap.Elasticsearch \
    "$@" \
    <&- &
  retval=$?
  pid=$!
  [ $retval -eq 0 ] || exit $retval
  if [ ! -z "$ES_STARTUP_SLEEP_TIME" ]; then
    sleep $ES_STARTUP_SLEEP_TIME
  fi
  if ! ps -p $pid > /dev/null ; then
    exit 1
  fi
  exit 0
fi

exit $?

2、解析命令行参数和配置文件

jvm.options
elasticsearch.yml
log4j2.properties

3、加载安全配置

elasticsearch.keystore

4、检查内部环境

5、检测外部环境

6、启动内部模块

7、启动keepalive线程