elasticsearch指定jdk

1.修改/elasticsearch-7.8.0/bin目录下elasticsearch配置文件，添加如下配置

#配置自己的jdk11
export JAVA_HOME=/opt/elasticsearch-7.8.0/jdk
export PATH=$JAVA_HOME/bin:$PATH

#添加jdk判断
if [ -x "$JAVA_HOME/bin/java" ]; then
	        JAVA="/opt/elasticsearch-7.8.0/jdk/bin/java"
else
		        JAVA=`which java`
fi

2.完整elasticsearch配置文件

#!/bin/bash

# CONTROLLING STARTUP:
#
# This script relies on a few environment variables to determine startup
# behavior, those variables are:
#
#   ES_PATH_CONF -- Path to config directory
#   ES_JAVA_OPTS -- External Java Opts on top of the defaults set
#
# Optionally, exact memory values can be set using the `ES_JAVA_OPTS`. Example
# values are "512m", and "10g".
#
#   ES_JAVA_OPTS="-Xms8g -Xmx8g" ./bin/elasticsearch

#配置自己的jdk11
export JAVA_HOME=/opt/elasticsearch-7.8.0/jdk
export PATH=$JAVA_HOME/bin:$PATH

#添加jdk判断
if [ -x "$JAVA_HOME/bin/java" ]; then
	        JAVA="/opt/elasticsearch-7.8.0/jdk/bin/java"
else
		        JAVA=`which java`
fi

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

CHECK_KEYSTORE=true
DAEMONIZE=false
for option in "$@"; do
  case "$option" in
    -h|--help|-V|--version)
      CHECK_KEYSTORE=false
      ;;
    -d|--daemonize)
      DAEMONIZE=true
      ;;
  esac
done

if [ -z "$ES_TMPDIR" ]; then
  ES_TMPDIR=`"$JAVA" "$XSHARE" -cp "$ES_CLASSPATH" org.elasticsearch.tools.launchers.TempDirectory`
fi

# get keystore password before setting java options to avoid
# conflicting GC configurations for the keystore tools
unset KEYSTORE_PASSWORD
KEYSTORE_PASSWORD=
if [[ $CHECK_KEYSTORE = true ]] \
    && bin/elasticsearch-keystore has-passwd --silent
then
  if ! read -s -r -p "Elasticsearch keystore password: " KEYSTORE_PASSWORD ; then
    echo "Failed to read keystore password on console" 1>&2
    exit 1
  fi
fi

# The JVM options parser produces the final JVM options to start Elasticsearch.
# It does this by incorporating JVM options in the following way:
#   - first, system JVM options are applied (these are hardcoded options in the
#     parser)
#   - second, JVM options are read from jvm.options and jvm.options.d/*.options
#   - third, JVM options from ES_JAVA_OPTS are applied
#   - fourth, ergonomic JVM options are applied
ES_JAVA_OPTS=`export ES_TMPDIR; "$JAVA" "$XSHARE" -cp "$ES_CLASSPATH" org.elasticsearch.tools.launchers.JvmOptionsParser "$ES_PATH_CONF"`
# manual parsing to find out, if process should be detached
if [[ $DAEMONIZE = false ]]; then
  exec \
    "$JAVA" \
    "$XSHARE" \
    $ES_JAVA_OPTS \
    -Des.path.home="$ES_HOME" \
    -Des.path.conf="$ES_PATH_CONF" \
    -Des.distribution.flavor="$ES_DISTRIBUTION_FLAVOR" \
    -Des.distribution.type="$ES_DISTRIBUTION_TYPE" \
    -Des.bundled_jdk="$ES_BUNDLED_JDK" \
    -cp "$ES_CLASSPATH" \
    org.elasticsearch.bootstrap.Elasticsearch \
    "$@" <<<"$KEYSTORE_PASSWORD"
else
  exec \
    "$JAVA" \
    "$XSHARE" \
    $ES_JAVA_OPTS \
    -Des.path.home="$ES_HOME" \
    -Des.path.conf="$ES_PATH_CONF" \
    -Des.distribution.flavor="$ES_DISTRIBUTION_FLAVOR" \
    -Des.distribution.type="$ES_DISTRIBUTION_TYPE" \
    -Des.bundled_jdk="$ES_BUNDLED_JDK" \
    -cp "$ES_CLASSPATH" \
    org.elasticsearch.bootstrap.Elasticsearch \
    "$@" \
    <<<"$KEYSTORE_PASSWORD" &
  retval=$?
  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 $?

3.创建es账号并赋权

由于es新版本不允许使用root启动，需要重新创建账号。

useradd es  #创建用户es
passwd es   #给已创建的用户es设置密码
chown -R es elasticsearch-7.8.0/ #文件赋权

4.切换账户并启动elasticsearch。

su es  #切换到es
cd elasticsearch-7.8.0/bin #进去es的bin目录下
./elasticsearch -d   #后台启动

如果启动出现elasticsearch-env << 符号异常，修改elasticsearch-env文件，第112行：

 done < < <(env)  修改为   done <<<'env'