问题

使用netstat -tunlp命令发现，除了zookeeper占用的2181端口以外还有一个随机端口和8080端口启用了。

原因

1、zookeeper启动后默认会开一个端口用来支持jmx调用，所以导致开启了非预期的随机端口。
2、zookeeper 中有个内嵌的管理控制台是通过jetty启动，会占用8080 端口。

方法1

（在使用zookeeper 3.6之后的版本，开启服务器，zk会自动占用8080端口，而后端服务器大部分都需要使用8080端口，因此需要zk的配置文件即可。）

在zk conf目录里面，修改zoo.cfg，在其中加上：

admin.serverPort 默认占8080端口

admin.serverPort=自己定一个端口
重启zk服务器，即可。

方法2

如果不用admin端口，在启动脚本加上"-Dzookeeper.admin.enableServer=false"

重启即可

修改后的启动脚本/home/apache-zookeeper-3.6.1-bin/bin/zkServer.sh

#!/usr/bin/env bash

# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

#
# If this scripted is run out of /usr/bin or some other system bin directory
# it should be linked to and not copied. Things like java jar files are found
# relative to the canonical path of this script.
#

# use POSIX interface, symlink is followed automatically
ZOOBIN="${BASH_SOURCE-$0}"
ZOOBIN="$(dirname "${ZOOBIN}")"
ZOOBINDIR="$(cd "${ZOOBIN}"; pwd)"

if [ -e "$ZOOBIN/../libexec/zkEnv.sh" ]; then
  . "$ZOOBINDIR"/../libexec/zkEnv.sh
else
  . "$ZOOBINDIR"/zkEnv.sh
fi

# See the following page for extensive details on setting
# up the JVM to accept JMX remote management:
# http://java.sun.com/javase/6/docs/technotes/guides/management/agent.html
# by default we allow local JMX connections
if [ "x$JMXLOCALONLY" = "x" ]
then
    JMXLOCALONLY=false
fi

if [ "x$JMXDISABLE" = "x" ] || [ "$JMXDISABLE" = 'false' ]
then
  echo "ZooKeeper JMX enabled by default" >&2
  if [ "x$JMXPORT" = "x" ]
  then
    # for some reason these two options are necessary on jdk6 on Ubuntu
    #   accord to the docs they are not necessary, but otw jconsole cannot
    #   do a local attach
    ZOOMAIN="-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.local.only=$JMXLOCALONLY org.apache.zookeeper.server.quorum.QuorumPeerMain"
  else
    if [ "x$JMXAUTH" = "x" ]
    then
      JMXAUTH=false
    fi
    if [ "x$JMXSSL" = "x" ]
    then
      JMXSSL=false
    fi
    if [ "x$JMXLOG4J" = "x" ]
    then
      JMXLOG4J=true
    fi
    echo "ZooKeeper remote JMX Port set to $JMXPORT" >&2
    echo "ZooKeeper remote JMX authenticate set to $JMXAUTH" >&2
    echo "ZooKeeper remote JMX ssl set to $JMXSSL" >&2
    echo "ZooKeeper remote JMX log4j set to $JMXLOG4J" >&2
    ZOOMAIN="-Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=$JMXPORT -Dcom.sun.management.jmxremote.authenticate=$JMXAUTH -Dcom.sun.management.jmxremote.ssl=$JMXSSL -Dzookeeper.jmx.log4j.disable=$JMXLOG4J org.apache.zookeeper.server.quorum.QuorumPeerMain"
  fi
else
    echo "JMX disabled by user request" >&2
    ZOOMAIN="org.apache.zookeeper.server.quorum.QuorumPeerMain"
fi

if [ "x$SERVER_JVMFLAGS" != "x" ]
then
    JVMFLAGS="$SERVER_JVMFLAGS $JVMFLAGS"
fi

if [ "x$2" != "x" ]
then
    ZOOCFG="$ZOOCFGDIR/$2"
fi

# if we give a more complicated path to the config, don't screw around in $ZOOCFGDIR
if [ "x$(dirname "$ZOOCFG")" != "x$ZOOCFGDIR" ]
then
    ZOOCFG="$2"
fi

if $cygwin
then
    ZOOCFG=`cygpath -wp "$ZOOCFG"`
    # cygwin has a "kill" in the shell itself, gets confused
    KILL=/bin/kill
else
    KILL=kill
fi

echo "Using config: $ZOOCFG" >&2

case "$OSTYPE" in
*solaris*)
  GREP=/usr/xpg4/bin/grep
  ;;
*)
  GREP=grep
  ;;
esac
ZOO_DATADIR="$($GREP "^[[:space:]]*dataDir" "$ZOOCFG" | sed -e 's/.*=//')"
ZOO_DATADIR="$(echo -e "${ZOO_DATADIR}" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')"
ZOO_DATALOGDIR="$($GREP "^[[:space:]]*dataLogDir" "$ZOOCFG" | sed -e 's/.*=//')"

# iff autocreate is turned off and the datadirs don't exist fail
# immediately as we can't create the PID file, etc..., anyway.
if [ -n "$ZOO_DATADIR_AUTOCREATE_DISABLE" ]; then
    if [ ! -d "$ZOO_DATADIR/version-2" ]; then
        echo "ZooKeeper data directory is missing at $ZOO_DATADIR fix the path or run initialize"
        exit 1
    fi

    if [ -n "$ZOO_DATALOGDIR" ] && [ ! -d "$ZOO_DATALOGDIR/version-2" ]; then
        echo "ZooKeeper txnlog directory is missing at $ZOO_DATALOGDIR fix the path or run initialize"
        exit 1
    fi
    ZOO_DATADIR_AUTOCREATE="-Dzookeeper.datadir.autocreate=false"
fi

if [ -z "$ZOOPIDFILE" ]; then
    if [ ! -d "$ZOO_DATADIR" ]; then
        mkdir -p "$ZOO_DATADIR"
    fi
    ZOOPIDFILE="$ZOO_DATADIR/zookeeper_server.pid"
else
    # ensure it exists, otw stop will fail
    mkdir -p "$(dirname "$ZOOPIDFILE")"
fi

if [ ! -w "$ZOO_LOG_DIR" ] ; then
mkdir -p "$ZOO_LOG_DIR"
fi

ZOO_LOG_FILE=zookeeper-$USER-server-$HOSTNAME.log
_ZOO_DAEMON_OUT="$ZOO_LOG_DIR/zookeeper-$USER-server-$HOSTNAME.out"

case $1 in
start)
    echo  -n "Starting zookeeper ... "
    if [ -f "$ZOOPIDFILE" ]; then
      if kill -0 `cat "$ZOOPIDFILE"` > /dev/null 2>&1; then
         echo $command already running as process `cat "$ZOOPIDFILE"`.
         exit 1
      fi
    fi
    nohup "$JAVA" $ZOO_DATADIR_AUTOCREATE "-Dzookeeper.log.dir=${ZOO_LOG_DIR}" \
    "-Dzookeeper.log.file=${ZOO_LOG_FILE}" "-Dzookeeper.root.logger=${ZOO_LOG4J_PROP}" "-Dzookeeper.admin.enableServer=false" \
    -XX:+HeapDumpOnOutOfMemoryError -XX:OnOutOfMemoryError='kill -9 %p' \
    -cp "$CLASSPATH" $JVMFLAGS $ZOOMAIN "$ZOOCFG" > "$_ZOO_DAEMON_OUT" 2>&1 < /dev/null &
    if [ $? -eq 0 ]
    then
      case "$OSTYPE" in
      *solaris*)
        /bin/echo "${!}\\c" > "$ZOOPIDFILE"
        ;;
      *)
        /bin/echo -n $! > "$ZOOPIDFILE"
        ;;
      esac
      if [ $? -eq 0 ];
      then
        sleep 1
        pid=$(cat "${ZOOPIDFILE}")
        if ps -p "${pid}" > /dev/null 2>&1; then
          echo STARTED
        else
          echo FAILED TO START
          exit 1
        fi
      else
        echo FAILED TO WRITE PID
        exit 1
      fi
    else
      echo SERVER DID NOT START
      exit 1
    fi
    ;;
start-foreground)
    ZOO_CMD=(exec "$JAVA")
    if [ "${ZOO_NOEXEC}" != "" ]; then
      ZOO_CMD=("$JAVA")
    fi
    "${ZOO_CMD[@]}" $ZOO_DATADIR_AUTOCREATE "-Dzookeeper.log.dir=${ZOO_LOG_DIR}" \
    "-Dzookeeper.log.file=${ZOO_LOG_FILE}" "-Dzookeeper.root.logger=${ZOO_LOG4J_PROP}" \
    -XX:+HeapDumpOnOutOfMemoryError -XX:OnOutOfMemoryError='kill -9 %p' \
    -cp "$CLASSPATH" $JVMFLAGS $ZOOMAIN "$ZOOCFG"
    ;;
print-cmd)
    echo "\"$JAVA\" $ZOO_DATADIR_AUTOCREATE -Dzookeeper.log.dir=\"${ZOO_LOG_DIR}\" \
    -Dzookeeper.log.file=\"${ZOO_LOG_FILE}\" -Dzookeeper.root.logger=\"${ZOO_LOG4J_PROP}\" \
    -XX:+HeapDumpOnOutOfMemoryError -XX:OnOutOfMemoryError='kill -9 %p' \
    -cp \"$CLASSPATH\" $JVMFLAGS $ZOOMAIN \"$ZOOCFG\" > \"$_ZOO_DAEMON_OUT\" 2>&1 < /dev/null"
    ;;
stop)
    echo -n "Stopping zookeeper ... "
    if [ ! -f "$ZOOPIDFILE" ]
    then
      echo "no zookeeper to stop (could not find file $ZOOPIDFILE)"
    else
      $KILL $(cat "$ZOOPIDFILE")
      rm "$ZOOPIDFILE"
      sleep 1
      echo STOPPED
    fi
    exit 0
    ;;
version)
    ZOOMAIN=org.apache.zookeeper.version.VersionInfoMain
    $JAVA -cp "$CLASSPATH" $ZOOMAIN 2> /dev/null
    ;;
restart)
    shift
    "$0" stop ${@}
    sleep 3
    "$0" start ${@}
    ;;
status)
    # -q is necessary on some versions of linux where nc returns too quickly, and no stat result is output
    clientPortAddress=`$GREP "^[[:space:]]*clientPortAddress[^[:alpha:]]" "$ZOOCFG" | sed -e 's/.*=//'`
    if ! [ $clientPortAddress ]
    then
    clientPortAddress="localhost"
    fi
    clientPort=`$GREP "^[[:space:]]*clientPort[^[:alpha:]]" "$ZOOCFG" | sed -e 's/.*=//'`
    if ! [[ "$clientPort"  =~ ^[0-9]+$ ]]
    then
       dataDir=`$GREP "^[[:space:]]*dataDir" "$ZOOCFG" | sed -e 's/.*=//'`
       myid=`cat "$dataDir/myid"`
       if ! [[ "$myid" =~ ^[0-9]+$ ]] ; then
         echo "clientPort not found and myid could not be determined. Terminating."
         exit 1
       fi
       clientPortAndAddress=`$GREP "^[[:space:]]*server.$myid=.*;.*" "$ZOOCFG" | sed -e 's/.*=//' | sed -e 's/.*;//'`
       if [ ! "$clientPortAndAddress" ] ; then
           echo "Client port not found in static config file. Looking in dynamic config file."
           dynamicConfigFile=`$GREP "^[[:space:]]*dynamicConfigFile" "$ZOOCFG" | sed -e 's/.*=//'`
           clientPortAndAddress=`$GREP "^[[:space:]]*server.$myid=.*;.*" "$dynamicConfigFile" | sed -e 's/.*=//' | sed -e 's/.*;//'`
       fi
       if [ ! "$clientPortAndAddress" ] ; then
          echo "Client port not found. Terminating."
          exit 1
       fi
       if [[ "$clientPortAndAddress" =~ ^.*:[0-9]+ ]] ; then
          clientPortAddress=`echo "$clientPortAndAddress" | sed -e 's/:.*//'`
       fi
       clientPort=`echo "$clientPortAndAddress" | sed -e 's/.*://'`
       if [ ! "$clientPort" ] ; then
          echo "Client port not found. Terminating."
          exit 1
       fi
    fi
    echo "Client port found: $clientPort. Client address: $clientPortAddress."
    STAT=`"$JAVA" "-Dzookeeper.log.dir=${ZOO_LOG_DIR}" "-Dzookeeper.root.logger=${ZOO_LOG4J_PROP}" "-Dzookeeper.log.file=${ZOO_LOG_FILE}" \
             -cp "$CLASSPATH" $JVMFLAGS org.apache.zookeeper.client.FourLetterWordMain \
             $clientPortAddress $clientPort srvr 2> /dev/null    \
          | $GREP Mode`
    if [ "x$STAT" = "x" ]
    then
        echo "Error contacting service. It is probably not running."
        exit 1
    else
        echo $STAT
        exit 0
    fi
    ;;
*)
    echo "Usage: $0 [--config <conf-dir>] {start|start-foreground|stop|version|restart|status|print-cmd}" >&2

esac