如何实现 Tomcat 服务双机热备？

1. 规划

1.1服务器环境规划

负载服务器master及WEB服务器1真实IP：10.10.195.53

负载服务器backup及WEB服务器2真实IP：10.10.195.190

负载服务器虚拟ip：10.10.195.212

1.2 软件环境规划

操作系统：Red Hat Enterprise Linux Server release 5.6 (Tikanga)

keepalived：keepalived-1.2.19

Java：jdk-1.7.0_79

Tomcat：apache-tomcat-7.0.64

2. 负载服务器配置

这里只叙述如何安装配置keepalived，至于java以及tomcat的安装及配置，这里不赘述。

2.1 安装keepalived

[~]tar -zxvf keepalived-1.2.19.tar.gz

[~] cd keepalived-1.2.19

[keepalived-1.2.19] ./configure --prefix=/usr/local/keepalived --disable-fwmark

#(如果直接输入./configure有可能报错：configure:error: No SO_MARK declaration in headers)

[keepalived-1.2.19] make

[keepalived-1.2.19] make install

2.2 配置keepalived服务

[keepalived-1.2.19] cp /usr/local/keepalived/sbin/keepalived /usr/sbin/

[keepalived-1.2.19] cp /usr/local/keepalived/etc/sysconfig/keepalived /etc/sysconfig/

[keepalived-1.2.19] cp /usr/local/keepalived/etc/rc.d/init.d/keepalived /etc/init.d/

[keepalived-1.2.19] mkdir /etc/keepalived

[keepalived-1.2.19] cp /usr/local/keepalived/etc/keepalived/keepalived.conf/etc/keepalived/

[keepalived-1.2.19] chkconfig --add keepalived

[keepalived-1.2.19] chkconfig keepalived on

重启\启动\关闭\查看状态keepalived

service keepalived restart

service keepalived start

service keepalived stop

service keepalived status

2.3 配置keepalived.conf文件

[~]mv /etc/keepalived/keepalived.conf/etc/keepalived/keepalived.conf.bak

[~]vi /etc/keepalived//keepalived.conf

主备机的keepalived.conf文件大致相同，只是注意红色标注的地方。

主机配置：

global_defs {

router_id NodeA

}

vrrp_script chk_http_port {

script "/opt/tomcat.pid"

interval 5

weight 2

}

vrrp_instance VI_1 {

state MASTER

interface eth0

virtual_router_id 52

priority 150

advert_int 1

authentication {

auth_type PASS

auth_pass 1111

}

track_script {

chk_http_port

}

virtual_ipaddress {

10.10.195.212

}

}

备机配置：

global_defs {

router_id NodeB

}

vrrp_script chk_http_port {

script "/opt/tomcat.pid"

interval 5

weight 2

}

vrrp_instance VI_1 {

state BACKUP

interface eth0

virtual_router_id 52

priority 100

advert_int 1

authentication {

auth_type PASS

auth_pass 1111

}

track_script {

chk_http_port

}

virtual_ipaddress {

10.10.195.212

}

}

2.4配置/opt/tomcat.pid

#!/bin/bash

#description: check tomcat service anddecide whether stop the keepalived or not

#edited by zzh: 2015-10-14

CATALINA_HOME=/users/shr/apache-tomcat-7.0.64

JAVA_HOME=/users/shr/util/JavaDir/jdk

export CATALINA_HOME

export JAVA_HOME

ps ax --width=1000 | grep"org.apache.catalina.startup.Bootstrap start" | grep -v"grep" | awk '{printf $1 " "}' | wc | awk '{print $2}' >tomcat_process_count.txt

read line < tomcat_process_count.txt  

start_tomcat=$CATALINA_HOME/bin/startup.sh

if [ ${line} -lt 1 ]

then

echo -n "===Starting tomcat===:"

${start_tomcat}

# :sudo service tomcat start

echo "===tomcat start ok.==="

sleep 3

# check the tomcat status.

ps ax --width=1000 | grep "org.apache.catalina.startup.Bootstrapstart" | grep -v "grep" | awk '{printf $1 " "}' | wc |awk '{print $2}' > tomcat_process_count.txt

read line2 < tomcat_process_count.txt  

if [ ${line2} -lt 1 ]

then

sudo service keepalived stop

fi

fi

rm tomcat_process_count.txt

#shell end.

3. 日志查看

3.1 正常启动

输入tail -f /var/log/messages查看启动keepalived日志：

（MASTER：10.10.195.53）

Sep 29 15:49:16 shr Keepalived[5536]:Starting Keepalived v1.2.19 (09/21,2015)

Sep 29 15:49:16 shrKeepalived_healthcheckers[5538]: Netlink reflector reports IP 10.10.195.53added

Sep 29 15:49:16 shrKeepalived_healthcheckers[5538]: Netlink reflector reports IP 10.10.195.53added

Sep 29 15:49:16 shrKeepalived_healthcheckers[5538]: Registering Kernel netlink reflector

Sep 29 15:49:16 shrKeepalived_healthcheckers[5538]: Registering Kernel netlink command channel

Sep 29 15:49:16 shrKeepalived_healthcheckers[5538]: Opening file'/etc/keepalived/keepalived.conf'.

Sep 29 15:49:16 shrKeepalived_healthcheckers[5538]: Configuration is using : 6572 Bytes

Sep 29 15:49:16 shr Keepalived[5537]:Starting Healthcheck child process, pid=5538

Sep 29 15:49:16 shr Keepalived_healthcheckers[5538]:Using LinkWatch kernel netlink reflector...

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:Netlink reflector reports IP 10.10.195.53 added

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:Netlink reflector reports IP 10.10.195.53 added

Sep 29 15:49:16 shr Keepalived[5537]:Starting VRRP child process, pid=5539

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:Registering Kernel netlink reflector

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:Registering Kernel netlink command channel

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:Registering gratuitous ARP shared channel

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:Opening file '/etc/keepalived/keepalived.conf'.

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:Configuration is using : 36541 Bytes

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:Using LinkWatch kernel netlink reflector...

Sep 29 15:49:16 shr Keepalived_vrrp[5539]:VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]

Sep 29 15:49:17 shr Keepalived_vrrp[5539]:VRRP_Instance(VI_1) Transition to MASTER STATE

Sep 29 15:49:17 shr Keepalived_vrrp[5539]:VRRP_Instance(VI_1) Received lower prio advert, forcing new election

Sep 29 15:49:18 shr Keepalived_vrrp[5539]:VRRP_Instance(VI_1) Entering MASTER STATE

Sep 29 15:49:18 shr Keepalived_vrrp[5539]:VRRP_Instance(VI_1) setting protocol VIPs.

Sep 29 15:49:18 shr Keepalived_vrrp[5539]:VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 10.10.195.212

Sep 29 15:49:18 shr Keepalived_vrrp[5539]:Netlink reflector reports IP 10.10.195.212 added

Sep 29 15:49:18 shrKeepalived_healthcheckers[5538]: Netlink reflector reports IP 10.10.195.212added

Sep 29 15:49:23 shr Keepalived_vrrp[5539]:VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 10.10.195.212

(BACKUP:10.10.195.190)

Sep 29 15:46:25 server1 Keepalived[18218]:Starting Keepalived v1.2.19 (09/25,2015)

Sep 29 15:46:25 server1Keepalived_healthcheckers[18220]: Netlink reflector reports IP 10.10.195.190added

Sep 29 15:46:25 server1Keepalived_healthcheckers[18220]: Netlink reflector reports IP 10.10.195.190added

Sep 29 15:46:25 server1Keepalived_healthcheckers[18220]: Registering Kernel netlink reflector

Sep 29 15:46:25 server1Keepalived_healthcheckers[18220]: Registering Kernel netlink command channel

Sep 29 15:46:25 server1 Keepalived_healthcheckers[18220]:Opening file '/etc/keepalived/keepalived.conf'.

Sep 29 15:46:25 server1Keepalived_healthcheckers[18220]: Configuration is using : 6682 Bytes

Sep 29 15:46:25 server1 Keepalived[18219]:Starting Healthcheck child process, pid=18220

Sep 29 15:46:25 server1 Keepalived[18219]:Starting VRRP child process, pid=18221

Sep 29 15:46:25 server1Keepalived_vrrp[18221]: Netlink reflector reports IP 10.10.195.190 added

Sep 29 15:46:25 server1Keepalived_vrrp[18221]: Netlink reflector reports IP 10.10.195.190 added

Sep 29 15:46:25 server1Keepalived_healthcheckers[18220]: Using LinkWatch kernel netlink reflector...

Sep 29 15:46:25 server1Keepalived_vrrp[18221]: Registering Kernel netlink reflector

Sep 29 15:46:25 server1Keepalived_vrrp[18221]: Registering Kernel netlink command channel

Sep 29 15:46:25 server1Keepalived_vrrp[18221]: Registering gratuitous ARP shared channel

Sep 29 15:46:25 server1Keepalived_vrrp[18221]: Opening file '/etc/keepalived/keepalived.conf'.

Sep 29 15:46:25 server1 Keepalived_vrrp[18221]:Configuration is using : 36651 Bytes

Sep 29 15:46:25 server1Keepalived_vrrp[18221]: Using LinkWatch kernel netlink reflector...

Sep 29 15:46:25 server1Keepalived_vrrp[18221]: VRRP_Instance(VI_1) Entering BACKUP STATE

Sep 29 15:46:25 server1 Keepalived_vrrp[18221]:VRRP sockpool: [ifindex(2), proto(112), unicast(0), fd(10,11)]

3.2 主备切换

l 当在主机（MASTER：10.10.195.53）中输入 sudoservice keepalived stop，此时就会进行主备切换，主机切换成备机。

主机（MASTER：10.10.195.53）输出如下

Oct 14 13:25:09 shr Keepalived_vrrp[26683]:VRRP_Instance(VI_1) sending 0 priority

Oct 14 13:25:09 shr Keepalived_vrrp[26683]:VRRP_Instance(VI_1) removing protocol VIPs.

Oct 14 13:25:09 shrKeepalived_healthcheckers[26682]: Netlink reflector reports IP 10.10.195.212removed

Oct 14 13:25:09 shr Keepalived[26681]:Stopping Keepalived v1.2.19 (09/21,2015)

备机(BACKUP:10.10.195.190)输出如下

Oct 14 13:19:58 server1Keepalived_vrrp[30890]: VRRP_Instance(VI_1) Transition to MASTER STATE

Oct 14 13:19:59 server1Keepalived_vrrp[30890]: VRRP_Instance(VI_1) Entering MASTER STATE

Oct 14 13:19:59 server1Keepalived_vrrp[30890]: VRRP_Instance(VI_1) setting protocol VIPs.

Oct 14 13:19:59 server1Keepalived_vrrp[30890]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for10.10.195.212

Oct 14 13:19:59 server1 Keepalived_healthcheckers[30889]:Netlink reflector reports IP 10.10.195.212 added

Oct 14 13:19:59 server1Keepalived_vrrp[30890]: Netlink reflector reports IP 10.10.195.212 added

Oct 14 13:20:04 server1Keepalived_vrrp[30890]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for10.10.195.212

l 当在主机（MASTER：10.10.195.53）中输入sudoservice keepalived start,此时就会切换成主机。备机(BACKUP:10.10.195.190)输出如下信息：

Oct 14 13:25:11 server1Keepalived_vrrp[30890]: VRRP_Instance(VI_1) Received higher prio advert

Oct 14 13:25:11 server1Keepalived_vrrp[30890]: VRRP_Instance(VI_1) Entering BACKUP STATE

Oct 14 13:25:11 server1Keepalived_vrrp[30890]: VRRP_Instance(VI_1) removing protocol VIPs.

Oct 14 13:25:11 server1Keepalived_healthcheckers[30889]: Netlink reflector reports IP 10.10.195.212removed

Oct 14 13:25:11 server1Keepalived_vrrp[30890]: Netlink reflector reports IP 10.10.195.212 removed

4. 查看虚拟ip

可以通过ip add show命令查看添加的虚拟ip：

[shr@shr bin]$ip add show

1: lo: mtu16436 qdisc noqueue

link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

inet 127.0.0.1/8 scope host lo

2: eth0: mtu 1500 qdisc pfifo_fast qlen 1000

link/ether 00:0c:29:6b:f2:a8 brd ff:ff:ff:ff:ff:ff

inet 10.10.195.53/24 brd 10.10.195.255 scope global eth0

inet 10.10.195.212/32scope global eth0

5. 常见错误

5. 1常见错误一：

/var/log/messages has thousands of errorslike this:

Jun 28 09:18:32 rust Keepalived_vrrp:receive an invalid ip number count

associated with VRID!

Jun 28 09:18:32 rust Keepalived_vrrp: bogusVRRP packet received on eth0 !!!

Jun 28 09:18:32 rust Keepalived_vrrp:VRRP_Instance(VI_1) Dropping received

VRRP packet...

The backup director starts up, but doesn'tlisten on the virtual addresses

at all. Its /var/log/messages has thousands of errors like this:

Jun 28 06:25:05 stye Keepalived_vrrp:receive an invalid ip number count

associated with VRID!

Jun 28 06:25:05 stye Keepalived_vrrp: bogusVRRP packet received on eth0 !!!

Jun 28 06:25:05 stye Keepalived_vrrp:VRRP_Instance(VI_1) ignoring received

advertisment...

解决方法：

改变配置文件/etc/keepalived/keepalived.conf中virtual_router_id为另一个值即可。

（changed the vrid to another number and it worked fine）.

5.2 常见错误二：

主机执行到VRRP_Instance(VI_1) Entering BACKUP STATE之后没有执行VRRP_Instance(VI_1)setting protocol VIPs。

解决方法：

可能是配置文件keepalived.conf中{左边没有空格。

附

linux添加tomcat服务

在/etc/init.d中输入 sudo vim tomcat

脚本具体内容如下：

#!/bin/bash

#chkconfig: 2345 10 90

#description: Starts and Stops the tomcatdaemon

#edited by ZZH: 2015-10-14

CATALINA_HOME=/users/shr/apache-tomcat-7.0.64

JAVA_HOME=/users/shr/util/JavaDir/jdk

export CATALINA_HOME

export JAVA_HOME

start_tomcat=$CATALINA_HOME/bin/startup.sh

stop_tomcat=$CATALINA_HOME/bin/shutdown.sh

if [ ! -f $CATALINA_HOME/bin/catalina.sh ]

then

echo"===Tomcat is not available.==="

exit

fi

start()

{

echo-n "===Starting tomcat===:"

${start_tomcat}

echo"===tomcat start ok.==="

}

stop()

{

echo-n "===Shutting down tomcat===:"

${stop_tomcat}

echo"===tomcat stop ok.==="

}

status()

{

ps ax --width=1000 | grep"org.apache.catalina.startup.Bootstrap start" | grep -v"grep" | awk '{printf $1 " "}' | wc | awk '{print $2}'> tomcat_process_count.txt

readline < tomcat_process_count.txt  

rmtomcat_process_count.txt

if[ $line -gt 0 ]

then

echo-n "tomcat ( pid = "

ps ax --width=1000 | grep"org.apache.catalina.startup.Bootstrap start" | grep -v"grep" | awk '{printf $1 " "}' | awk '{print $1}'> tomcat_process_pid.txt

readpid < tomcat_process_pid.txt  

rmtomcat_process_pid.txt

echo-n $pid

echo-n ") is running..."

echo

else

echo"tomcat is stopped"

fi

}

case "$1" in

start)

start

;;

stop)

stop

;;

restart)

stop

sleep1

start

;;

status)

status

;;

*)

echo"Usage:$0 {start|stop|restart}"

exit1

esac

exit 0

# shell end.

在终端输入:

sudo chmod 755 tomcat

sudo chkconfig --add tomcat

tomcat 启动 service tomcatstart

tomcat 关闭 service tomcatstop

tomcat 重启 service tomcatrestart

tomcat状态查看 service tomcatstatus