一个大型站点都会涉及到动态应用，动态应用都需要做会话保持，常见的会话保持方式就三种，一是session stick，二是session replication，三是session share，对于小型规模的tomcat集群，大多者会采用session replication方式，但阅读官方文档也好，查询大牛博客也罢，发现均有不准确之处，所以亲测成功实现之后得出如下文档，还望高人指点。
实验环境：
操作系统：CentOS 7.2
tomcat版本：tomcat-7.0.54（yum安装方式）
httpd版本：httpd-2.4.6（yum安装方式）
nginx版本：nginx-1.10.2（yum安装方式）
iptables状态：disable
SELinux状态：disable
TomcatA配置过程
[root@TomcatA ~]# ifconfig
eno16777736:flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.0.20 netmask255.255.255.0 broadcast 192.168.0.255
inet6 fe80::20c:29ff:fefe:64f3 prefixlen 64 scopeid0x20<link>
ether 00:0c:29:fe:64:f3 txqueuelen 1000 (Ethernet)
RX packets 1147 bytes 141324(138.0 KiB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 659 bytes 102242 (99.8KiB)
TX errors 0 dropped 0 overruns0 carrier 0 collisions 0
lo:flags=73<UP,LOOPBACK,RUNNING> mtu65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 0 (Local Loopback)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns0 carrier 0 collisions 0
[root@TomcatA ~]# cat/etc/yum.repos.d/hehe.repo
[cdrom-repo]
name=cdrom-repo
baseurl=file:///cdrom
gpgcheck=0
[aliyun-epel]
name=aliyun-epel
baseurl=http://mirrors.aliyun.com/epel/7/x86_64/
gpgcheck=0
[root@TomcatA ~]#
[root@TomcatA ~]# yum install -y tomcat
[root@TomcatA ~]# mkdir -pv/usr/share/tomcat/webapps/ROOT/WEB-INF
mkdir: created directory‘/usr/share/tomcat/webapps/ROOT’
mkdir: created directory‘/usr/share/tomcat/webapps/ROOT/WEB-INF’
[root@TomcatA ~]# vim/usr/share/tomcat/webapps/ROOT/index.jsp
[root@TomcatA ~]# cat/usr/share/tomcat/webapps/ROOT/index.jsp
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
<%@ page language="Java" %> <html> <head><title>TomcatA</title></head> <body> <h1><fontcolor="red">TomcatA</font></h1> <table border="1"> <tr> <td>SessionID</td> <%session.setAttribute("test.com","test.com"); %> <td><%=session.getId() %></td> </tr> <tr> <td>Createdon</td> <td><%=session.getCreationTime() %></td> </tr> </table> </body> </html>
[root@TomcatA ~]# scp/usr/share/tomcat/webapps/ROOT/index.jsp 192.168.0.21:/usr/share/tomcat/webapps/ROOT/
The authenticity of host '192.168.0.21(192.168.0.21)' can't be established.
ECDSA key fingerprint isfc:7f:15:2b:2d:69:c9:c1:b0:79:7c:ce:ab:c0:0c:36.
Are you sure you want to continueconnecting (yes/no)? yes
Warning: Permanently added '192.168.0.21'(ECDSA) to the list of known hosts.
root@192.168.0.21's password: