业务场景

单点登录服务器如果压力过大的情况，那么可以使用集群分担压力，但是cas 默认不支持session同步。

所以可以需要做session同步，可以使用j2cache 实现session同步。

实现方法

1.准备jar包

将这些包copy 到cas的 WEB-INF/lib目录下

2.编辑CAS web.xml 文件

在web.xml 的

<filter-mapping>
        <filter-name>encoding-filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

后面添加

 <filter>
    <filter-name>j2cache-session-filter</filter-name>
    <filter-class>net.oschina.j2cache.session.J2CacheSessionFilter</filter-class>
    <init-param><!-- 内存中存放会话数 -->
        <param-name>session.maxSizeInMemory</param-name>
        <param-value>2000</param-value>
    </init-param>
    <init-param><!-- 会话有效期，单位：秒钟 -->
        <param-name>session.maxAge</param-name>
        <param-value>1800</param-value>
    </init-param>
    <!-- cookie configuration -->
    <init-param>
        <param-name>cookie.name</param-name>
        <param-value>J2CACHE_SESSION_ID</param-value>
    </init-param>
    <init-param>
        <param-name>cookie.path</param-name>
        <param-value>/</param-value>
    </init-param>
    <init-param>
        <param-name>cookie.domain</param-name>
        <param-value></param-value>
    </init-param>
 
   
            <init-param>
                <param-name>redis.mode</param-name>
                <param-value>single</param-value>
            </init-param>
            <init-param>
                <param-name>redis.hosts</param-name>
                <param-value>192.168.31.100:6379</param-value>
            </init-param>
            <init-param>
                <param-name>redis.channel</param-name>
                <param-value>j2cache</param-value>
            </init-param>
            <init-param>
                <param-name>redis.cluster_name</param-name>
                <param-value>j2cache</param-value>
            </init-param>
            <init-param>
                <param-name>redis.timeout</param-name>
                <param-value>2000</param-value>
            </init-param>
            <init-param>
                <param-name>redis.password</param-name>
                <param-value></param-value>
            </init-param>
            <init-param>
                <param-name>redis.database</param-name>
                <param-value>0</param-value>
            </init-param>
            <init-param>
                <param-name>redis.maxTotal</param-name>
                <param-value>100</param-value>
            </init-param>
            <init-param>
                <param-name>redis.maxIdle</param-name>
                <param-value>10</param-value>
            </init-param>
            <init-param>
                <param-name>redis.minIdle</param-name>
                <param-value>10</param-value>
            </init-param>
        </filter>

        <filter-mapping>
            <filter-name>j2cache-session-filter</filter-name>
            <url-pattern>/*</url-pattern>
        </filter-mapping>

redis 可以做相应配置。

3.NGINX配置

upstream linuxidc {
            server 192.168.31.77:8082;
            server 192.168.31.77:8081;
        
        }

添加cas配置

location /cas {
                        proxy_pass http://linuxidc/cas;
                        proxy_set_header Host $host:$server_port;
            proxy_set_header X-Real-Ip $remote_addr;
            proxy_set_header X-Forwarded-For $remote_addr;
        }

这样就实现了cas session同步。