克服cas单点故障，将cas认证请求分发到多台cas服务器上，降低负载。

采用统一的ticket存取策略，所有ticket的操作都从**缓存redis中存取。
采用session共享，session的存取都从**缓存redis中存取。

这里只讲解如何实现cas ticket的共享，关于session的共享请移步：

<bean id="ticketRegistry" class="org.jasig.cas.ticket.registry.DefaultTicketRegistry" />

<bean id="ticketRegistry" class="ren.boot.cas.ticket.registry.RedisTicketRegistry">
    <constructor-arg index="0" ref="redisTemplate" />

    <!-- TGT timeout in seconds -->
    <constructor-arg index="1" value="1800" />

    <!-- ST timeout in seconds -->
    <constructor-arg index="2" value="300" />
</bean>
<!-- redis连接池 -->
<bean id="jedisConnFactory"
      class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
      p:hostName="192.168.1.89"
      p:database="0"
      p:usePool="true"/>
<bean id="redisTemplate" class="org.jasig.cas.ticket.registry.TicketRedisTemplate"
      p:connectionFactory-ref="jedisConnFactory"/>

<!-- 票据保存方式及有效期设置 -->
<alias name="redisTicketRegistry" alias="ticketRegistry" />
<bean id="redisTicketRegistry" class="ren.boot.cas.ticket.registry.RedisTicketRegistry"
    p:client-ref="ticketRedisTemplate"
    p:tgtTimeout="28800"
    p:stTimeout="10"/>
<!-- redis连接池 -->
<bean id="jedisConnFactory"
      class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
      p:hostName="localhost"
      p:database="0"
      p:usePool="true"/>
<bean id="ticketRedisTemplate" class="ren.boot.cas.ticket.registry.TicketRedisTemplate"
      p:connectionFactory-ref="jedisConnFactory"/>