我们在SpringBoot中用Jedis来访问Redis，其中Redis是采用集群（单机没有本篇文章的问题）的方式，在启用Redis的时候碰到如上问题。
错误的核心信息如下：
Error creating bean with name 'enableRedisKeyspaceNotificationsInitializer' defined in class path resource
完整信息如下：
// 下午4:: . ____ _ __ _ _
// 下午4:: /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
// 下午4::( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
// 下午4:: \\/ ___)| |_)| | | | | || (_| | ) ) ) )
// 下午4:: ' |____| .__|_| |_|_| |_\__, | / / / /
// 下午4:: =========|_|==============|___/=/_/_/_/
// 下午4:: :: Spring Boot :: (v1.5.1.RELEASE)
// 下午4::
// 下午4::40Nov , :: PM com.navercorp.pinpoint.bootstrap.config.DefaultProfilerConfig readBoolean
// 下午4::40INFO: profiler.jdk.http.param=true
// 下午4::40Nov , :: PM com.navercorp.pinpoint.bootstrap.config.DefaultProfilerConfig readBoolean
// 下午4::40INFO: profiler.jdk.http.param=true
// 下午4::40Nov , :: PM com.navercorp.pinpoint.bootstrap.config.DefaultProfilerConfig readBoolean
// 下午4::40INFO: profiler.jdk.http.param=true
// 下午4::52org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'enableRedisKeyspaceNotificationsInitializer' defined in class path resource [org/springframework/session/data/redis/config/annotation/web/http/RedisHttpSessionConfiguration.class]: Invocation of init method failed; nested exception is org.springframework.data.redis.RedisConnectionFailureException: Cannot get Jedis connection; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
// 下午4:: at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:)
// 下午4:: at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:)
// 下午4:: at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:)
// 下午4:: at org.springframework.beans.factory.support.AbstractBeanFactory$.getObject(AbstractBeanFactory.java:)
// 下午4:: at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:)
// 下午4:: at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:)
// 下午4:: at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:)
// 下午4:: at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:)
// 下午4:: at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:)
// 下午4:: at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:)
// 下午4:: at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:)
// 下午4:: at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:)
// 下午4:: at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:)
// 下午4:: at org.springframework.boot.SpringApplication.run(SpringApplication.java:)
// 下午4:: at org.springframework.boot.SpringApplication.run(SpringApplication.java:)
// 下午4:: at org.springframework.boot.SpringApplication.run(SpringApplication.java:)
// 下午4:: at com.zte.Application.main(Application.java:)
// 下午4:: at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
// 下午4:: at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:)
// 下午4:: at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:)
// 下午4:: at java.lang.reflect.Method.invoke(Method.java:)
// 下午4:: at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:)
// 下午4:: at org.springframework.boot.loader.Launcher.launch(Launcher.java:)
// 下午4:: at org.springframework.boot.loader.Launcher.launch(Launcher.java:)
// 下午4:: at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:)
// 下午4::52Caused by: org.springframework.data.redis.RedisConnectionFailureException: Cannot get Jedis connection; nested exception is redis.clients.jedis.exceptions.JedisConnectionException: Could not get a resource from the pool
// 下午4:: at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.fetchJedisConnector(JedisConnectionFactory.java:)
// 下午4:: at org.springframework.data.redis.connection.jedis.JedisConnectionFactory.getConnection(JedisConnectionFactory.java:)
// 下午4:: at org.springframework.session.data.redis.config.annotation.web.http.RedisHttpSessionConfiguration$EnableRedisKeyspaceNotifica
经查找，在Java代码中，我们使用了注解：@EnableRedisHttpSession，这个注解是用来开启Redis来集式式管理Session。
而在使用这种方式的时候，是需要Redis开启Keyspace Notifications功能的，默认是关闭的。
这个功能有一个参数来控制它，notify-keyspace-events，值为Egx。
可以通过在Redis.Config中配置。
也可以通过命令行来配置，如下所示：
redis-cli config set notify-keyspace-events Egx然后重启Redis生效。
参考文档：
https://docs.spring.io/spring-session/docs/current/reference/html5/#api-redisoperationssessionrepository-sessiondestroyedevent
http://blog.csdn.net/xiaoyu411502/article/details/51248980