断线重连
https://stackoverflow.com/questions/37029341/how-to-reconnect-socket-using-threads
redis reconnect
https://stackoverflow.com/questions/10879426/how-to-reconnect-redis-connection
https://github.com/NodeRedis/node-redis/issues/1007
https://developer.ibm.com/depmodels/cloud/articles/error-detection-and-handling-with-redis/
一种解决方案是使用一个thread,每隔一段时间就取检查,另外一种实现方式是当出现错误的时候,才去重连。