清楚redis缓存的时候，出现以下问题：
(error) MISCONF Redis is configured to save RDB snapshots, but is currently not able to persist on disk. Commands that may modify the data set are disabled. Please check Redis logs for details about the error.
解决方法，输入以下命令
127.0.0.1:6379> config set stop-writes-on-bgsave-error no