明天在测试环境冒烟，发现redis报错，JedisDataException: OOM command not allowed when used memory > 'maxmemory'!
狐疑是写入redis key过大导致，于是排查redis内存应用状况，应用INFO命令，后果如下，
能够看到最大内存为256M，理论应用曾经262M，故报错，因为测试服务器没有redis客户端，只能通过DEBUG OBJECT KEY进行排查，发现是在进行每日下单用户数量统计时，因为用户数量过多，存储的userId导致key过大，通过理论业务思考redis大小配置以及调整代码解决
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