daqungege

**Describe the bug** 压测一段时间后，polardbcpu一直飙升 **To Reproduce** Steps to reproduce the behavior: 1. 系统一直请求 2. 过2个小时，polarcpu飙升， 3. 重启polardb恢复正常 **Expected behavior** A clear and concise description of what you expected to happen....