[问题澄清]
TiDB集群安装过程中报错：
Ansible FAILED! => playbook: bootstrap.yml; TASK: check_system_static : Preflight check - Check if the operating system supports EPOLLEXCLUSIVE; message: {“changed”: true, “cmd”: “/home/tidb/deploy/epollexclusive”, “delta”: “0:00:00.007020”, “end”: “2019-10-16 10:29:15.858494”, “msg”: “non-zero return code”, “rc”: 1, “start”: “2019-10-16 10:29:15.851474”, “stderr”: “”, “stderr_lines”: [], “stdout”: “epoll_ctl with EPOLLEXCLUSIVE | EPOLLONESHOT succeeded. This is evidence of no EPOLLEXCLUSIVE support. Not using epollex polling engine.False: epollexclusive is not available”, “stdout_lines”: [“epoll_ctl with EPOLLEXCLUSIVE | EPOLLONESHOT succeeded. This is evidence of no EPOLLEXCLUSIVE support. Not using epollex polling engine.False: epollexclusive is not available”]}
[原因分析]
操作系统版本过低，为支持EPOLLEXCLUSIVE
[解决方案]
升级操作系统版本，参考安装配置建议
https://pingcap.com/docs-cn/stable/how-to/deploy/hardware-recommendations/
[参考案例]
部署TIDB EPOLLEXCLUSIVE 报错问题
部署TIDB EPOLLEXCLUSIVE 报错问题
[引申学习点]
一个epoll惊群导致的性能问题
epoll: add EPOLLEXCLUSIVE flag
https://github.com/torvalds/linux/commit/df0108c5da561c66c333bb46bfe3c1fc65905898