启动异常：ERROR: bootstrap checks failed
system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
问题原因：因为Centos6不支持SecComp，而ES默认bootstrap.system_call_filter为true进行检测，所以导致检测失败，失败后直接导致ES不能启动。详见 ：https://github.com/elastic/elasticsearch/issues/22899
解决方法：在elasticsearch.yml中配置bootstrap.system_call_filter为false，注意要在Memory下面:
bootstrap.memory_lock: false
bootstrap.system_call_filter: false
ERROR: [2] bootstrap checks failed
[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]
[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
启动报这个错误；
问题1 [1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]
修改/etc/security/limits.conf文件，添加或修改如下行： （请切换到root用户 然后强制修改文件）
* hard nofile 65536
* soft nofile 65536
问题2 [2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
$ sudo sysctl -w vm.max_map_count=2621441
或者修改 /etc/sysctl.conf 文件，添加 “vm.max_map_count”设置 永久改变(sudo sysctl -p /etc/sysctl.conf生效)。
设置后，重启服务器，可以使用