es启动默认不能使用root用户，所以需要新创建一个用户来启动。
启动时可能出现的问题:
[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]
[2]: max number of threads [1024] for user [esuser1] is too low, increase to at least [4096]
[3]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[4]: system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
1.修改最大文件描述符数量为65536:
编辑文件:/etc/security/limits.conf
添加：
* soft nofile 65536
* hard nofile 65536
2.修改用户最大线程数为4096
编辑文件:/etc/security/limits.d/90-nproc.conf
* soft nproc 1026
修改为:
* soft nproc 4096
3.修改最大虚拟内存区域为262144
修改文件:/etc/sysctl.conf
添加
vm.max_map_count = 262144
4.在elasticsearch.yml文件中的memory栏添加
bootstrap.memory_lock: false
bootstrap.system_call_filter: false
)
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