es 问题

1，elasticsearch can not run as root

groupadd es
useradd es -g es
runuser es
./elasticserch

2, 修改配置后运行，es file descriptors [4096]等等，需要修改系统限制

ERROR: bootstrap checks failed
max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]
max number of threads [1024] for user [es] is too low, increase to at least [2048]
max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

ulimit -a
ulimit -n 32000
vi /etc/security/limits.conf
* soft nofile 65536
* hard nofile 131072
* soft nproc 2048
* hard nproc 4096

退出runuser，重新进入runuser es

3、system call filters failed to install;

elasticsearch.yml
memory下
bootstrap.memory_lock: false
bootstrap.system_call_filter: false

4、max number of threads [1024]

vi /etc/security/limits.d/90-nproc.conf
* soft nproc 2048

5、max virtual memory areas vm.max_map_count [65530] likely too low

vi /etc/sysctl.conf
vm.max_map_count=655360
sysctl -p

6、每个es实例不要超过32G，Don’t Cross 32 GB!