Several problems encountered and solutions Elasticsearch

Es startup problems encountered:
 

ERROR: [5] bootstrap checks failed
[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]
[2]: memory locking requested for elasticsearch process but memory is not locked
[3]: max number of threads [1024] for user [wangxiang] is too low, increase to at least [4096]
[4]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[5]: system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk

Solution:
1. Modify vi /etc/security/limits.conf file, increase the allocation

*               soft    nofile          65536
*               hard    nofile          65536

2. Switch to the root user, edit vi /etc/security/limits.conf configuration file, add the following: 

* soft memlock unlimited 

* hard memlock unlimited 

Note: Linux * on behalf of all user names

3. The maximum number of threads is too low. Modify the configuration file vi /etc/security/limits.d/90-nproc.conf

*               soft    nproc           4096
*               hard    nproc           4096

4. Modify /etc/sysctl.conf file, increase the allocation

vm.max_map_count=262144

Run sysctl -p take effect

5. Add items arranged in elasticsearch.yml

bootstrap.memory_lock: false
bootstrap.system_call_filter: false