elasticsearch7.4.0啓動報錯：
ERROR: [3] bootstrap checks failed
[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65535]
[2]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]
[3]: the default discovery settings are unsuitable for production use; at least one of [discovery.seed_hosts, discovery.seed_providers, cluster.initial_master_nodes] must be configured
解決操作
以下操作需切換到root用戶下
$ sudo -s
問題[1]
查看軟硬限制命令
# ulimit -Su
# ulimit -Hu
在文件 /etc/security/limits.conf 末尾添加以下內容（* 表示所有用戶）
* soft nofile 65536
* hard nofile 131072
如果還報錯max number of threads [3818] for user [es] is too low, increase to at least [4096]
則需要在 /etc/security/limits.conf 末尾 追加
* soft nproc 2048
* hard nproc 4096
以上配置需要用戶重新登陸後生效
問題[2]
臨時修改解決辦法（重啓系統失效）：
# sysctl -w vm.max_map_count=262144
查看結果：
# sysctl -a|grep vm.max_map_count
顯示：vm.max_map_count = 262144
永久修改解決辦法：
在 /etc/sysctl.conf文件最後添加一行
vm.max_map_count=262144
生效查看：
# sysctl -p
問題[3]
修改 config/elasticsearch.yml 保留一個節點
cluster.initial_master_nodes: ["node-1"]
其它問題
system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
在 config/elasticsearch.yml中修改或添加配置項：
bootstrap.memory_lock: false
bootstrap.system_call_filter: false