don't run elasticsearch as root：

解决办法：Elasticsearch是不允许使用root用户来运行的，所以需要把ElasticSearch目录所有者修改为其他用户，并切换到该用户去执行。

Likely root cause: java.nio.file.AccessDeniedException: /home/esuser/elasticsearch-

7.3.0/config/elasticsearch.keystore

原因：elasticsearch.keystore是root用户导致的

解决方法：elasticsearch.keystore赋予esuser用户权限

Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x0000000085330000,

2060255232, 0) failed; error='Cannot allocate memory' (errno=12)

原因：由于elasticsearch默认分配jvm空间大小为1g，修改jvm空间分配

解决方法：vi config/jvm.options

将文件中

-Xms2g

-Xmx2g

修改为

-Xms512m

-Xmx512m

unable to install syscall filter:

java.lang.UnsupportedOperationException: seccomp unavailable: CONFIG_SECCOMP not # compiled into kernel, CONFIG_SECCOMP and CONFIG_SECCOMP_FILTER are needed

原因：因为Centos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

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

max file descriptors [4096] for elasticsearch process likely too low, increase to at least [65536]

原因：无法创建本地文件问题,用户最大可创建文件数太小

解决方法：切换到root用户，编辑limits.conf配置文件， 添加类似如下内容：

vi /etc/security/limits.conf

添加如下内容:

* soft nofile 65536

* hard nofile 65536

* soft nproc 2048

* hard nproc 4096

main ERROR RollingFileManager (/usr/local/software/elasticsearch-5.5.2/logs/elasticsearch.log)

java.io.FileNotFoundException: /usr/local/software/elasticsearch-5.5.2/logs/elasticsearch.log

(Permission denied) java.io.FileNotFoundException: /usr/local/software/elasticsearch-5.5.2/logs/elasticsearch.log (Permission denied)

原因：这是权限不足的问题。

解决方法：切换到root 用户 切换到elasticsearch安装目录 给esuer用户授权即可

elasticSearch本地可以访问网页无法访问的解决方法

解决方法：service firewalld stop

如果绑定本地ip失败，那么在elasticsearch.yml里面加上

bootstrap.memory_lock: false

bootstrap.system_call_filter: false

Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000c5330000, 986513408, 0) failed; error='Cannot allocate memory' (errno=12)：

解决办法：内存不足，升级内存

Exception in thread "main" java.nio.file.AccessDeniedException

解决办法：运行Elasticsearch程序的用户权限不够，把Elasticsearch目录权限修改下即可

max virtual memory areas vm.max_map_count [65530] is too low

解决办法：修改/etc/sysctl.conf，增加一行vm.max_map_count= 262144。然后执行sysctl -p使其生效

max number of threads [3812] for user [elkuser] is too low, increase to at least [4096]

解决办法：修改/etc/security/limits.d/20-nproc.conf，做以下配置

* soft nproc 4096

* hard nproc 4096