安装配置Elasticsearch5.4.1的时候遇到的一些问题，通过查找资料解决。整理记录一下，便于以后遇到同样的问题能够快速解决。

Elasticsearch安装好后，默认只允许通过127.0.0.1访问，如果我们希望在另外一台机器上访问Elasticsearch的话，需要修改主机配置：

#network.host: 192.168.0.1 networ.host: 192.168.5.82 <--修改为本机iP，或者0.0.0.0

保存退出后，重新启动Elasticsearch的话会报错，无法启动。报错如下：

[WARN ][o.e.b.JNANatives         ] unable to install syscall filter: java.lang.UnsupportedOperationException: seccomp unavailable: requires kernel 3.5+ with CONFIG_SECCOMP and CONFIG_SECCOMP_FILTER compiled inERROR: [4] bootstrap checks failed[1]: max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536][2]: max number of threads [1024] for user [elsearch] is too low, increase to at least [2048][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　　

WARN:只是一个警告，使用新版本的linux就没事了。

错误一：max file descriptors [4096] for elasticsearch process is too low, increase to at least [65536]

修改/etc/security/limits.conf配置文件，添加如下内容：

# vim /etc/security/limits.conf * soft nofile 65536* hard nofile 131072* soft nproc 2048* hard nproc 4096

错误二：max number of threads [1024] for user [elsearch] is too low, increase to at least [2048]

修改/etc/security/limits.d/90-nproc.conf配置文件，修改内容如下： 

# vim /etc/security/limits.d/90-nproc.conf* soft nproc 1024#修改为* soft nproc 2048

错误三：max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

修改配置文件/etc/sysctl.conf，修改内容如下：

# vim /etc/sysctl.conf添加下面配置：vm.max_map_count = 655360

错误四：system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk原因：

这是在因为操作系统不支持SecComp，而ES5.4.1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：

在elasticsearch.yml中配置bootstrap.system_call_filter为false，注意要在Memory下面:

bootstrap.memory_lock: falsebootstrap.system_call_filter: false

修改好后重启ES，能够正常启动。