1、启动 elasticsearch 如出现异常 can not run elasticsearch as root
解决方法：创建ES 账户，修改文件夹 文件 所属用户 组
2、启动异常：ERROR: bootstrap checks failed
system call filters failed to install; check the logs and fix your configuration or disable system call filters at your own risk
问题原因：因为Centos6不支持SecComp，而ES5.2.1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。详见 ：https://github.com/elastic/elasticsearch/issues/22899
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
3、启动后，如果只有本地可以访问，尝试修改配置文件 elasticsearch.yml
中network.host(注意配置文件格式不是以 # 开头的要空一格， ： 后要空一格)
为 network.host: 0.0.0.0
默认端口是 9200
注意：关闭防火墙 或者开放9200端口
4、ERROR: bootstrap checks failed
max file descriptors [4096] for elasticsearch process likely too low, increase to at least [65536]
max number of threads [1024] for user [lishang] likely too low, increase to at least [2048]
解决方法：切换到root用户，编辑limits.conf 添加类似如下内容
vi /etc/security/limits.conf
添加如下内容:
* soft nofile 65536
* hard nofile 131072
* soft nproc 2048
* hard nproc 4096
5、max number of threads [1024] for user [lish] likely too low, increase to at least [2048]
解决：切换到root用户，进入limits.d目录下修改配置文件。
vi /etc/security/limits.d/90-nproc.conf
修改如下内容：
* soft nproc 1024
#修改为
* soft nproc 2048
6、max virtual memory areas vm.max_map_count [65530] likely too low, increase to at least [262144]
解决：切换到root用户修改配置sysctl.conf
vi /etc/sysctl.conf
添加下面配置：
vm.max_map_count=655360
并执行命令：
sysctl -p
然后，重新启动elasticsearch，即可启动成功。
内存不足:
Java HotSpot(TM) Server VM warning: INFO: os::commit_memory(0xcc000000, 469762048, 0) failed; error='Cannot allocate memory' (errno=12)
#
# There is insufficient memory for the Java Runtime Environment to continue.
# Native memory allocation (mmap) failed to map 469762048 bytes for committing reserved memory.
# An error report file with more information is saved as:
# /usr/local/elasticsearch/bin/hs_err_pid7598.log
解决：修改足够的内存
# vi elasticsearch目录/config/jvm.options
将-Xms2g
-Xmx2g
改为:
-Xms512M
-Xmx512M
elasearch不能用root用户启动 需要配置独立用户