elasticsearch踩过的坑解决办法

1、Java HotSpot(TM) 64-Bit Server VM warning: INFO: os::commit_memory(0x0000000085330000, 2060255232, 0) failed; error=’Cannot allocate memory’ (errno=12)
由于elasticsearch5.0默认分配jvm空间大小为2g，修改jvm空间分配

vim config/jvm.options
-Xms2g
-Xmx2g
修改为
-Xms512m
-Xmx512m

2、max number of threads [1024] for user [elasticsearch] is too low, increase to at least [2048] 修改 /etc/security/limits.d/90-nproc.conf

soft nproc 1024

soft nproc 2048

3、max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

修改/etc/sysctl.conf配置文件，

cat /etc/sysctl.conf | grep vm.max_map_count
vm.max_map_count=262144

如果不存在则添加

echo "vm.max_map_count=262144" >>/etc/sysctl.conf

4、max file descriptors [65535] for elasticsearch process likely too low, increase to at least [65536]

ulimit -n 65536

5.外网访问

vi conf/elasticsearch.yml

修改network.host: 0.0.0.0
再次启动linux可能出现如下类似错误

bootstrap checks failed
max file descriptors [65535] for elasticsearch process is too low, increase to at least [65536]

解决方案
1、vi /etc/sysctl.conf
设置fs.file-max=655350
保存之后sysctl -p使设置生效
2、vi /etc/security/limits.conf 新增

soft nofile 655350

hard nofile 655350

3、重新使用SSH登录，再次启动elasticsearch即可。
外网访问：serverip:9200/