ElasticSearch 启动常见错误

1、版本一致性

Elasticsearch 客户端版本和服务器版本需一致

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

• 每个进程最大同时打开文件数太小，可通过下面2个命令查看当前数量

  ulimit -Hn
  ulimit -Sn
  

• 修改/etc/security/limits.conf文件，增加配置，用户退出后重新登录生效

  *               soft    nofile          65536
  *               hard    nofile          65536
  

3、max number of threads [3818] for user [es] is too low, increase to at least [4096]

• 问题同上，最大线程个数太低。修改配置文件/etc/security/limits.conf（和问题1是一个文件），增加配置

  *               soft    nproc           4096
  *               hard    nproc           4096
  

• 可通过命令查看

  ulimit -Hu
  ulimit -Su
  

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

• 虚拟内存太小，修改 /etc/sysctl.conf文件，

  vim /etc/systcl.conf
  sysctl -p
  

• 增加下列配置

  vm.max_map_count=262144
  

5、Exception in thread "main" java.nio.file.AccessDeniedException: /usr/local/elasticsearch/elasticsearch-6.2.2-1/config/jvm.options

• elasticsearch用户没有该文件夹的权限，执行命令

  chown -R es:es /usr/local/elasticsearch/