ELK学习003：Elasticsearch启动常见问题

一、Caused by: java.lang.RuntimeException: can not run elasticsearch as root

这个错误，是因为使用root用户启动elasticsearch，elasticsearch是不允许使用root用户启动的，所以我们需要添加用户。

[root@localhost ~]# adduser elsearch
[root@localhost ~]# passwd elsearch
[root@localhost ~]# chown -R elsearch:elsearch elasticsearch-7.6.0
[root@localhost ~]# chmod 770 elasticsearch-7.6.0/      # 这一步之后，切换到elsearch用户，再执行下面两条命令。
[root@localhost ~]# cd elasticsearch-7.6.0/
[root@localhost ~]# bin/elasticsearch

二、OpenJDK 64-Bit Server VM warning: INFO: os::commit_memory(0x00000000e5330000, 449642496, 0) failed; error='Not enough space' (errno=12); 或者error='Cannot a ...'(errno=12);

原因：jvm要分配最大内存超出系统内存

解决：

root@localhost ~]# vim /elasticsearch-7.6.0/config/jvm.options   # 适当调整指定jvm内存，由于虚拟机内存制定1g，所以适当降低jvm内存指定，这里改成512m。
-Xms512m
-Xmx512m
[root@localhost ~]# /elasticsearch-7.6.0/bin/elasticsearch       # 重启elasticsearch

三、org.elasticsearch.bootstrap.StartupException: java.lang.IllegalStateException: failed to obtain node locks, tried [[/www/wwwroot/elasticsearch-7.6.0/data]] with lock id [0]; maybe these locations are not writable or multiple nodes were started without increasing [node.max_local_storage_nodes] (was [1])?

原因：线程占用

解决：重新启动

[root@localhost ~]# ps -ef | grep elasticsearch                 # 找到elasticsearch线程
[root@localhost ~]# kill -9 pid                                 # 杀死elasticsearch线程
[root@localhost ~]# /elasticsearch-7.6.0/bin/elasticsearch      # 重启elasticsearch

　https://www.cnblogs.com/sitongyan/p/11263753.html

https://blog.csdn.net/weixin_41238134/article/details/99291917