1.先检查防火墙(关闭防火墙)
sudo ufw disable
2.内存不足（修改yarn-site.xml)
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>1024</value>
</property>
3.端口占用：
netstat anp |grep 端口号
如果有进程占用这个端口，kill -9 这个进程
重新启动即可
4.yarn-nm-recovery/yarn-nm-state/LOCK ：permission denied IO权限不够
chown -R hdfs:hdfs /usr/local/hadoop/share/hadoop/hdfs
chown -R httpfs.httpfs /usr/local/hadoop/share/hadoop/httpfs
chown -R kms.kms /usr/local/hadoop/share/hadoop/kms
chown -R mapred:mapred /usr/local/hadoop/share/hadoop/mapred
chown -R yarn:yarn /usr/local/hadoop/share/hadoop/yarn
chmod -R 755 /usr/local/hadoop-*
4.yarn-nm-recovery/yarn-nm-state/LOCK: No such file or directory
5.cpu核数过多
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>你的cpu个数</value>
</property>
