跨域问题
跨域前端遇到的问题: Access to XMLHttpRequest at ‘http://www.xxx.xxxx/api/x/d/xc’ from origin ‘http://127.0.0.1:3000’ has been blocked by cors policy: No ‘Access-Contorl-Allow-Origin’ header is present on the requested resource. …
达梦数据库导入导出工具dmfldr
基础信息
OS版本:
Red Hat Enterprise Linux Server release 7.9 (Maipo)
DB版本:
DM Database Server 64 V8
DB Version: 0x7000c
03134284132-20240115-215128-200811 dmfldr工具介绍
dmfldr(DM Fast Loade…
问题:root.users.hdfs is not a leaf queue
CDH集群报错:
Exception in thread “main” org.apache.hadoop.yarn.exceptions.YarnException: Failed to submit application_1713149630679_0005 to YARN : root.users.hdfs is not a leaf queue 思路
…
目录 Day 13:多线程(11)常见的锁策略1. 悲观锁 vs 乐观锁2. 重量级锁 vs 轻量级锁3. 自旋锁 vs 挂起等待锁4. 可重入锁 vs 不可重入锁5. 公平锁 vs 非公平锁6. 互斥锁 vs 读写锁 synchronized实现原理1. 锁升级2. 锁消除3. 锁粗化 CAS Day 13…