支付宝蚂蚁金服--大数据开发工程师面试题--输入：aaabbca，输出：3a2b1c1a

flume启动一直报错ERROR - org.apache.flume.SinkRunner$PollingRunner.run(SinkRunner.java:158)] Unable to deliver event. Exception follows.，报错详情如下2021-12-27 20:41:52,509 (SinkRunner-PollingRunner-DefaultSinkPr

解决idea 的因为lombok的报错：java: You aren't using a compiler supported by lombok, so lombok will not work and has been disabled.Your processor is: com.sun.proxy.$Proxy27Lombok supports: OpenJDK javac, ECJ

Traceback (most recent call last):File "/home/admin/apps/*-*-sync/task/__init__.py", line 114, in runfor data in self.index_data():File "/home/admin/apps/*-*-sync/task/huahuo/*_*_sync.py", line 72, in

java.lang.NoClassDefFoundError: org/apache/hadoop/hive/metastore/api/MetaException2、java.lang.NoClassDefFoundError: org/apache/thrift/TBase3、java.lang.NoClassDefFoundError:org/apache/hadoop/hive/conf/

本次安装演示是基于虚拟机的服务器（Linux）进行的，分别是：bdc112 bdc113 bdc114。 主要进行了Linux安装环境准备，远程工具：xshell和xftp安装、虚拟机的配置、虚拟机的克隆、虚拟机和我们Windows 10 的网络桥接、免密登录配置、jdk安装，hadoop安装：包括集群规划、分发脚本编写、编写hadoop常用脚本等比较详细完善的安装配置过程

linux下启动Presto报错：Cannot connect to discovery server for announce: Announcement failed for http://hadoop102:8881在虚拟机hadoop103启动时报错[lqs@hadoop103 presto]$ bin/launcher run报错内容如下：hadoop103:349662021-12-0

Communications link failureThe last packet successfully received from the server was 192 milliseconds ago.The last packet sent successfully to the server was 173 milliseconds ago.No appropriate protoc

Maven log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).log4j:WARN Please initialize the log4j system properly.log4j:WARN See http://logging.apac