安装MySQL-server出现如下[root@mastermysql]#rpm-ivhMySQL-server-5.6.24-1.el6.x86_64.rpm准备中...#################################[100%]file/usr/share/mysql/charsets/READMEfrominstallofMySQL-server-5.6.24-1.el6.x86_64conflictswithfilefrompackagemariadb-libs-1:5.5.64-1.el7.x86_64file/usr/share/mysql/czech/errmsg.sysfrominstallofMySQL-server-5.6.24-1.el6.x86_64conflictswithfilefrompackagemariadb-libs-1:5.5.64-1.el7.x86_64file/usr/share/mysql/danish/errmsg.sysfrominstallofMySQL-server-5.6.24-1.el6.x86_64conflictswithfilefrompackagemariadb-libs-1:5.5.64-1.el7.x86_64file/usr/share/mysql/dutch/errmsg.sysfrominstallofMySQL-server-5.6.24-1.el6.x86_64conflictswithfilefrompackagemariadb-libs-1:5.5.64-1.el7.x86_64file/usr/share/mysql/english/errmsg.sysfrominstallofMySQL-server-5.6.24-1.el6.x86_64conflictswithfilefrompackagemariadb-libs-1:5.5.64-1.el7.x86_64......原因是系统已经安装了其他版本的mysql-libs包导致不兼容。可以使用命令查看yumlist|grepmysql，查看之前安装的mysql的信息将之前的mysql的lib包删除了即可，删除mysql-libsyumremovemysql-libs安装MySQL没有临时密码centos7通过yum装完mysql5.7，找不到root密码原因是原来安装过mysql残留有数据#第一步删除残留文件[root@master~]rm-rf/var/lib/mysql#第二部启动MySQL服务[root@master~]systemctlrestartmysqld#查看密码[root@master~]grep'temporarypassword'/var/log/mysqld.log
name文件夹不存在错误描述：Directory/usr/local/src/hadoop/tmp/dfs/nameisinaninconsistentstate:storagedirectorydoesnotexistorisnotaccessible.处理方法：创建name文件重新格式化再次启动namenode无法启动错误描述：当把hadoop停止之后，再次启动没有namenode节点处理方法：清空临时目录tmp里面的data下的东西,再次启动namenode处于安全模式错误描述Namenodeisinsafemode.Namenode处于安全模式处理方式：关闭安全模式hadoopdfsadmin-safemodeleave进入安全模式hadoopdfsadmin-safemodeenterHive无法跑MR任务错误描述Taskwiththemostfailures(4):-----TaskID:task_1594519690907_0001_m_000000URL:http://0.0.0.0:8088/taskdetails.jsp?jobid=job_1594519690907_0001&tipid=task_1594519690907_0001_m_000000-----DiagnosticMessagesforthisTask:Containerlaunchfailedforcontainer_1594519690907_0002_01_000005:org.apache.hadoop.yarn.exceptions.InvalidAuxServiceException:TheauxService:mapreduce_shuffledoesnotexistatsun.reflect.NativeConstructorAccessorImpl.newInstance0(NativeMethod)atsun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)atsun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)atjava.lang.reflect.Constructor.newInstance(Constructor.java:423)atorg.apache.hadoop.yarn.api.records.impl.pb.SerializedExceptionPBImpl.instantiateExceptionImpl(SerializedExceptionPBImpl.java:171)atorg.apache.hadoop.yarn.api.records.impl.pb.SerializedExceptionPBImpl.instantiateException(SerializedExceptionPBImpl.java:182)atorg.apache.hadoop.yarn.api.records.impl.pb.SerializedExceptionPBImpl.deSerialize(SerializedExceptionPBImpl.java:106)atorg.apache.hadoop.mapreduce.v2.app.launcher.ContainerLauncherImpl$Container.launch(ContainerLauncherImpl.java:162)atorg.apache.hadoop.mapreduce.v2.app.launcher.ContainerLauncherImpl$EventProcessor.run(ContainerLauncherImpl.java:393)atjava.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)atjava.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)atjava.lang.Thread.run(Thread.java:748)FAILED:ExecutionError,returncode2fromorg.apache.hadoop.hive.ql.exec.mr.MapRedTaskMapReduceJobsLaunched:Stage-Stage-1:Map:1Reduce:1HDFSRead:0HDFSWrite:0FAILTotalMapReduceCPUTimeSpent:0msec处理方式：#确认yarn-site.xml的配置是否正确<!--NodeManager获取数据的方式--><property><name>yarn.nodemanager.aux-services</name><value>mapreduce_shuffle</value></property>#然后重启Hadoop