后儿就放假了，上班这心真心收不住，为了能充实的度过这难熬的两天，我决定搞个大工程。。。。。ps：我为啥这么期待放假呢，在沙发上像死人一样躺一天真的有意义嘛。。。。。。。
当然版本：hadoop2.3.0cdh5.0.2
机器：
| nn | dn | jn | rm | nm | jh | hmaster | hregionserver | |
| mast1 | 是 | 是 | 是 | 是 | 是 | 是 | 是 | |
| mast2 | 是 | 是 | 是 | 是 | 是 | 是 | 是 | |
| mast3 | 是 | 是 | 是 | 是 | 是 |
目标版本：hadoop2.6.0cdh5.7.0
升级方式：Upgrading Unmanaged CDH Using the Command Line
升级注意事项：①从低于cdh5.4.0升级到cdh5.4.0或更高版本，需要进行hdfs元数据升级；
②从低于cdh5.2.0版本升级需要做如下升级：升级hdfs元数据
升级Sentry database
升级hive数据库
升级sqoop2数据库
③另外还要确保如下升级：升级Oozie数据库和共享数据库
如果向hdfs上传了spark集合jar文件，要上传文件的最新版本
升级步骤：
1.为升级做准备：
①使namenode进入安全模式，备份fsimage
[hadoop@mast1 conf]$ hdfs haadmin -getServiceState mast1
active
[hadoop@mast1 conf]$ hdfs dfsadmin -safemode enter
Safe mode is ON
[hadoop@mast1 conf]$ hdfs dfsadmin -saveNamespace
②确认无hadoop服务在运行
[root@mast1 ~]# ps -aef|grep java
root 9540 8838 0 15:34 pts/0 00:00:00 grep java
③在namenode（ha中active的namenode）中备份元数据（注意过程中如果发现lock文件，则从头开始再执行一遍）
[root@mast1 ~]# cd /app/hdp/dfs/name
[root@mast1 name]# tar -cvf /root/nn_backup_data.tar .
./
./edits/
./edits/current/
./edits/current/edits_inprogress_0000000000000000624
./edits/current/edits_0000000000000000413-0000000000000000533
./edits/current/edits_0000000000000000620-0000000000000000621
./edits/current/edits_0000000000000000618-0000000000000000619
./edits/current/edits_0000000000000000062-0000000000000000180
./edits/current/edits_0000000000000000622-0000000000000000623
./edits/current/edits_0000000000000000038-0000000000000000050
./edits/current/edits_0000000000000000534-0000000000000000615
./edits/current/edits_0000000000000000181-0000000000000000182
./edits/current/edits_0000000000000000284-0000000000000000412
./edits/current/edits_0000000000000000051-0000000000000000061
./edits/current/seen_txid
./edits/current/edits_0000000000000000183-0000000000000000283
./edits/current/VERSION
./edits/current/edits_0000000000000000616-0000000000000000617
./current/
./current/fsimage_0000000000000000000
./current/seen_txid
./current/VERSION
./current/fsimage_0000000000000000000.md5
./namesecondary/
2.下载CDH 5 "1-click" repository
https://archive.cloudera.com/cdh5/one-click-install/redhat/6/x86_64/cloudera-cdh-5-0.x86_64.rpm
3.更新