多租户是CDH里面非常重要的一部分，从一开始配置KDC到集成KDC，服务使用过程中都有可能会遇到各种各样的问题；下面我举例说下我当时遇过的问题，希望能帮助到大家
服务启动错误
KDC服务配置完成安装完成，CDH集成过程中也没问题，CDH启动过程完客户端执行kinit的时候也没有问题，但一旦用hadoop fs -/s hadoop命令就报以下错误
SIMPLE authentication is not enabled. Available:[TOKEN, KERBEROS]
百思不得其解的情况下去看了namenode启动脚本，发现里面会首先加载环境变量为 $HADOOP_CONF_DIR里面的配置文件.xml
接着输入命令 echo $HADOOP_CONF_DIR，发现有值
vi /etc/profile发现以下配置
企业微信截图_15281173461421.png
大坑啊~~~~，hdfs启动一直加载这个目录下的配置文件，而不是加载cdh前端生成的配置文件，导致hadoop fs 命令一直发送simple请求而不是kerberos请求
服务使用问题
CDH集成Kerberos + Sentry后，由于部分用户有权限登陆linux直接使用服务，偶尔他们会用hive client使用hive服务，这时候你会发现 sentry权限控制对hive client不生效
kinit deng_yb，该账号之前做了权限控制
登陆hive clinet看到的效果
[root@bi-master ~]# klist
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: deng_yb@WONHIGH.COM
Valid starting Expires Service principal
06/07/18 20:40:52 06/08/18 20:40:52 krbtgt/WONHIGH.COM@WONHIGH.COM
renew until 06/14/18 20:40:52
[root@bi-master ~]# hive
Java HotSpot™ 64-Bit Server VM warning: ignoring option MaxPermSize=512M; support was removed in 8.0
Java HotSpot™ 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
Java HotSpot™ 64-Bit Server VM warning: ignoring option MaxPermSize=512M; support was removed in 8.0
Logging initialized using configuration in jar:file:/opt/cloudera/parcels/CDH-5.11.0-1.cdh5.11.0.p0.34/jars/hive-common-1.1.0-cdh5.11.0.jar!/hive-log4j.properties
sWARNING: Hive CLI is deprecated and migration to Beeline is recommended.
hive> show databases;
OK
bi
default
gms
gtp
gtp_data
gtp_dc
gtp_test
gtp_txt
kudu_raw
kudu_test
kudu_vip
Time taken: 3.417 seconds, Fetched: 11 row(s)
所有库的信息都看到了~~~~~
同样账号。在beeline看到的是
Last login: Thu Jun 7 21:48:31 2018 from 10.230.71.245
[root@bi-master ~]# klist
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: deng_yb@WONHIGH.COM
Valid starting Expires Service principal
06/07/18 20:40:52 06/08/18 20:40:52 krbtgt/WONHIGH.COM@WONHIGH.COM
renew until 06/14/18 20:40:52
[root@bi-master ~]# beeline
Java HotSpot™ 64-Bit Server VM warning: ignoring option MaxPermSize=512M; support was removed in 8.0
Java HotSpot™ 64-Bit Server VM warning: Using incremental CMS is deprecated and will likely be removed in a future release
Java HotSpot™ 64-Bit Server VM warning: ignoring option MaxPermSize=512M; support was removed in 8.0
Beeline version 1.1.0-cdh5.11.0 by Apache Hive
beeline> !connect jdbc:hive2://localhost:10000/;principal=hive/bi-master@WONHIGH.COM
scan complete in 9ms
Connecting to jdbc:hive2://localhost:10000/;principal=hive/bi-master@WONHIGH.COM
Connected to: Apache Hive (version 1.1.0-cdh5.11.0)
Driver: Hive JDBC (version 1.1.0-cdh5.11.0)
Transaction isolation: TRANSACTION_REPEATABLE_READ
0: jdbc:hive2://localhost:10000/> show databases;
INFO : Compiling command(queryId=hive_20180607220303_1319b1e8-5ec3-477b-836e-2a279b566ef4): show databases
INFO : Semantic Analysis Completed
INFO : Returning Hive schema: Schema(fieldSchemas:[FieldSchema(name:database_name, type:string, comment:from deserializer)], properties:null)
INFO : Completed compiling command(queryId=hive_20180607220303_1319b1e8-5ec3-477b-836e-2a279b566ef4); Time taken: 1.87 seconds
INFO : Executing command(queryId=hive_20180607220303_1319b1e8-5ec3-477b-836e-2a279b566ef4): show databases
INFO : Starting task [Stage-0:DDL] in serial mode
INFO : Completed executing command(queryId=hive_20180607220303_1319b1e8-5ec3-477b-836e-2a279b566ef4); Time taken: 0.835 seconds
INFO : OK
±---------------±-+
| database_name |
±---------------±-+
| bi |
| default |
±---------------±-+
3 rows selected (4.704 seconds
只能看到部分库的信息
因此hive client看到的东西不受sentry控制
但之前我们通过hadoop fs -ls 命令是看不到其他用户目录的下的文件，是否意味着就算通过在hive clinet看到所有东西(metainfo)，超出自身权限的数据(data)是看不到的？
#随便查个不是自己权限下的表信息
Time taken: 0.076 seconds, Fetched: 114 row(s)
hive> select * from ods_item;
FAILED: SemanticException Unable to determine if hdfs://bi-master:8020/user/hive/warehouse/gtp.db/ods_item is encrypted: org.apache.hadoop.security.AccessControlException: Permission denied: user=deng_yb, access=READ, inode="/user/hive/warehouse/gtp.db/ods_item":hive:hive:drwxrwx–x
at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkAccessAcl(DefaultAuthorizationProvider.java:363)
at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.check(DefaultAuthorizationProvider.java:256)
at org.apache.hadoop.hdfs.server.namenode.DefaultAuthorizationProvider.checkPermission(DefaultAuthorizationProvider.java:168)
at org.apache.sentry.hdfs.SentryAuthorizationProvider.checkPermission(SentryAuthorizationProvider.java:178)
at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermission(FSPermissionChecker.java:152)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:3529)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPermission(FSDirectory.java:3512)
at org.apache.hadoop.hdfs.server.namenode.FSDirectory.checkPathAccess(FSDirectory.java:3483)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkPathAccess(FSNamesystem.java:6588)
at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.getEZForPath(FSNamesystem.java:9282)
at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.getEZForPath(NameNodeRpcServer.java:1635)
at org.apache.hadoop.hdfs.server.namenode.AuthorizationProviderProxyClientProtocol.getEZForPath(AuthorizationProviderProxyClientProtocol.java:928)
at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.getEZForPath(ClientNamenodeProtocolServerSideTranslatorPB.java:1360)
at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocolServer
Server.call(RPC.java:1073)
at org.apache.hadoop.ipc.Server$HandlerHandler
Handler.run(Server.java:2214)
因此实际上，真实数据是看不到的，假如你不介意的话；就这样也没关系
介意的话，可以在cm上面hive配置设置白名单用户
hive_allowed.png
这样其他用户想查看库和表信息就会报错
MapReduce使用问题
我们在用sqoop从oracle导数到hive过程中，报类似这样的错
Requested user deng_yb is not whitelisted and has id 501,whichis below the minimum allowed 1000
Failing this attempt. Failing the application.
17/09/02 20:05:04 INFO mapreduce.Job: Counters: 0
Job Finished in 6.184 seconds
那是因为Yarn限制了用户id小于10000的用户提交作业；Yarn的min.user.id改为0即可
to_zero.png
重启yarn
部分用户想用hdfs账号做MapReduce操作，有可能遇到下面错误
Diagnostics: Application application_1528344974377_0009 initialization failed (exitCode=255) with output: main : command provided 0
main : run as user is hdfs
main : requested yarn user is hdfs
Requested user hdfs is banned
这是因为yarn禁止了hdfs用户调度资源，解决方案如下:
yarn_ban_user.png
把hdfs这行删了就好，重启问题解决
impala问提
部分节点集成kerberos后启动impala daemon报错，类似以下错误
(SASL(-4): no mechanism available: No worthy mechs found)
这时候在报错的节点安装以下
yum install cyrus-sasl-plain cyrus-sasl-devel cyrus-sasl-gssapi
重启
kafka使用问题
kafka集成kerberos解决办法可以参考
https://www.jianshu.com/p/dd73b318e743
impala jdbc使用问题
impala jdbc集成kerberos认证可以参考
https://www.jianshu.com/p/62aa4f9e0615
