1. 缺少MySQL驱动包

1.1 问题描述

Caused by: org.datanucleus.store.rdbms.connectionpool.DatastoreDriverNotFoundException: The specified datastore driver ("com.mysql.jdbc.Driver") was not found in the CLASSPATH. Please check your CLASSPATH specification, and the name of the driver.
	at org.datanucleus.store.rdbms.connectionpool.AbstractConnectionPoolFactory.loadDriver(AbstractConnectionPoolFactory.java:58)
	at org.datanucleus.store.rdbms.connectionpool.BoneCPConnectionPoolFactory.createConnectionPool(BoneCPConnectionPoolFactory.java:54)
	at org.datanucleus.store.rdbms.ConnectionFactoryImpl.generateDataSources(ConnectionFactoryImpl.java:213)

1.2. 解决方案

上述问题很可能是缺少mysql的jar包，下载mysql-connector-java-5.1.32.tar.gz，复制到hive的lib目录下：

xiaosi@yoona:~$ cp mysql-connector-java-5.1.34-bin.jar opt/hive-2.1.0/lib/

2. 元数据库mysql初始化

2.1 问题描述

运行./hive脚本时，无法进入，报错：

Exception in thread "main" java.lang.RuntimeException: Hive metastore database is not initialized. Please use schematool (e.g. ./schematool -initSchema -dbType ...) to create the schema. If needed, don't forget to include the option to auto-create the underlying database in your JDBC connection string (e.g. ?createDatabaseIfNotExist=true for mysql)

2.2 解决方案

在scripts目录下运行 schematool -initSchema -dbType mysql命令进行Hive元数据库的初始化：

xiaosi@yoona:~/opt/hive-2.1.0/scripts$  schematool -initSchema -dbType mysql
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/xiaosi/opt/hive-2.1.0/lib/log4j-slf4j-impl-2.4.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/xiaosi/opt/hadoop-2.7.3/share/hadoop/common/lib/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual binding is of type [org.apache.logging.slf4j.Log4jLoggerFactory]
Metastore connection URL:	 jdbc:mysql://localhost:3306/hive_meta?createDatabaseIfNotExist=true
Metastore Connection Driver :	 com.mysql.jdbc.Driver
Metastore connection User:	 root
Starting metastore schema initialization to 2.1.0
Initialization script hive-schema-2.1.0.mysql.sql
Initialization script completed
schemaTool completed

3. Relative path in absolute URI

3.1 问题描述

Exception in thread "main" java.lang.IllegalArgumentException: java.net.URISyntaxException: Relative path in absolute URI: ${system:java.io.tmpdir%7D/$%7Bsystem:user.name%7D
...
Caused by: java.net.URISyntaxException: Relative path in absolute URI: ${system:java.io.tmpdir%7D/$%7Bsystem:user.name%7D
	at java.net.URI.checkPath(URI.java:1823)
	at java.net.URI.<init>(URI.java:745)
	at org.apache.hadoop.fs.Path.initialize(Path.java:202)
	... 12 more

3.2 解决方案

产生上述问题的原因是使用了没有配置的变量，解决此问题只需在配置文件hive-site.xml中配置system:user.name和system:java.io.tmpdir两个变量，配置文件中就可以使用这两个变量：

<property>
    <name>system:user.name</name>
    <value>xiaosi</value>
</property>
<property>
    <name>system:java.io.tmpdir</name>
    <value>/home/${system:user.name}/tmp/hive/</value>
</property>

4. 拒绝连接

4.1 问题描述

on exception: java.net.ConnectException: 拒绝连接; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused
...
Caused by: java.net.ConnectException: Call From Qunar/127.0.0.1 to localhost:9000 failed on connection exception: java.net.ConnectException: 拒绝连接; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused
...
Caused by: java.net.ConnectException: 拒绝连接
	at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
	at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
	at org.apache.hadoop.net.SocketIOWithTimeout.connect(SocketIOWithTimeout.java:206)
	at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:531)
	at org.apache.hadoop.net.NetUtils.connect(NetUtils.java:495)
	at org.apache.hadoop.ipc.Client$Connection.setupConnection(Client.java:614)
	at org.apache.hadoop.ipc.Client$Connection.setupIOstreams(Client.java:712)
	at org.apache.hadoop.ipc.Client$Connection.access$2900(Client.java:375)
	at org.apache.hadoop.ipc.Client.getConnection(Client.java:1528)
	at org.apache.hadoop.ipc.Client.call(Client.java:1451)
	... 29 more

4.2 解决方案

有可能是Hadoop没有启动，使用jps查看一下当前进程发现：

xiaosi@yoona:~/opt/hive-2.1.0$ jps
7317 Jps

可以看见，我们确实没有启动Hadoop。开启Hadoop的NameNode和DataNode守护进程

xiaosi@yoona:~/opt/hadoop-2.7.3$ ./sbin/start-dfs.sh 
Starting namenodes on [localhost]
localhost: starting namenode, logging to /home/xiaosi/opt/hadoop-2.7.3/logs/hadoop-xiaosi-namenode-yoona.out
localhost: starting datanode, logging to /home/xiaosi/opt/hadoop-2.7.3/logs/hadoop-xiaosi-datanode-yoona.out
Starting secondary namenodes [0.0.0.0]
0.0.0.0: starting secondarynamenode, logging to /home/xiaosi/opt/hadoop-2.7.3/logs/hadoop-xiaosi-secondarynamenode-yoona.out
xiaosi@yoona:~/opt/hadoop-2.7.3$ jps
8055 Jps
7561 NameNode
7929 SecondaryNameNode
7724 DataNode

5. 创建Hive表失败

5.1 问题描述

FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. MetaException(message:For direct MetaStore DB connections, we don't support retries at the client level.)

5.2 解决方案

查看Hive日志，看到这样的错误日志：

NestedThrowablesStackTrace:
Could not create "increment"/"table" value-generation container `SEQUENCE_TABLE` since autoCreate flags do not allow it. 
org.datanucleus.exceptions.NucleusUserException: Could not create "increment"/"table" value-generation container `SEQUENCE_TABLE` since autoCreate flags do not allow it.

出现上述问题主要因为mysql的bin-log format默认为statement ，在mysql中通过 show variables like 'binlog_format'; 语句查看bin-log format的配置值

mysql> show variables like 'binlog_format';
+---------------+-----------+
| Variable_name | Value     |
+---------------+-----------+
| binlog_format | STATEMENT |
+---------------+-----------+
1 row in set (0.00 sec)

修改bin-log format的默认值，在mysql的配置文件/etc/mysql/mysql.conf.d/mysqld.cnf中添加 binlog_format="MIXED" ，重启mysql，再启动 hive即可。

mysql> show variables like 'binlog_format';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| binlog_format | MIXED |
+---------------+-------+
1 row in set (0.00 sec)

再次执行创表语句：

hive> create table  if not exists employees(
    >    name string comment '姓名',
    >    salary float comment '工资',
    >    subordinates array<string> comment '下属',
    >    deductions map<string,float> comment '扣除金额',
    >    address struct<city:string,province:string> comment '家庭住址'
    > )
    > comment '员工信息表'
    > ROW FORMAT DELIMITED 
    > FIELDS TERMINATED BY '\t'
    > LINES TERMINATED BY  '\n'
    > STORED AS TEXTFILE;
OK
Time taken: 0.664 seconds

6. 加载数据失败

6.1 问题描述

hive> load data local inpath '/home/xiaosi/hive/input/result.txt' overwrite into table recent_attention;
Loading data to table test_db.recent_attention
Failed with exception Unable to move source file:/home/xiaosi/hive/input/result.txt to destination hdfs://localhost:9000/user/hive/warehouse/test_db.db/recent_attention/result.txt
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.MoveTask

查看Hive日志，看到这样的错误日志：

Caused by: org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /home/xiaosi/hive/warehouse/recent_attention/result.txt could only be replicated to 0 nodes instead of minReplication (=1).  There are 0 datanode(s) running and no node(s) are excluded in this operation.

看到 0 datanodes running 我们猜想可能datanode挂掉了，jps验证一下，果然我们的datanode没有启动起来。

6.2 问题解决

这个问题是由于datanode没有启动导致的，至于datanode为什么没有启动起来，去看另一篇博文：那些年踩过的Hadoop坑（http://blog.csdn.net/sunnyyoona/article/details/51659080）

7. Java连接Hive 驱动失败

7.1 问题描述

java.lang.ClassNotFoundException: org.apache.hadoop.hive.jdbc.HiveDriver
	at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_91]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_91]
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331) ~[na:1.8.0_91]
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_91]
	at java.lang.Class.forName0(Native Method) ~[na:1.8.0_91]
	at java.lang.Class.forName(Class.java:264) ~[na:1.8.0_91]
	at com.sjf.open.hive.HiveClient.getConn(HiveClient.java:29) [classes/:na]
	at com.sjf.open.hive.HiveClient.run(HiveClient.java:53) [classes/:na]
	at com.sjf.open.hive.HiveClient.main(HiveClient.java:77) [classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144) [idea_rt.jar:na]

7.2 解决方案

private static String driverName = "org.apache.hadoop.hive.jdbc.HiveDriver";

取代

private static String driverName = "org.apache.hive.jdbc.HiveDriver"

8. create table问题

8.1 问题描述

create table if not exists employee(
   name string comment 'employee name',
   salary float comment 'employee salary',
   subordinates array<string> comment 'names of subordinates',
   deductions map<string,float> comment 'keys are deductions values are percentages',
   address struct<street:string, city:string, state:string, zip:int> comment 'home address'
)
comment 'description of the table'
tblproperties ('creator'='yoona','date'='20160719')
location '/user/hive/warehouse/test.db/employee';

错误信息：

FAILED: ParseException line 10:0 missing EOF at 'location' near ')'

8.2 解决方案

Location放在TBPROPERTIES之前：

create table if not exists employee(
   name string comment 'employee name',
   salary float comment 'employee salary',
   subordinates array<string> comment 'names of subordinates',
   deductions map<string,float> comment 'keys are deductions values are percentages',
   address struct<street:string, city:string, state:string, zip:int> comment 'home address'
)
comment 'description of the table'
location '/user/hive/warehouse/test.db/employee'
tblproperties ('creator'='yoona','date'='20160719');
create table命令：https://cwiki.apache.org/confluence/display/Hive/LanguageManual+DDL#LanguageManualDDL-CreateTable

9. JDBC Hive 拒绝连接

9.1 问题描述

15:00:50.815 [main] INFO  org.apache.hive.jdbc.Utils - Supplied authorities: localhost:10000
15:00:50.832 [main] INFO  org.apache.hive.jdbc.Utils - Resolved authority: localhost:10000
15:00:51.010 [main] DEBUG o.a.thrift.transport.TSaslTransport - opening transport org.apache.thrift.transport.TSaslClientTransport@3ffc5af1
15:00:51.019 [main] WARN  org.apache.hive.jdbc.HiveConnection - Failed to connect to localhost:10000
15:00:51.027 [main] ERROR com.sjf.open.hive.HiveClient - Connection error!
java.sql.SQLException: Could not open client transport with JDBC Uri: jdbc:hive2://localhost:10000/default: java.net.ConnectException: 拒绝连接
	at org.apache.hive.jdbc.HiveConnection.openTransport(HiveConnection.java:219) ~[hive-jdbc-2.1.0.jar:2.1.0]
	at org.apache.hive.jdbc.HiveConnection.<init>(HiveConnection.java:157) ~[hive-jdbc-2.1.0.jar:2.1.0]
	at org.apache.hive.jdbc.HiveDriver.connect(HiveDriver.java:107) ~[hive-jdbc-2.1.0.jar:2.1.0]
	at java.sql.DriverManager.getConnection(DriverManager.java:664) ~[na:1.8.0_91]
	at java.sql.DriverManager.getConnection(DriverManager.java:247) ~[na:1.8.0_91]
	at com.sjf.open.hive.HiveClient.getConn(HiveClient.java:29) [classes/:na]
	at com.sjf.open.hive.HiveClient.run(HiveClient.java:52) [classes/:na]
	at com.sjf.open.hive.HiveClient.main(HiveClient.java:76) [classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_91]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_91]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_91]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_91]
	at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144) [idea_rt.jar:na]
Caused by: org.apache.thrift.transport.TTransportException: java.net.ConnectException: 拒绝连接
	at org.apache.thrift.transport.TSocket.open(TSocket.java:226) ~[libthrift-0.9.3.jar:0.9.3]
	at org.apache.thrift.transport.TSaslTransport.open(TSaslTransport.java:266) ~[libthrift-0.9.3.jar:0.9.3]
	at org.apache.thrift.transport.TSaslClientTransport.open(TSaslClientTransport.java:37) ~[libthrift-0.9.3.jar:0.9.3]
	at org.apache.hive.jdbc.HiveConnection.openTransport(HiveConnection.java:195) ~[hive-jdbc-2.1.0.jar:2.1.0]
	... 12 common frames omitted
Caused by: java.net.ConnectException: 拒绝连接
	at java.net.PlainSocketImpl.socketConnect(Native Method) ~[na:1.8.0_91]
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) ~[na:1.8.0_91]
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) ~[na:1.8.0_91]
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) ~[na:1.8.0_91]
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) ~[na:1.8.0_91]
	at java.net.Socket.connect(Socket.java:589) ~[na:1.8.0_91]
	at org.apache.thrift.transport.TSocket.open(TSocket.java:221) ~[libthrift-0.9.3.jar:0.9.3]
	... 15 common frames omitted

9.2 解决方案

(1) 检查hive server2是否启动：

xiaosi@Qunar:/opt/apache-hive-2.0.0-bin/bin$ sudo netstat -anp | grep 10000

如果没有启动hive server2，首先启动服务：

xiaosi@Qunar:/opt/apache-hive-2.0.0-bin/conf$ hive --service hiveserver2 >/dev/null 2>/dev/null &
[1] 11978

(2) 检查配置：

<property>
    <name>hive.server2.thrift.port</name>
    <value>10000</value>
    <description>Port number of HiveServer2 Thrift interface when hive.server2.transport.mode is 'binary'.</description>
</property>

10. User root is not allowed to impersonate anonymous

10.1 问题描述

Failed to open new session: java.lang.RuntimeException: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.security.authorize.AuthorizationException): User:xiaosiis not allowed to impersonate anonymous

10.2 解决方案

修改hadoop 配置文件 etc/hadoop/core-site.xml,加入如下配置项

<property>
    <name>hadoop.proxyuser.root.hosts</name>
    <value>*</value>
</property>
<property>
    <name>hadoop.proxyuser.root.groups</name>
    <value>*</value>
</property>

备注

hadoop.proxyuser.XXX.hosts 与 hadoop.proxyuser.XXX.groups 中XXX为异常信息中User:* 中的用户名部分

<property> 
    <name>hadoop.proxyuser.xiaosi.hosts</name> 
    <value>*</value> 
    <description>The superuser can connect only from host1 and host2 to impersonate a user</description>
</property> 
<property> 
    <name>hadoop.proxyuser.xiaosi.groups</name> 
    <value>*</value> 
    <description>Allow the superuser oozie to impersonate any members of the group group1 and group2</description>
</property>

11. 安全模式

11.1 问题描述

Caused by: org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.hdfs.server.namenode.SafeModeException): Cannot create directory /tmp/hive/xiaosi/c2f6130d-3207-4360-8734-dba0462bd76c. Name node is in safe mode.
The reported blocks 22 has reached the threshold 0.9990 of total blocks 22. The number of live datanodes 1 has reached the minimum number 0. In safe mode extension. Safe mode will be turned off automatically in 5 seconds.
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkNameNodeSafeMode(FSNamesystem.java:1327)
	at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesystem.java:3893)
	at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameNodeRpcServer.java:983)
	at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTranslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:622)
	at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$ClientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:616)
	at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:969)
	at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2049)
	at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:2045)
	at java.security.AccessController.doPrivileged(Native Method)
	at javax.security.auth.Subject.doAs(Subject.java:415)
	at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1657)
	at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2043)
	at org.apache.hadoop.ipc.Client.call(Client.java:1475)
	at org.apache.hadoop.ipc.Client.call(Client.java:1412)
	at org.apache.hadoop.ipc.ProtobufRpcEngine$Invoker.invoke(ProtobufRpcEngine.java:229)
	at com.sun.proxy.$Proxy32.mkdirs(Unknown Source)
	at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolTranslatorPB.mkdirs(ClientNamenodeProtocolTranslatorPB.java:558)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.hadoop.io.retry.RetryInvocationHandler.invokeMethod(RetryInvocationHandler.java:191)
	at org.apache.hadoop.io.retry.RetryInvocationHandler.invoke(RetryInvocationHandler.java:102)
	at com.sun.proxy.$Proxy33.mkdirs(Unknown Source)
	at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:3000)
	at org.apache.hadoop.hdfs.DFSClient.mkdirs(DFSClient.java:2970)
	at org.apache.hadoop.hdfs.DistributedFileSystem$21.doCall(DistributedFileSystem.java:1047)
	at org.apache.hadoop.hdfs.DistributedFileSystem$21.doCall(DistributedFileSystem.java:1043)
	at org.apache.hadoop.fs.FileSystemLinkResolver.resolve(FileSystemLinkResolver.java:81)
	at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirsInternal(DistributedFileSystem.java:1043)
	at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirs(DistributedFileSystem.java:1036)
	at org.apache.hadoop.hive.ql.session.SessionState.createPath(SessionState.java:682)
	at org.apache.hadoop.hive.ql.session.SessionState.createSessionDirs(SessionState.java:617)
	at org.apache.hadoop.hive.ql.session.SessionState.start(SessionState.java:526)
	... 9 more

11.2 问题分析

hdfs在启动开始时会进入安全模式，这时文件系统中的内容不允许修改也不允许删除，直到安全模式结束。安全模式主要是为了系统启动的时候检查各个DataNode上数据块的有效性，同时根据策略必要的复制或者删除部分数据块。运行期通过命令也可以进入安全模式。在实践过程中，系统启动的时候去修改和删除文件也会有安全模式不允许修改的出错提示，只需要等待一会儿即可。

11.3 问题解决

可以等待其自动退出安全模式，也可以使用手动命令来离开安全模式：

xiaosi@yoona:~$ hdfs dfsadmin -safemode leave
Safe mode is OFF