Hive Server 2 调研，安装和部署
背景
我们使用Hive Server 1已经很长时间了，用户ad-hoc query，hive-web, wormhole，运营工具等都是通过hive server来提交语句。但是hive server极其不稳定，经常会莫名奇妙假死，导致client端所有的connection都被block住了。对此我们不得不配置一个crontab检查脚本，会不断执行"show tables"语句来检测server是否假死，如果假死，只能杀死daemon进程重启。另外Hive Server 1的concurrency支持不好，如果一个用户在连接中设置了一些环境变量，绑定到一个thrift worker thread, 用户断开连接，另一个用户也创建了一个连接，他有可能也被分配到之前的worker thread，会复用之前的配置。这是因为thrift不支持检测client是否断开链接，它也就无法清除session状态信息。同时session绑定到worker thread的方式很难做HA。Hive Server 2中已经完美支持了session, client端每次RPC call的时候会带上一个SessionID, Server端会mapping到保存状态信息的Session State，使得任何一个worker thread都可以执行同一个Session的不同语句，而不会绑死在同一个上。
Hive 0.11 包含了Hive Server 1 和 Hive Server 2，还包含1的原因是为了做到向下兼容性。从长远来看都会以Hive Server 2作为首选。
配置
1. 配置hive server监听端口和Host
hive.server2.thrift.port
10000
hive.server2.thrift.bind.host
test84.hadoop
2. 配置kerberos认证，这样thrift client与hive server 2, hive server 2与hdfs交互 都由kerberos作认证
hive.server2.authentication
KERBEROS
Client authentication types.
NONE: no authentication check
LDAP: LDAP/AD based authentication
KERBEROS: Kerberos/GSSAPI authentication
CUSTOM: Custom authentication provider
(Use with property hive.server2.custom.authentication.class)
hive.server2.authentication.kerberos.principal
hadoop/[email protected]
hive.server2.authentication.kerberos.keytab
/etc/hadoop.keytab
3. 设置impersonation，这样hive server会以提交用户的身份去执行语句，如果设置为false，则会以起hive server daemon的admin user来执行语句
hive.server2.enable.doAs
true
执行命令$HIVE_HOME/bin/hive --service hiveserver2或者 $HIVE_HOME/bin/hiveserver2 会调用org.apache.hive.service.server.HiveServer2的main方法来启动
hive log中输出日志信息如下：
2013-09-17 14:59:21,081 INFO server.HiveServer2 (HiveStringUtils.java:startupShutdownMessage(604)) - STARTUP_MSG:
/************************************************************
STARTUP_MSG: Starting HiveServer2
STARTUP_MSG: host = test84.hadoop/10.1.77.84
STARTUP_MSG: args = []
STARTUP_MSG: version = 0.11.0
STARTUP_MSG: classpath = 略.................
2013-09-17 14:59:21,957 INFO security.UserGroupInformation (UserGroupInformation.java:loginUserFromKeytab(633)) - Login successful for user hadoop/[email protected] using keytab file /etc/hadoop.keytab
2013-09-17 14:59:21,958 INFO service.AbstractService (AbstractService.java:init(89)) - Service:OperationManager is inited.
2013-09-17 14:59:21,958 INFO service.AbstractService (AbstractService.java:init(89)) - Service:SessionManager is inited.
2013-09-17 14:59:21,958 INFO service.AbstractService (AbstractService.java:init(89)) - Service:CLIService is inited.
2013-09-17 14:59:21,959 INFO service.AbstractService (AbstractService.java:init(89)) - Service:ThriftCLIService is inited.
2013-09-17 14:59:21,959 INFO service.AbstractService (AbstractService.java:init(89)) - Service:HiveServer2 is inited.
2013-09-17 14:59:21,959 INFO service.AbstractService (AbstractService.java:start(104)) - Service:OperationManager is started.
2013-09-17 14:59:21,960 INFO service.AbstractService (AbstractService.java:start(104)) - Service:SessionManager is started.
2013-09-17 14:59:21,960 INFO service.AbstractService (AbstractService.java:start(104)) - Service:CLIService is started.
2013-09-17 14:59:22,007 INFO metastore.HiveMetaStore (HiveMetaStore.java:newRawStore(409)) - 0: Opening raw store with implemenation class:org.apache.hadoop.hive.metastore.ObjectStore
2013-09-17 14:59:22,032 INFO metastore.ObjectStore (ObjectStore.java:initialize(222)) - ObjectStore, initialize called
2013-09-17 14:59:22,955 INFO metastore.ObjectStore (ObjectStore.java:getPMF(267)) - Setting MetaStore object pin classes with hive.metastore.cache.pinobjtypes="Table,StorageDescriptor,SerDeInfo,Partition,Database,Type,FieldSchema,Order"
2013-09-17 14:59:23,000 INFO metastore.ObjectStore (ObjectStore.java:setConf(205)) - Initialized ObjectStore
2013-09-17 14:59:23,909 INFO metastore.HiveMetaStore (HiveMetaStore.java:logInfo(452)) - 0: get_databases: default
2013-09-17 14:59:23,912 INFO HiveMetaStore.audit (HiveMetaStore.java:logAuditEvent(238)) - ugi=hadoop/[email protected] ip=unknown-ip-addr cmd=get_databases: default
2013-09-17 14:59:23,933 INFO service.AbstractService (AbstractService.java:start(104)) - Service:ThriftCLIService is started.
2013-09-17 14:59:23,948 INFO service.AbstractService (AbstractService.java:start(104)) - Service:HiveServer2 is started.
2013-09-17 14:59:24,025 INFO security.UserGroupInformation (UserGroupInformation.java:loginUserFromKeytab(633)) - Login successful for user hadoop/[email protected] using keytab file /etc/hadoop.keytab
2013-09-17 14:59:24,047 INFO thrift.ThriftCLIService (ThriftCLIService.java:run(435)) - ThriftCLIService listening on test84.hadoop/10.1.77.84:10000
另外Hadoop FileSystem Cache会以uri schema, authority, ugi(CurrentUser)和unique的组合作为Key来缓存文件系统对象。但是这会导致hive server memory leak，通过"jmap -histo pid"可以看出filesystem对象数量和所占空间非常大，所以需要在启动hive server的时候加上disable file system cache的参数。
$HIVE_HOME/bin/hive --service hiveserver2 --hiveconf fs.hdfs.impl.disable.cache=true --hiveconf fs.file.impl.disable.cache=true
1. Beeline访问hive server 2
Beeline是hive 0.11引入的新的交互式CLI，它基于SQLLine，可以作为Hive JDBC Client端访问Hive Server 2，启动一个beeline就是维护了一个session。
由于采用了kerberos认证方式，所以需要在本地有kerberos ticket，并且在connection url中指定hive server 2的service principal，此处为principal=hadoop/[email protected]，另外用户名和密码可以不用填写，之后的语句会以当前ticket cache中principal的用户身份来执行。
-dpsh-3.2$ bin/beeline
Beeline version 0.11.0 by Apache Hive
beeline> !connect jdbc:hive2://test84.hadoop:10000/default;principal=hadoop/[email protected]
scan complete in 2ms
Connecting to jdbc:hive2://test84.hadoop:10000/default;principal=hadoop/[email protected]
Enter username for jdbc:hive2://test84.hadoop:10000/default;principal=hadoop/[email protected]:
Enter password for jdbc:hive2://test84.hadoop:10000/default;principal=hadoop/[email protected]:
Connected to: Hive (version 0.11.0)
Driver: Hive (version 0.11.0)
Transaction isolation: TRANSACTION_REPEATABLE_READ
0: jdbc:hive2://test84.hadoop:10000/default> select count(1) from abc;
+------+
| _c0 |
+------+
| 0 |
+------+
1 row selected (29.277 seconds)
0: jdbc:hive2://test84.hadoop:10000/default> !q
Closing: org.apache.hive.jdbc.HiveConnection
ps : 用下来有点不太爽的是执行mapreduce job时候没有执行过程信息，如果是一个执行时间很长的语句，会等很久而没有任何信息反馈。
2. JDBC方式
hive server 1的driver classname是org.apache.hadoop.hive.jdbc.HiveDriver，Hive Server 2的是org.apache.hive.jdbc.HiveDriver，这两个容易混淆。
另外可以在connectionUrl中指定HiveConf param和变量，params之间用';'分割，params和variables用'#'来隔开。这些都是session级别的，hive在建立完session后，会首先执行set hiveconf key value语句。
比如:
1. 带hiveconf和variables: jdbc:hive2://test84.hadoop:10000/default?hive.cli.conf.printheader=true#stab=salesTable;icol=customerID
2. 带variables: jdbc:hive2://test84.hadoop:10000/default;user=foo;password=bar
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
public class HiveTest {
public static void main(String[] args) throws SQLException {
try {
Class.forName("org.apache.hive.jdbc.HiveDriver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
Connection conn = DriverManager
.getConnection(
"jdbc:hive2://test84.hadoop:10000/default;principal=hadoop/[email protected]",
"", "");
Statement stmt = conn.createStatement();
String sql = "select * from abc";
System.out.println("Running: " + sql);
ResultSet res = stmt.executeQuery(sql);
ResultSetMetaData rsmd = res.getMetaData();
int columnCount = rsmd.getColumnCount();
for (int i = 1; i <= columnCount; i++) {
System.out.println(rsmd.getColumnTypeName(i) + ":"
+ rsmd.getColumnName(i));
}
while (res.next()) {
System.out.println(String.valueOf(res.getInt(1)) + "\t"
+ res.getString(2));
}
}
}
HiveStatement现在支持取消语句，调用Statement.cancel()会终止并销毁正在执行中的driver
注：如果kerberos认证有问题的话，可以在起client jvm时候增加JVM option "-Dsun.security.krb5.debug=true"来查看详细信息
参考链接：
https://cwiki.apache.org/confluence/display/Hive/Setting+up+HiveServer2
https://github.com/apache/hive/blob/trunk/service/if/TCLIService.thrift
http://blog.cloudera.com/blog/2013/07/how-hiveserver2-brings-security-and-concurrency-to-apache-hive/
本文链接http://blog.csdn.net/lalaguozhe/article/details/11776055，转载请注明