翻译: https://www.cloudera.com/documentation/enterprise/latest/topics/cdh_ig_hive_schema_tool.html
版本: 5.14.2
使用Hive命令行 schematool 为非托管集群升级或验证Hive Metastore数据库schema 。
注意:
如果您正在使用Cloudera Manager来管理群集,则schematool 也可以在Hive服务页面中验证或升级Metastore:
- 从Cloudera Manager管理控制台中,选择Hive服务。
- 要验证架构,请在Hive服务页面上单击Actions ,然后选择Validate Hive Metastore Schema。
- 升级模式:
- 在Hive服务页面上,单击Actions ,然后选择 停止服务。
- 仍然在Hive服务页面上,单击Actions ,然后选择升级Hive数据库Metastore架构。
- 升级完成后,重新启动服务。
继续阅读:
Schema版本Verification 和Validation
Hive将schema 版本记录在Metastore数据库中,并验证Metastore schema版本是否与即将访问Metastore的Hive二进制文件兼容。隐式创建或更改现有schema的Hive配置属性在默认情况下处于禁用状态。因此,Hive不会尝试隐式更改Metastore schema 。当您对schema 未初始化或 旧schema的Metastore执行Hive查询时,它无法访问Metastore,并且错误日志中会显示与以下示例类似的条目:
...
Caused by: MetaException(message:Version information not found in metastore. )
at org.apache.hadoop.hive.metastore.ObjectStore.checkSchema(ObjectStore.java:5638)
...
使用Hive schematool 通过初始化schema或升级它来修复导致此错误的条件。
使用schematool
使用Hive schematool 为当前Hive版本初始化Metastore schema 或从旧版本升级架构。如果该工具在该处可用,该工具将尝试从Metastore中查找当前schema。
schematool 确定初始化或升级schema所需的SQL脚本,然后在Metastore数据库执行这些脚本。Metabase数据库连接信息(如JDBC URL,JDBC驱动程序和数据库凭证)从Hive配置中提取。如果需要,您可以提供备用数据库凭据。
以下选项是schematool 其中的一部分:
$ schematool -help
usage: schemaTool
-dbType <databaseType> Metastore database type
-dryRun List SQL scripts (no execute)
-help Print this message
-info Show config and schema details
-initSchema Schema initialization
-initSchemaTo <initTo> Schema initialization to a version
-passWord <password> Override config file password
-upgradeSchema Schema upgrade
-upgradeSchemaFrom <upgradeFrom> Schema upgrade from a version
-userName <user> Override config file user name
-validate Validate the database
-verbose Only print SQL statements
dbType 选项必须始终指定,并且可以是以下之一:
derby|mysql|postgres|oracle
先决条件配置
在你使用schematool之前 ,您必须将以下属性添加到/etc/hive/conf/hive-site.xml 文件:
- javax.jdo.option.ConnectionURL
- javax.jdo.option.ConnectionDriverName
例如,以下 hive-site.xml, 如果您使用MySQL数据库作为您的Hive Metastore,hive1 是数据库用户名:
<property>
<name>javax.jdo.option.ConnectionURL</name>
<value>jdbc:mysql://my_cluster.com:3306/hive1?useUnicode=true&characterEncoding=UTF-8</value>
</property>
<property>
<name>javax.jdo.option.ConnectionDriverName</name>
<value>com.mysql.jdbc.Driver</value>
</property>
用法示例
使用 schematool 命令行工具,导航到它所在的目录:
如果您使用parcel安装CDH,schematool 通常位于:/opt/cloudera/parcels/CDH/lib/hive/bin/schematool
如果您使用软件包安装CDH, schematool 通常位于:/usr/lib/hive/bin/schematool
找到可执行文件后,可以使用 schematool 执行以下操作:
- 使用initSchema 将您的Metastore初始化为新的Hive。
$ schematool -dbType mysql -initSchema -passWord <db_user_pswd> -userName
<db_user_name>
Metastore connection URL:
jdbc:mysql://<cluster_address>:3306/<user_name>?useUnicode=true&characterEncoding=UTF-8
Metastore Connection Driver : com.mysql.jdbc.Driver
Metastore connection User: <user_name>
Starting metastore schema initialization to <new_version>
Initialization script hive-schema-<new_version_number>.mysql.sql
Initialization script completed
schemaTool completed
- 使用info 获取模式信息。
$ schematool -dbType mysql -info -passWord <db_user_pswd> -userName
<db_user_name>
Metastore connection URL:
jdbc:mysql://<cluster_address>:3306/<user_name>?useUnicode=true&characterEncoding=UTF-8
Metastore Connection Driver : com.mysql.jdbc.Driver
Metastore connection User: <user_name>
Hive distribution version: <new_version>
Required schema version: <new_version>
Metastore schema version: <new_version>
schemaTool completed
- 如果您尝试从未存储版本信息的旧版metastore获取架构信息,或者架构未初始化,则该工具将按如下所示报告错误。
$ schematool -dbType mysql -info -passWord <db_user_pswd> -userName
<db_user_name>
Metastore connection URL:
jdbc:mysql://<cluster_address>:3306/<user_name>?useUnicode=true&characterEncoding=UTF-8
Metastore Connection Driver : com.mysql.jdbc.Driver
Metastore connection User: <user_name>
Hive distribution version: <new_version>
Required schema version: <new_version>
org.apache.hadoop.hive.metastore.HiveMetaException: Failed to get schema version,
Cause:<cause_description>
*** schemaTool failed ***
- 您可以通过指定特定发行版来升级架构 -upgradeSchemaFrom 。-upgradeSchemaFrom选项需要Hive版本而不是CDH版本。有关每个CDH版本附带哪个Hive版本的信息,请参阅CDH 5 Packaging and Tarball信息。以下示例显示了如何从CDH 5.2 / Hive 0.13.1升级:
$ schematool -dbType mysql -passWord <db_user_pswd> -upgradeSchemaFrom
0.13.1 -userName <db_user_name>
Metastore connection URL:
jdbc:mysql://<cluster_address>:3306/<user_name>?useUnicode=true&characterEncoding=UTF-8
Metastore Connection Driver : com.mysql.jdbc.Driver
Metastore connection User: <user_name>
Starting upgrade metastore schema from version 0.13.1 to <new_version>
Upgrade script upgrade-0.13.1-to-<new_version>.mysql.sql
Completed pre-0-upgrade-0.13.1-to-<new_version>.mysql.sql
Completed upgrade-0.13.1-to-<new_version>.mysql.sql
schemaTool completed
- 使用 -validate 选项来验证Metastore schema。以下示例显示schematool 与此选项一起使用时对Metastore模式执行的验证类型:
$ schematool -dbType mysql -passWord <db_user_pswd> -userName
<db_user_name> -validate
Starting metastore validation
Validating schema version
Succeeded in schema version validation.
[SUCCESS]
Validating sequence number for SEQUENCE_TABLE
Succeeded in sequence number validation for SEQUENCE_TABLE
[SUCCESS]
Validating metastore schema tables
Succeeded in schema table validation.
[SUCCESS]
Validating database/table/partition locations
Succeeded in database/table/partition location validation
[SUCCESS]
Validating columns for incorrect NULL values
Succeeded in column validation for incorrect NULL values
[SUCCESS]
Done with metastore validation: [SUCCESS]
schemaTool completed
- 如果您想查找schema升级所需的所有脚本,请使用 dryRun 选项。
$ schematool -dbType mysql -upgradeSchemaFrom 0.10.0 -dryRun -passWord
<db_user_pswd> -userName <db_user_name>
Metastore connection URL:
jdbc:mysql://<cluster_address>:3306/<user_name>?useUnicode=true&characterEncoding=UTF-8
Metastore Connection Driver : com.mysql.jdbc.Driver
Metastore connection User: <user_name>
Starting upgrade metastore schema from version 0.10.0 to <new_version>
Upgrade script upgrade-0.10.0-to-0.11.0.mysql.sql
Upgrade script upgrade-0.11.0-to-0.12.0.mysql.sql
Upgrade script upgrade-0.12.0-to-0.13.0.mysql.sql
Upgrade script upgrade-0.13.0-to-0.14.0.mysql.sql
Upgrade script upgrade-0.14.0-to-1.1.0.mysql.sql
Upgrade script upgrade-1.1.0-to-<new_version>.mysql.sql
schemaTool completed