1.今天遇到一个错误，在连接到hive之后，无法执行任何命令。
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$ beeline -u "jdbc:hive2://hostname.domain.cn:10000/default;principal=hive/_HOST@domain.com;" Connecting to jdbc:hive2://hostname.domain.cn:10000/default;principal=hive/_HOST@domain.com; Connected to: Apache Hive (version release-1.2.1-EDH-1.1.2) Driver: Hive JDBC (version release-1.2.1-EDH-1.1.2) Transaction isolation: TRANSACTION_REPEATABLE_READ Beeline version release-1.2.1-EDH-1.1.2 by Apache Hive 0: jdbc:hive2://hostname.domain.cn:10000> show databases;
返回错误如下
Error: Error while processing statement: 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.) (state=08S01,code=1)
2. 百度这个错误，很多文档都提及是字符集的问题，需要保证MySQL的字符集是latin1.
mysql> show variables like '%collation_%'; +----------------------+-------------------+ | Variable_name | Value | +----------------------+-------------------+ | collation_connection | latin1_swedish_ci | | collation_database | latin1_swedish_ci | | collation_server | latin1_swedish_ci | +----------------------+-------------------+
3. 如果字符集不是latin1，需要手动执行(本次问题，不是这个，我的字符集，原本就是latin1)
mysql>use hive mysql>alter database hive character set latin1;
4. 后来尝试重启一下hive，结果，metastore竟然启动失败。查看日志，说创建表失败。这个hive已经运行一段时间了，一直没有问题。对应的表也都是存在的，没有道理重建的。
5.日志输出如下：
Traceback (most recent call last): File "/var/lib/ambari-agent/cache/common-services/HIVE/0.12.0.2.0/package/scripts/hive_metastore.py", line 259, inHiveMetastore().execute() File "/usr/lib/python2.6/site-packages/resource_management/libraries/script/script.py", line 280, in execute method(env) File "/var/lib/ambari-agent/cache/common-services/HIVE/0.12.0.2.0/package/scripts/hive_metastore.py", line 59, in start self.configure(env) File "/var/lib/ambari-agent/cache/common-services/HIVE/0.12.0.2.0/package/scripts/hive_metastore.py", line 73, in configure hive(name = 'metastore') File "/usr/lib/python2.6/site-packages/ambari_commons/os_family_impl.py", line 89, in thunk return fn(*args, **kwargs) File "/var/lib/ambari-agent/cache/common-services/HIVE/0.12.0.2.0/package/scripts/hive.py", line 320, in hive user = params.hive_user File "/usr/lib/python2.6/site-packages/resource_management/core/base.py", line 155, in __init__ self.env.run() File "/usr/lib/python2.6/site-packages/resource_management/core/environment.py", line 160, in run self.run_action(resource, action) File "/usr/lib/python2.6/site-packages/resource_management/core/environment.py", line 124, in run_action provider_action() File "/usr/lib/python2.6/site-packages/resource_management/core/providers/system.py", line 273, in action_run tries=self.resource.tries, try_sleep=self.resource.try_sleep) File "/usr/lib/python2.6/site-packages/resource_management/core/shell.py", line 71, in inner result = function(command, **kwargs) File "/usr/lib/python2.6/site-packages/resource_management/core/shell.py", line 93, in checked_call tries=tries, try_sleep=try_sleep) File "/usr/lib/python2.6/site-packages/resource_management/core/shell.py", line 141, in _call_wrapper result = _call(command, **kwargs_copy) File "/usr/lib/python2.6/site-packages/resource_management/core/shell.py", line 294, in _call raise Fail(err_msg) resource_management.core.exceptions.Fail: Execution of 'export HIVE_CONF_DIR=/usr/hdp/current/hive-metastore/conf/conf.server ; /usr/hdp/current/hive-metastore/bin/schematool -initSchema -dbType mysql -userName hive -passWord [PROTECTED] -verbose' returned 1. Metastore connection URL: jdbc:mysql://hostname.mysql.cn/hivemeta Metastore Connection Driver : com.mysql.jdbc.Driver Metastore connection User: hive Starting metastore schema initialization to 1.2.0 Initialization script hive-schema-1.2.0.mysql.sql Connecting to jdbc:mysql://hostname.mysql.cn/hivemeta Connected to: MySQL (version 5.1.73) Driver: MySQL Connector Java (version mysql-connector-java-5.1.40 ( Revision: 402933ef52cad9aa82624e80acbea46e3a701ce6 )) Transaction isolation: TRANSACTION_READ_COMMITTED 0: jdbc:mysql://hostname.mysql.cn/hivem> !autocommit on Autocommit status: true 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40101 SET @OLD_CHARACTER_SET_C LIENT=@@CHARACTER_SET_CLIENT */ No rows affected (0.003 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40101 SET @OLD_CHARACTER_SET_R ESULTS=@@CHARACTER_SET_RESULTS */ No rows affected (0 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40101 SET @OLD_COLLATION_CONNE CTION=@@COLLATION_CONNECTION */ No rows affected (0 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40101 SET NAMES utf8 */ No rows affected (0 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40103 SET @OLD_TIME_ZONE=@@TIM E_ZONE */ No rows affected (0.002 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40103 SET TIME_ZONE='+00:00' * / No rows affected (0 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40014 SET @OLD_UNIQUE_CHECKS=@ @UNIQUE_CHECKS, UNIQUE_CHECKS=0 */ No rows affected (0 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40014 SET @OLD_FOREIGN_KEY_CHE CKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */ No rows affected (0.001 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40101 SET @OLD_SQL_MODE=@@SQL_ MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */ No rows affected (0 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40111 SET @OLD_SQL_NOTES=@@SQL _NOTES, SQL_NOTES=0 */ No rows affected (0.001 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40101 SET @saved_cs_client = @@character_set_client */ No rows affected (0 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> /*!40101 SET character_set_client = utf8 */ No rows affected (0.001 seconds) 0: jdbc:mysql://hostname.mysql.cn/hivem> CREATE TABLE IF NOT EXISTS `BUCKE TING_COLS` ( `SD_ID` bigint(20) NOT NULL, `BUCKET_COL_NAME` varchar(256) CHARACT ER SET latin1 COLLATE latin1_bin DEFAULT NULL, `INTEGER_IDX` int(11) NOT NULL, P RIMARY KEY (`SD_ID`,`INTEGER_IDX`), KEY `BUCKETING_COLS_N49` (`SD_ID`), CONSTRAI NT `BUCKETING_COLS_FK1` FOREIGN KEY (`SD_ID`) REFERENCES `SDS` (`SD_ID`) ) ENGIN E=InnoDB DEFAULT CHARSET=latin1 Error: Can't create table 'hivemeta.bucketing_cols' (errno: 121) (state=HY000,code=1005) Closing: 0: jdbc:mysql://hostname.mysql.cn/hivemeta org.apache.hadoop.hive.metastore.HiveMetaException: Schema initialization FAILED! Metastore state would be inconsistent !! org.apache.hadoop.hive.metastore.HiveMetaException: Schema initialization FAILED! Metastore state would be inconsistent !! at org.apache.hive.beeline.HiveSchemaTool.doInit(HiveSchemaTool.java:270) at org.apache.hive.beeline.HiveSchemaTool.doInit(HiveSchemaTool.java:243) at org.apache.hive.beeline.HiveSchemaTool.main(HiveSchemaTool.java:473) 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.util.RunJar.run(RunJar.java:221) at org.apache.hadoop.util.RunJar.main(RunJar.java:136) Caused by: java.io.IOException: Schema script failed, errorcode 2 at org.apache.hive.beeline.HiveSchemaTool.runBeeLine(HiveSchemaTool.java:358) at org.apache.hive.beeline.HiveSchemaTool.runBeeLine(HiveSchemaTool.java:326) at org.apache.hive.beeline.HiveSchemaTool.doInit(HiveSchemaTool.java:266) ... 8 more *** schemaTool failed ***
6.根据关键字“Schema initialization FAILED! Metastore state would be inconsistent !!”，查询到hdp的官方论坛。
解释说，这个是一个已知的问题。需要修改ambari的sql脚本，删除mysql的一些index等。
https://community.hortonworks.com/questions/113748/hive-metastore-start.html
7. 官方建议的步骤繁多。个人比较懒。而且这个hive库，前一天还是正常的。这个问题是突然出现的，我不倾向与，这个是bug的可能。
继续分析，查看hivemetastore的log，还是有必要的。
发现问题，表不存在
2018-03-07 15:34:43,871 INFO [pool-8-thread-200]: metastore.HiveMetaStore (HiveMetaStore.java:logInfo(746)) - 200: get_all_databases 2018-03-07 15:34:43,871 INFO [pool-8-thread-200]: HiveMetaStore.audit (HiveMetaStore.java:logAuditEvent(371)) - ugi=ambari-qa-hbjt_hadoop@domain.com ip=/172.18.98.57 cmd=get_all_databases 2018-03-07 15:34:43,873 ERROR [pool-8-thread-200]: metastore.RetryingHMSHandler (RetryingHMSHandler.java:invoke(165)) - HMSHandler Fatal error: javax.jdo.JDOException: Exception thrown when executing query at org.datanucleus.api.jdo.NucleusJDOHelper.getJDOExceptionForNucleusException(NucleusJDOHelper.java:596) ...... NestedThrowablesStackTrace: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Table 'hivemeta.dbs' doesn't exist at sun.reflect.GeneratedConstructorAccessor60.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
8.现在要从mysql入手分析，逐步检查。
mysql> use hive mysql> show tables; +---------------------------+ | Tables_in_hivemeta | +---------------------------+ | BUCKETING_COLS | | CDS | | COLUMNS_V2 | | COMPACTION_QUEUE | | COMPLETED_TXN_COMPONENTS | | DATABASE_PARAMS | | DBS | | DB_PRIVS | | DELEGATION_TOKENS |
9. 问题来了，表不存在。为什么不存在呢？其实我已经知道问题了。Mysql表名大小写敏感问题。
mysql>select count(*) from `DBS`; ERROR 1146 (42S02): Table 'hivemeta.DBS' doesn't exist
10. 由于很多Oracle数据库的表名是大小写不敏感的。但是Mysql却是表名大小写敏感的。所以，很多开发人员，都喜欢将mysql设置为表名大小写不敏感。
而show tables之后，我就怀疑这个可能了。
11. 经过检查/etc/my.cnf，确实已经设置lower_case_table_names=1
12. Hive库创建的时候，mysql是大小写敏感的。所以，表名都是大写的。而后期，有人修改了mysql参数，取消大小写敏感。这样，问题就来了。Mysql并不是完全不敏感，而是在设置参数lower_case_table_names=1 之后，创建和查询的sql语句中的表名，默认修改为小写的。而已经创建的表名，还是大写的显示。但是你无论用大写表名，还是小写表名，都无法正确查询到了。
13. 这个问题出现的场景：
只有是在hive库创建完成之后，又修改/etc/my.cnf，添加参数lower_case_table_names=1导致的。
14. 问题找到之后，有两个解决方案：
a. 取消参数lower_case_table_names=1
b. 如果mysql的hive库中没有什么数据，删除hive库表，重新创建hive meta表，直接就创建出小写的表名了。
输出就是小写的了：
mysql> show tables; +---------------------------+ | Tables_in_hive_beta | +---------------------------+ | bucketing_cols | | cds | | columns_v2 | | compaction_queue | | completed_txn_components | | database_params | | db_privs | | dbs | | delegation_tokens | | func_ru |
15. 我最后选择取消参数lower_case_table_names=1，并重启mysql。查询正常了。
mysql> select count(*) from `DBS`; +----------+ | count(*) | +----------+ | 2 |
16. Ambari启动hive metastore也成功了。
问题解决，一切恢复正常
$ beeline -u "jdbc:hive2://hostname.domain.cn:10000/default;principal=hive/_HOST@domain.com;" Connecting to jdbc:hive2://hostname.domain.cn:10000/default;principal=hive/_HOST@domain.com; Connected to: Apache Hive (version release-1.2.1-EDH-1.1.2) Driver: Hive JDBC (version release-1.2.1-EDH-1.1.2) Transaction isolation: TRANSACTION_REPEATABLE_READ Beeline version release-1.2.1-EDH-1.1.2 by Apache Hive 0: jdbc:hive2://hostname.domain.cn:10000> show databases; +----------------+--+ | database_name | +----------------+--+ | default | | hbjt | +----------------+--+ 2 rows selected (1.206 seconds)
最终的原因，就是有人修改的/etc/my.cnf，导致的本次问题。
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