Lab 004 - jazzwang/hive_labs GitHub Wiki

實作四

Sqoop (4) : 將 MySQL 資料表匯入 Hive

建立 Hive 資料表

  1. 首先，請刪除 Sqoop (2) 產生的 HDFS 目錄 mysql_data
user@master ~ $ hadoop fs -rmr mysql_data

否則，等一下執行 sqoop create-hive-table 或 sqoop import 時，會出現以下的訊息。

13/12/22 14:14:55 INFO hive.HiveImport: Hive import complete.
13/12/22 14:14:55 INFO hive.HiveImport: Export directory is not empty, keeping it.
  1. 請輸入如下指令並將「帳號」處替換成您的帳號：
user@master ~ $ export DBID=帳號
user@master ~ $ sqoop create-hive-table --connect "jdbc:mysql://sql.3du.me/$DBID" --table MSSQL_DATA --username $DBID -P
Enter password: 輸入密碼
  1. 若資料表 Schema 轉換有正常執行，您將看到以下的類似訊息：
13/12/22 13:44:43 INFO tool.BaseSqoopTool: Using Hive-specific delimiters for output. You can override
13/12/22 13:44:43 INFO tool.BaseSqoopTool: delimiters with --fields-terminated-by, etc.
13/12/22 13:44:43 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.
13/12/22 13:44:44 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `mysql_data` AS t LIMIT 1
13/12/22 13:44:44 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `mysql_data` AS t LIMIT 1
.. 略 ..
  1. 檢查 Hive 的 HDFS 目錄是否有產生資料表
user@master ~ $ hadoop fs -ls /hive/warehouse
Found 3 items
drwx------   - jazz supergroup          0 2013-12-17 00:24 /hive/warehouse/dummy
drwx------   - user supergroup          0 2013-12-22 13:20 /hive/warehouse/mssql_data
drwx------   - user supergroup          0 2013-12-22 12:25 /hive/warehouse/mysql_data
  1. 檢查 Hive mysql_data 資料表是否有內容
user@master ~ $ hadoop fs -ls /hive/warehouse/mysql_data

執行記錄匯入

  1. 請輸入如下指令(與前面不同的是加上 --hive-import --hive-table mysql_data 參數)
user@master ~ $ export DBID=帳號
user@master ~ $ sqoop import --connect "jdbc:mysql://sql.3du.me/$DBID" --table mysql_data --username $DBID -P --hive-import --hive-table mysql_data
Enter password: 輸入密碼
  1. 若資料表匯入有正常執行，您將看到以下的類似訊息：
13/12/22 13:51:58 INFO tool.BaseSqoopTool: Using Hive-specific delimiters for output. You can override
13/12/22 13:51:58 INFO tool.BaseSqoopTool: delimiters with --fields-terminated-by, etc.
13/12/22 13:51:58 INFO manager.MySQLManager: Preparing to use a MySQL streaming resultset.
13/12/22 13:51:58 INFO tool.CodeGenTool: Beginning code generation
13/12/22 13:51:58 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `mysql_data` AS t LIMIT 1
13/12/22 13:51:58 INFO manager.SqlManager: Executing SQL statement: SELECT t.* FROM `mysql_data` AS t LIMIT 1
... 略 ...
13/12/22 13:54:59 INFO hive.HiveImport: OK
13/12/22 13:54:59 INFO hive.HiveImport: Time taken: 5.73 seconds
13/12/22 13:55:00 INFO hive.HiveImport: Loading data to table default.mysql_data
13/12/22 13:55:00 INFO hive.HiveImport: OK
13/12/22 13:55:00 INFO hive.HiveImport: Time taken: 1.693 seconds
13/12/22 13:55:00 INFO hive.HiveImport: Hive import complete.

檢查匯入結果

  1. 轉換之結果，可於 Hive 儲存於 HDFS 的路徑查到。
user@master ~ $ hadoop fs -ls /hive/warehouse/mysql_data
Found 2 items
-rw-------   3 user user          0 2013-12-22 13:54 /hive/warehouse/mysql_data/_SUCCESS
-rw-------   3 user user         16 2013-12-22 13:54 /hive/warehouse/mysql_data/part-m-00000
  1. 檢視 part-m-***** 轉換結果
user@master ~ $ hadoop fs -cat /hive/warehouse/mysql_data/part-m-00000
No encryption was performed by peer.
13/12/22 14:00:36 INFO util.NativeCodeLoader: Loaded the native-hadoop library
1Hello
2World

參考資料

  1. "Sqoop: Big data conduit between NoSQL and RDBMS", Surajit Paul, Advisory Consultant, IBM, 23 Jul 2013
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