報錯

使用連線測試命令：

sqoop list-databases --connect jdbc:mysql://master:3306/ --username bee -P

報如下錯誤：

18/12/02 20:11:44 ERROR manager.CatalogQueryManager: Failed to list databases
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
	at com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:174)
	at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:64)
	at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835)
	at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:455)
	at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
	at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:207)
	at java.sql.DriverManager.getConnection(DriverManager.java:664)
	at java.sql.DriverManager.getConnection(DriverManager.java:247)
	at org.apache.sqoop.manager.SqlManager.makeConnection(SqlManager.java:904)
	at org.apache.sqoop.manager.GenericJdbcManager.getConnection(GenericJdbcManager.java:59)
	at org.apache.sqoop.manager.CatalogQueryManager.listDatabases(CatalogQueryManager.java:57)
	at org.apache.sqoop.tool.ListDatabasesTool.run(ListDatabasesTool.java:49)
	at org.apache.sqoop.Sqoop.run(Sqoop.java:147)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
	at org.apache.sqoop.Sqoop.runSqoop(Sqoop.java:183)
	at org.apache.sqoop.Sqoop.runTool(Sqoop.java:234)
	at org.apache.sqoop.Sqoop.runTool(Sqoop.java:243)
	at org.apache.sqoop.Sqoop.main(Sqoop.java:252)
Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure
 

解決辦法

修改 my.cnf 配置檔案：
vim /etc/mysql/my.cnf，如果沒有則新增

[mysqld]
bind-address=0.0.0.0

再次連線成功：