比ORA-24777: 不允许使用不可移植的数据库链路更让人郁闷的事情

现场有一个同步功能报错，内容如下：

java.sql.BatchUpdateException: ORA-24777: 不允许使用不可移植的数据库链路

at oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:10317)

at oracle.jdbc.driver.OracleStatementWrapper.executeBatch(OracleStatementWrapper.java:216)

at weblogic.jdbc.wrapper.PreparedStatement.executeBatch(PreparedStatement.java:210)

   1.了解了一下功能，大致如下：

有A、B两个数据库，在A数据库上建了一个dblink，在XA的JDBC驱动下，通过dblink就会出现这种错误。

   2.此错误有些生僻，直接查metalink见附录。两种解决方案供选择：

a. Configure the database to allow the use of shared servers

ALTER SYSTEM SET DISPATCHERS="(PROTOCOL=TCP)" scope=both;

ALTER SYSTEM SET SHARED_SERVERS = 10 scope=both;

b. Define the database link being utilised as a shared database link

CREATE SHARED DATABASE LINK dblink_name

[CONNECT TO username IDENTIFIED BY password]|[CONNECT TO CURRENT_USER]

AUTHENTICATED BY schema_name IDENTIFIED BY password

[USING ‘service_name‘];

   3.现场调整

先用a方案在B数据库上调整了，用b方案在A数据库上做了调整，测试不行。再用a方案在A数据库上调整了，测试还是不行。

   4.到现场发现问题

发现同义词不对，就是没有用到这个shared的dblink，艹，这太让人郁闷了，调了半天，没有用到。

我认为的结论是：只要把A库中的dblink改为shared的方式就可以了。

Using Database Links in Oracle XA Applications

Oracle XA applications can access other Oracle Database instances through database links with these restrictions:

• They must use the shared server configuration.

  The transaction processing monitors (TPMs) use shared servers to open the connection to an Oracle Database A. Then the operating system network connection required for the database link is opened by the dispatcher instead of a dedicated server process. This
  allows different services or threads to operate on the transaction.

  If this restriction is not satisfied, then when you use database links within an XA transaction, it creates an operating system network connection between the dedicated server process and the other Oracle Database B. Because this network connection cannot be
  moved from one dedicated server process to another, you cannot detach from this dedicated server process of database A. Then when you access the database B through a database link, you receive an ORA-24777 error.

• The other database being accessed must be another Oracle Database.

If these restrictions are satisfied, Oracle Database allows such links and propagates the transaction protocol (prepare, rollback, and commit) to the other Oracle Database instances.

If using the shared server configuration is not possible, then access the remote database through the Pro*C/C++ application by using EXECSQL AT syntax.

The init.ora parameter OPEN_LINKS_PER_INSTANCE specifies
the number of open database link connections that can be migrated. Thesedblink connections
are used by XA transactions so that the connections are cached after a transaction is committed. Another transaction can use the database link connection if the user who created the connection also created the transaction. This parameter is different from
the init.ora parameter OPEN_LINKS,
which specifies the maximum number of concurrent open connections (including database links) to remote databases in one session. The OPEN_LINKS parameter
does not apply to XA applications.

ORA-24777 reported when using a database link from within an XA coordinated transaction (文档 ID 1506756.1)

转到底部