错误信息

应用包运行时收到报错信息如下：

ORA-00600: internal error code, arguments: [4450],[kpotx.c],[2866],[],…
ORA-02063: preceding line from DW_JOB_PROD
line ORA-06512: line at ""APP.PKG_JOB_FAST_NEW"" …

ORA-00600报错一般与Oracle数据库内部Bug有关。注意第一行arguments后面三个方括号中的数字与信息，可用于确定相关的数据库Bug。

Bug信息

在MOS上匹配到相关的Bug信息描述如下：

ORA-00600 [4450] can occur when using autonomous transactions andmultiple database links if the value for open_links was too small.If you get ORA-00600[4450] at the remote side of a database link, it may be
this bug. Check for traces at the local side and find out if more database
links were potentially being used than the configured value for open_links
(the default value is 4).

经确认，报错的应用确实使用了大量DBLINK，与该BUG描述的触发场景一致。

检查open_links当前值：

--当前值为16
SQL> show parameter open_linksNAME				     TYPE	 VALUE
------------------------------------ ----------- ------------------------------
open_links			     integer	 16
open_links_per_instance 	     integer	 16

应对办法

官方推荐了两种应对办法。一种是workaround办法，另一种是升级数据库到版本12.2.0.1。

Workaround:
Increase the value for open_links.Bug 22114696 - ORA-600 [4450], [kpotx.c], [2866] (Doc ID 22114696.8)

问题数据库版本为11g，没有升级到12c的计划。因此这里我们采用workaround，即调大open_links，将其调大到100。该参数调整后需要重启数据库。

调整open_links参数：

sys@ORA11G> alter system set open_links=100 scope=both;
alter system set open_links=100 scope=both*
ERROR at line 1:
ORA-02095: specified initialization parameter cannot be modifiedsys@ORA11G> alter system set open_links=100 scope=spfile;
System altered.sys@ORA11G> shutdown immediate;
sys@ORA11G> startup;

🐟OPEN_LINKS参数含义

• OPEN_LINKS specifies the maximum number of concurrent open connections to remote databases in one session.
• These connections include database links, as well as external procedures and cartridges, each of which uses a separate process.