Auto-tuning: Starting background process GTXj

客户QQ发来信息说有个业务RAC中2节点在一直出现GTXj进程不停的重启，当时一看GTXj进程是什么进程哦

reference一搜发现如下的解释：

GTXn

Global Transaction Process

       These processes help maintain the global information about XA global transactions throughout the cluster. Also, the processes help perform two-phase commit for global transactions anywhere in the cluster so that an Oracle RAC database behaves as a single system to the externally coordinated distributed transactions.

     The GLOBAL_TXN_PROCESSES initialization parameter specifies the number of GTXn processes, where n is 0-9 or a-j. The database automatically tunes the number of these processes based on the workload of XA global transactions. You can disable these processes by setting the parameter to 0. If you try to run XA global transactions with these process disabled, an error is returned.

    GTX进程是由于应用使用XA事务，通过参数GLOBAL_TXN_PROCESSES 来配置默认进程个数，为0时，禁用GTX进程，此时如果应用使用XA事务将会报错，数据库根据XA事务自动的协调进程的个数，如果出现Auto-tuning: Shutting Down Background Process GTX，可以忽略，再看了一个ORACLE无异常的等待事件。这个进程在11G才出现的，并且只有在ORACLE RAC环境才可能会出现。

下面是METALINK相当的文档

Auto-tuning: Shutting Down Background Process GTX [ID 1481153.1]