发现一个AIX5.2上oracle9I RAC 环境出现大量会话等待“FREE GLOBAL TRANSACTION TABLE ENTRY”

后来经metalink上咨询，后发现，是网络参数没有设过的原因。

需要按照安装文档中所述，修改网络参数

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2.4.3 Configure Network Tuning Parameters

Verify that the network tuning parameters shown in the following table are set to the values shown or higher values. The procedure following the table describes how to verify and set the values.

Network Tuning Parameter	Recommended Value
ipqmaxlen	512
rfc1323	1
sb_max	2*655360
tcp_recvspace	65536
tcp_sendspace	65536
udp_recvspace	655360 Note: The recommended value of this parameter is 10 times the value of the udp_sendspace parameter. The value must be less than the value of the sb_max parameter.
udp_sendspace	65536 Note: This value is suitable for a default database installation. For production databases, the minimum value for this parameter is 4 KB plus the value of the database DB_BLOCK_SIZE initialization parameter multiplied by the value of the DB_MULTIBLOCK_READ_COUNT initialization parameter: (DB_BLOCK_SIZE * DB_MULTIBLOCK_READ_COUNT) + 4 KB

To view the current value specified for these parameters, and to change them if necessary:

1. To check the current values of the network tuning parameters, enter commands similar to the following:

   # /usr/sbin/no -a | more
   
   

2. If you must change the value of any parameter, then enter the following command to determine whether the system is running in compatibility mode:

   # /usr/sbin/lsattr -E -l sys0 -a pre520tune
   
   

   If the system is running in compatibility mode, then the output is similar to the following, showing that the value of the pre520tune attribute is enable:

   pre520tune enable Pre-520 tuning compatibility mode True
   
   

3. If the system is running in compatibility mode, then follow these steps to change the parameter values:

   1. Enter commands similar to the following to change the value of each parameter:

      # /usr/sbin/no -o parameter_name=value
      
      

      For example:

      # /usr/sbin/no -o udp_recvspace=655360
      
      

   2. Add entries similar to the following to the /etc/rc.net file for each parameter that you changed in the previous step:

      if [ -f /usr/sbin/no ] ; then
         /usr/sbin/no -o udp_sendspace=65536
         /usr/sbin/no -o udp_recvspace=655360
         /usr/sbin/no -o tcp_sendspace=65536
         /usr/sbin/no -o tcp_recvspace=65536
         /usr/sbin/no -o rfc1323=1
         /usr/sbin/no -o sb_max=2*655360
         /usr/sbin/no -o ipqmaxlen=512
      fi
      
      

      By adding these lines to the /etc/rc.net file, the values persist when the system restarts.

4. If the system is not running in compatibility mode, then enter commands similar to the following to change the parameter values:

   • ipqmaxlen parameter:

     /usr/sbin/no -r -o ipqmaxlen=512
     
     

   • Other parameter:

     /usr/sbin/no -p -o parameter=value