DB2 9 database distributed management-utility for execution of throttling

The following articles mainly describe the utility for implementing throttling in the Distributed Management of DB2 9 database and the related commands to be used in actual operations, the following is a detailed description of the main content of the article. I hope you will have a better understanding of it after browsing.

DB2 9 utility for execution of Throttling in Distributed Management:

Defining an impact policy does not mean that all utilities are throttled. In fact, by default, utilities run in non-Throttling mode even if an influence policy has been defined. To run a utility in throttling mode, you must enable throttling when calling the utility or enable throttling after starting the utility. Some utilities cannot enable throttling when calling, but can only enable throttling after startup, such as REBALANCE.

To enable throttling when calling a utility, you must specify the UTIL_IMPACT_PRIORITY option in the command used to execute the utility. For example, to call the Backup utility and enable throttling, run the following backup database command:

 
 

  
  
BACKUP DATABASE sample UTIL_IMPACT_PRIORITY 
 
 

Currently, only the backup database and RUNSTATS commands can identify the UTIL_IMPACT_PRIORITY clause. In addition, you must first define the impact policy (by setting the configuration parameter util_impact_lim), and then the UTIL_IMPACT_PRIORITY clause can take effect on these commands.

The UTIL_IMPACT_PRIORITY clause has an optional relative priority parameter (value between 0 and 100; 0 indicates disabled). This parameter is used to distinguish the importance of a throttling utility. Compared with a lower-priority throttling utility, a higher-priority utility consumes more resources. IBM recommends that you accept the default priority value of 50 instead of the relative priority value. (Remember that the cumulative impact of all throttling utilities is still limited by the impact policy .)

Modify Impact Policy

To modify the influence priority (throttling level) of a running utility, run the SET UTIL_IMPACT_PRIORITY command. You can use this command:

The utility started in non-Throttling mode is throttled,

Cancel the throttling for the utility,

Reset the DB2 9 database priority of the throttling utility. (This function can be used if multiple throttling utilities are run at the same time and one of them is important .)

The syntax of the SET UTIL_IMPACT_PRIORITY command is:

 
 

  
  
SET UTIL_IMPACT_PRIORITY [UtilityID] TO [Priority] 
 
 

Where:

UtilityID indicates the running utility whose priority is to be modified with ID.

Priority specifies the instance-level impact limit associated with this utility. 100 indicates the highest priority;

1 indicates the lowest priority. Setting Priority to 0 will enable the utility of throttling to continue running in non-Throttling mode;

Setting Priority to a non-zero value will enable the non-Throttling utility to continue running in the throttling mode.

Therefore, if you want the non-Throttling Backup operation with the utility ID 1 to continue running in the throttling mode, you can run the following SET UTIL_IMPACT_PRIORITY command:

 
 

  
  
SET UTIL_IMPACT_PRIORITY 1 TO 20 
 
 

After this command is executed, the cumulative impact of the Backup operation and other DB2 9 database throttling utilities executed at the same time is lower than the percentage value specified for the configuration parameter util_impact_lim; value 20 defines the importance of Backup operations over other throttling utilities.