DB2 9 Distributed Management-program throttling and setting and impact policies

This article mainly tells you about the program throttling, setting, and impact policies of DB2 9 Distributed Management, if you are curious about program throttling, setting, and impact policies for the Distributed Management of DB2 9, the following articles will unveil the secrets of the program. I hope you will gain some benefits after browsing.

DB2 9 program-based throttling for Distributed Management

Automatic maintenance activities (backup, statistical data collection, statistical data analysis, and table/index reorganization) consume system resources during operation, thus affecting database performance. In addition, offline database backup and table/index reorganization restrict access to tables, indexes, or the entire database. To minimize the impact on the system, you can use the DB2 adaptive utility throttling system to adjust the resource usage for certain automatic maintenance activities.

Program-based throttling

The adaptive utility throttling system was introduced in DB2 8.1.2. This system enables maintenance utilities to run during a period of high workload while limiting their impact on the system to an acceptable range. This throttling system also enables the utility to automatically obtain more computing resources during off-peak hours, while reducing resource usage during peak hours. In DB2 9.5, the following maintenance operations can take advantage of the adaptive utility throttling system:

Statistical data collection

Backup operation

Data rescheduling

Asynchronous index cleanup

You may have used the utility for throttling, but are not aware of it. By default, DB2 automatically throws some maintenance utilities that are automatically called, such as automatic RUNSTATS.

DB2 9 Distributed Management settings and impact policies

An influence policy must be established to control the utility's throttling. The impact policy refers to the instance range restriction. The influence of all the throttle utilities on the accumulation of productive workloads cannot exceed this restriction. After such a policy is established, the system is responsible for ensuring the implementation of this policy. For all the utilities that enable throttling in an instance, use DB2 Database Manager to configure the util_impact_lim parameter to control their impact policies.

(This parameter is dynamic, so you can modify it without stopping and restarting the instance. You can even set it when the throttling-enabled utility is running .) To define an impact policy for all the throttling utilities, you only need to specify a value between 1 and 100 for the configuration parameter util_impact_lim.

For example, if you want to set the impact of the instance range to 10% (in other words, make sure that the performance impact of all the throttling utilities on the system workload does not exceed 10% ), run the following update database manager Command to set the configuration parameter util_impact_lim to 10:

 
 

  
  
UPDATE DATABASE MANAGER USING UTIL_IMPACT_LIM 10 
 
 

As you might expect, compared with a non-Throttling utility, a throttling utility generally takes longer to complete. If the running time of a utility is too long, you can increase the value of util_impact_lim, or set the configuration parameter util_impact_lim to 100 to completely disable throttling. (If util_impact_lim is set to 100, the utility will not be throttled. In this case, utilities can run as quickly as possible, but they are likely to have a serious impact on workload performance .)