SET UTIL_IMPACT_PRIORITY command
The SET UTIL_IMPACT_PRIORITY command changes the impact setting for a running utility.
- Throttle a utility that was invoked in unthrottled mode
- Unthrottle a throttled utility (disable throttling)
- Reprioritize a throttled utility (useful if running multiple simultaneous throttled utilities)
Scope
Authorization
One of the following authorities:
- SYSADM
- SYSCTRL
- SYSMAINT
- SYSMON
Required connection
ID = 2
Type = BACKUP
Database Name = IWZ
Partition Number = 1
Description = online db
Start Time = 07/19/2007 17:32:09.622395
State = Executing
Invocation Type = User
Throttling:
Priority = Unthrottled
Progress Monitoring:
Estimated Percentage Complete = 10
Total Work = 97867649689 bytes
Completed Work = 10124388481 bytes
The
instance attachment must be made to partition 1 in order to issue a SET
UTIL_IMPACT_PRIORITY command against the utility with ID 2. To do this, set
DB2NODE=1
in the environment and then issue the instance attachment command.Command syntax
Command parameters
- utility-id
- ID of the utility whose impact setting will be updated. IDs of running utilities can be obtained with the LIST UTILITIES command.
- TO priority
- Specifies an instance-level limit on the impact associated with running a utility. A value of 100 represents the highest priority and 1 represents the lowest priority. Setting priority to 0 will force a throttled utility to continue unthrottled. Setting priority to a non-zero value will force an unthrottled utility to continue in throttled mode.
Examples
SET UTIL_IMPACT_PRIORITY FOR 2 TO 0
SET UTIL_IMPACT_PRIORITY FOR 3 TO 10
Relationship between UTIL_IMPACT_LIM and UTIL_IMPACT_PRIORITY settings
The database manager configuration parameter util_impact_lim sets the limit on the impact throttled utilities can have on the overall workload of the machine. 0-99 is a throttled percentage, 100 is no throttling.
The SET UTIL_IMPACT_PRIORITY command sets the priority that a particular utility has over the resources available to throttled utilities as defined by the util_impact_lim configuration parameter. (0 = unthrottled)
- Backup with util_impact_priority 70
- Runstats with util_impact_priority 50
Both utilities combined should have no more than a 10% average impact on the total workload, and the utility with the higher priority will get more of the available workload resources. For both the backup and RUNSTATS operations, it is also possible to declare the impact priority within the command line of that utility. If you do not issue the SET UTIL_IMPACT_PRIORITY command, the utility will run unthrottled (irrespective of the setting of util_impact_lim).
To view the current priority setting for the utilities that are running, you can use the LIST UTILITIES command.
Usage notes
Throttling requires having an impact policy defined by setting the util_impact_lim configuration parameter.