Governor rule clauses

In partitioned database environments, a local application snapshot is used to collect information for setlimit evaluation, instead of a global snapshot. The forcecoord action occurs only if setlimit values are exceeded on the application's coordinating partition. For example, if a rule has a setlimit of "idle 30" and a coordinating agent has been idle for 40 seconds the forcecoord action will terminate the application on all partitions. However, if a remote subagent has been idle for 40 seconds, no action will be performed.

• On Linux and UNIX-based systems, the agentpri database manager configuration parameter must be set to the default value; otherwise, it overrides the nice value.
• On Windows platforms, the agentpri database manager configuration parameter and the nice value can be used together.

You can use the governor to control the priority of applications that run in the default user service superclass, SYSDEFAULTUSERCLASS. If you use the governor to lower the priority of an application that runs in this service superclass, the agent disassociates itself from its outbound correlator (if it is associated with one) and sets its relative priority according to the agent priority specified by the governor. You cannot use the governor to alter the priority of agents in user-defined service superclasses and subclasses. Instead, you must use the agent priority setting for the service superclass or subclass to control applications that run in these service classes. You can, however, use the governor to force connections in any service class.

   chuser capabilities=CAP_NUMA_ATTACH,CAP_PROPAGATE <userid>

usermod -K defaultpriv=basic,proc_priocntl db2user

global# zonecfg -z db2zone
zonecfg:db2zone> set limitpriv="default,proc_priocntl"

On Solaris 9, there is no facility for DB2 to raise the relative priority of agents. Upgrade to Solaris 10 or higher to use the ACTION NICE clause of DB2 governor.

The top three applications in each criterion are given higher priorities than all other applications. That is, the top application in each criterion group is given the highest priority, the next highest application is given the second highest priority, and the third-highest application is given the third highest priority. If a single application is ranked in the top three for more than one criterion, it is given the appropriate priority for the criterion in which it ranked highest, and the next highest application is given the next highest priority for the other criteria. For example, if application A holds the most locks but has the third shortest estimated remaining run time, it is given the highest priority for the first criterion. The fourth ranked application with the shortest estimated remaining run time is given the third highest priority for that criterion.

The applications that are selected by this governor rule are divided up into three classes. For each class, the governor chooses nine applications, which are the top three applications from each class, based on the criteria described above. If you specify the class option, all applications that are selected by this rule are considered to be a single class, and nine applications are chosen and given higher priorities as described above.

If an application is selected in more than one governor rule, it is governed by the last rule in which is it selected.

• Ensure that applications in different groups get time, without all applications splitting time evenly. For example, if 14 applications (three short, five medium, and six long) are running at the same time, they might all have poor response times because they are splitting the CPU. The database administrator can set up two groups, medium-length applications and long-length applications. Using priorities, the governor permits all the short applications to run, and ensures that at most three medium and three long applications run simultaneously. To achieve this, the governor configuration file contains one rule for medium-length applications, and another rule for long applications.
  The following example shows a portion of a governor configuration file that illustrates this point:

  desc "Group together medium applications in 1 schedule class."
  applname medq1, medq2, medq3, medq4, medq5
  setlimit cpu -1
  action schedule class;
  
  desc "Group together long applications in 1 schedule class."
  applname longq1, longq2, longq3, longq4, longq5, longq6
  setlimit cpu -1
  action schedule class;

• Ensure that each of several user groups (for example, organizational departments) gets equal prioritization. If one group is running a large number of applications, the administrator can ensure that other groups are still able to obtain reasonable response times for their applications. For example, in a case involving three departments (Finance, Inventory, and Planning), all the Finance users could be put into one group, all the Inventory users could be put into a second group, and all the Planning users could be put into a third group. The processing power would be split more or less evenly among the three departments.
  The following example shows a portion of a governor configuration file that illustrates this point:

  desc "Group together Finance department users."
  authid tom, dick, harry, mo, larry, curly
  setlimit cpu -1
  action schedule class;
  
  desc "Group together Inventory department users."
  authid pat, chris, jack, jill
  setlimit cpu -1
  action schedule class;
  
  desc "Group together Planning department users."
  authid tara, dianne, henrietta, maureen, linda, candy
  setlimit cpu -1
  action schedule class;

• Let the governor schedule all applications.

  If the class option is not specified, the governor creates its own classes based on how many active applications fall under the schedule action, and puts applications into different classes based on the query compiler's cost estimate for the query the application is running. The administrator can choose to have all applications scheduled by not qualifying which applications are chosen; that is, by not specifying applname, authid, or setlimit clauses.