To ensure maximum scheduling accuracy for the workload
management dispatcher, the DB2® database
manager attempts to assign realtime priorities to the db2wlmt timer
thread and the db2wlmtm scheduling threads. For
assignment of such priorities to succeed, certain permissions need
to be granted to the DB2 database
manager, depending on the operating system.
Procedure
Without the ability to assign realtime priorities
to the timer and scheduling threads, the DB2 workload
management dispatcher is still able to prioritize work, but not as
accurately or optimally as it would otherwise. The following tasks,
to ensure maximum scheduling accuracy for the workload management
dispatcher, are listed according to operating system. Select the operating
system that pertains to you and then follow the given instructions.
- On AIX® operating
systems, the instance owner must have CAP_NUMA_ATTACH and CAP_PROPAGATE
capabilities to set a higher relative priority for agents. To grant
these capabilities, logon as root and run the following
command:
chuser capabilities=CAP_NUMA_ATTACH,CAP_PROPAGATE
- On Solaris 10 or higher,
the instance owner must have the proc_priocntl privilege
to set a higher relative priority for agents. To grant this privilege,
logon as root and run the following command:
usermod -K defaultpriv=basic,proc_priocntl db2user
In
this example, proc_priocntl is added to the default
privilege set of user db2user.
Moreover, when
the DB2 database manager is
running in a non-global zone of Solaris, the
proc_priocntl privilege
must be added to the limit privilege set of the zone. To grant this
privilege to the zone, logon as
root and run the
following command:
global# zonecfg -z db2zone
zonecfg:db2zone> set limitpriv="default,proc_priocntl"
In
this example, proc_priocntl is added to the limit
privilege set of the zone db2zone.
- On Solaris 9, there is no facility for the DB2 database manager to raise the relative priority
of threads. Upgrade to Solaris 10 or higher to take advantage of this
feature.