Using HP PRM with Oracle Databases

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HP Process Resource Manager and Oracle integration
summary
The approaches for using PRM with Oracle are summarized in the following two sections. These
approaches are:
• Partial resource isolation—Isolating CPU and private memory resources only when the system is at
peak load but allowing CPU and private memory resources to be shared when the system is not at
peak load
• Total resource isolation—Complete isolation of both the CPU and the private memory resources
With either form of isolation, you can also specify a minimum amount of per-group shared memory.
If you plan on using the Oracle Database Resource Manager, you must use total resource isolation.
As explained in previous sections, the Database Resource Manager and PRM must agree on the
amount of CPU and memory resources available.
Partial resource isolation
Partial resource isolation means that the Oracle database instances are assigned to FSS PRM groups
and are all executing within a given set of cores. The CPU cycles and private memory used by one
database instance can be loaned out to database instances running in other FSS PRM groups when
the database instance is lightly loaded. Likewise, when the Oracle database instance is heavily
loaded, it can borrow CPU cycles and private memory from other FSS PRM groups that are not under
stress. On HP-UX 11i v2 and later, you can dedicate a minimum amount of shared memory to an FSS
PRM group. This memory can be assigned on a group-by-group basis. On HP-UX 11i v3 and later,
you can set an upper bound for CPU resource consumption by an FSS PRM group on a group-by-
group basis.
Advantages
The advantages of partial resource isolation are:
• More efficient use of CPU and private memory resources because not all Oracle database instances
are likely to be under heavy load constantly. Any easing of load on one of the database instances
allows other instances to grab those resources.
• Significantly improved performance for the heavily stressed database instance when one or more of
the other instances are lightly loaded. This advantage results from the FSS PRM group of the heavily
stressed instance borrowing resources from the other FSS PRM groups containing lightly loaded
database instances.
• A fraction of a core can be allocated to a FSS PRM group for more fine-grained tuning.
Disadvantages
The disadvantages of partial resource isolation are:
• The Oracle Database Resource Manager is not supported.
• Less deterministic behavior because the amounts of CPU and private memory resources are
dependent on the loads on the other database instances. These loads on other database instances
can vary significantly and are unpredictable.