5.2.3.3 Using Allocation-Based Resource Management
In IORM, an allocation value specifies the resource allocation as a percentage (0-100).
With allocation-based resource management, each allocation is associated with a level. Valid level values are from 1 to 8, and the sum of allocation values cannot exceed 100 for each level. Resources are allocated to level 1 first, and then remaining resources are allocated to level 2, and so on.
Though not recommended, allocation-based resource management
can be used in the interdatabase plan (dbplan
). For
the category plan (catplan
), allocation-based
resource management is the only option.
The following example illustrates how to use allocation-based resource management in an interdatabase plan. Consider four databases sharing the same Oracle Exadata Storage Server resources. The four databases are:
- A critical OLTP production database, named
PROD
- A test database, named
PROD_TEST
- A development database, named
PROD_DEV
- A data warehouse database, named
DW
An OLTP production database typically issues small I/O
requests, and low latency for these requests is the critical
requirement. A data warehouse issues large numbers of large I/O
requests and is more sensitive to the I/O throughput than the
latency of each individual I/O request. Without any I/O resource
management, the large number of I/O requests issued by the
DW
database could overwhelm the storage
subsystem and increase the latency of the I/O requests issued by the
PROD
database. Additionally, the I/O
requests issued by the test and development databases,
PROD_TEST
and PROD_DEV
,
could adversely affect the performance of the PROD
and the DW
databases.
To ensure a reasonable distribution of I/O resources, you can define an allocation-based interdatabase plan as follows:
CellCLI> ALTER IORMPLAN -
dbPlan=((name=prod, level=1,allocation=80), -
(name=dw, level=2, allocation=80), -
(name=prod_test, level=3, allocation=50), -
(name=prod_dev, level=3, allocation=40), -
(name=OTHER, level=3, allocation=10))
By using the example interdatabase plan:
- The critical OLTP database (
PROD
) is guaranteed 80 percent of the I/O resources during periods of I/O resource contention. - The
DW
database gets 80 percent any remaining unused I/O. - Finally, the
PROD_TEST
andPROD_DEV
databases get any unused I/O in the amount of 50 percent and 40 percent respectively. Also, in this example, a 10% allocation is reserved forOTHER
databases that are not explicitly listed in the plan.
At any time, you change the allocations to adjust the resource assignments.
Parent topic: Administering the IORM Plan