This topic explains the I/O Resource Management (IORM) feature and how to
enable it, modify the IORM settings, and disable it by using the Console or the API.
About IORM The I/O Resource Management (IORM) feature allows you to manage how multiple databases share the I/O resources of an Oracle Exadata cloud VM cluster for systems using the new resource model or DB system
The I/O Resource Management (IORM) feature allows you to manage how multiple
databases share the I/O resources of an Oracle Exadata cloud VM cluster for systems using
the new resource model or DB system
On an Exadata VM cluster or DB system, all databases share dedicated storage servers which include flash storage. By default, the databases are given equal priority with respect to these resources. The Exadata storage management software uses a first come, first served approach for query processing. If a database executes a major query that overloads I/O resources, overall system performance can be slowed down.
IORM allows you to assign priorities to your databases to ensure critical queries are processed first when workloads exceed their resource allocations. You assign priorities by creating directives that specify the number of shares for each database. The number of shares corresponds to a percentage of resources given to that database when I/O resources are stressed.
Directives work together with an overall optimization objective you set for managing the resources. The following objectives are available:
Auto - (Default objective). IORM determines the optimization
objective and continuously and dynamically determines the optimal settings, based on
the workloads observed, and resource plans enabled.
Balanced - For critical OLTP and DSS workloads. This setting balances low
disk latency and high throughput. This setting limits disk utilization of large I/Os
to a lesser extent than low latency to achieve a balance between good latency and
good throughput.
High throughput - For critical DSS workloads that require high throughput.
Low latency - For critical OLTP workloads. This setting provides the lowest possible latency by significantly limiting disk utilization.
Enabling IORM includes specifying an optimization objective and configuring your resource
plan directives.
Open the navigation menu. Click Oracle Database,
then click Oracle Exadata Database Service
on Dedicated Infrastructure
Choose your Compartment.
Click Exadata VM Clusters under the Oracle Exadata Database
Service on Dedicated Infrastructure.
In the list of VM clusters, find the VM cluster for which you want to enable IORM,
and click its highlighted name. The cluster's details are displayed, showing the
IORM status as "Disabled."
Click Enable IORM.
It might take a minute for the Enable I/O Resource Management dialog to retrieve
the VM cluster information.
Select the objective to apply to the resource plan:
Auto - (Default objective) Dynamically
changes the objective based on the resource plan and observed
workloads.
Balanced - Weighs high throughput and low latency evenly.
High throughput - Provides the best throughput for DSS
workloads.
Low latency - Provides the best latency for critical OLTP
workloads.
Configure the resource plan default directive by setting the number of shares. This
number of shares is assigned to each database not associated with a specific
directive.
In the Resource Plan Directives section, add a directive for each database you
want to assign a greater or lesser number of shares than the default
directive.
To add a directive, click + Additional Directive, then specify the
database and the number of shares for that database.
When you are done adding directives, click Enable.
While the IORM configuration settings are being applied, the VM cluster details
page shows the IORM status as "Updating." The update might take
several minutes to complete but should have no impact on your ability to perform
normal operations on your VM cluster. After a successful update, the IORM status
shows as "Enabled."
Use this procedure to change your IORM settings or to disable IORM.
Open the navigation menu. Click Oracle Database,
then click Oracle Exadata Database Service
on Dedicated Infrastructure
Choose your Compartment.
Click Exadata VM Clusters under Oracle Exadata Database
Service on Dedicated Infrastructure.
In the list of VM clusters, find the VM cluster for which you want to update IORM,
and click its highlighted name. The cluster's details are displayed, showing the
IORM status as "Enabled."
Click Update IORM.
In the Update I/O Resource Management dialog, take one of the following
actions:
Change your settings - Specify a new objective and adjust your directives,
as applicable, and then click Update.
Disable IORM - Click Disable IORM.
Disabling IORM removes all your resource plan directives and restores
the Auto (default) objective for I/O resource management.
While the new IORM configuration settings are being applied, the system details
page shows the IORM status as "Updating." The update might take
several minutes to complete but should have no impact on your ability to perform
normal operations on your DB system. After a successful update, the IORM status
shows as "Enabled" or "Disabled," depending on the action
you took.
This topic only applies to Exadata Cloud Infrastructure instances using the DB system resource model.
Enabling IORM includes specifying an optimization objective and configuring your resource plan directives.
Open the navigation menu. Click Oracle Database,
then click Oracle Exadata Database Service
on Dedicated Infrastructure
Choose your Compartment.
In the list of DB systems, find the Exadata DB system for which you want to enable IORM, and click its highlighted name.
The system details are displayed, showing the IORM status as "Disabled."
Click Enable IORM.
It might take a minute for the Enable I/O Resource Management dialog to retrieve the DB system information.
Select the objective to apply to the resource plan:
Auto - (Recommended) Dynamically changes the objective based on the resource plan and observed workloads.
Balanced - Weighs high throughput and low latency evenly.
High throughput - Provides the best throughput for DSS workloads.
Low latency - Provides the best latency for critical OLTP workloads.
Configure the resource plan default directive by setting the number of shares. This number of shares is assigned to each database not associated with a specific directive.
In the Resource Plan Directives section, add a directive for each database you want to assign a greater or lesser number of shares than the default directive.
To add a directive, click + Additional Directive, then specify the database and the number of shares for that database.
When you are done adding directives, click Enable.
While the IORM configuration settings are being applied, the system details page shows the IORM status as "Updating." The update might take several minutes to complete but should have no impact on your ability to perform normal operations on your DB system. After a successful update, the IORM status shows as "Enabled."
To modify the IORM configuration on your
Exadata DB system π
Use this procedure to change your IORM settings or to disable
IORM.
Note
This topic only applies to Exadata Cloud Infrastructure instances using the DB
system resource model.
Open the navigation menu. Click Oracle Database, then click Bare Metal,
VM, and Exadata.
Choose your Compartment.
In the list of DB systems, find the Exadata DB system for which you want to
modify the IORM configuration, and click its highlighted name.
The system details are displayed, showing the IORM status as "Enabled."
Click Update IORM.
In the Update I/O Resource Management dialog, take one of the following
actions:
Change your settings - Specify a new objective and adjust your directives,
as applicable, and then click Update.
Disable IORM - Click Disable IORM.
Disabling IORM removes all your resource plan directives and restores
the Auto (default) objective for I/O resource management.
While the new IORM configuration settings are being applied, the system details
page shows the IORM status as "Updating." The update might take several minutes
to complete but should have no impact on your ability to perform normal
operations on your DB system. After a successful update, the IORM status shows
as "Enabled" or "Disabled," depending on the action you took.
Use these API operations to manage the I/O resources of an Exadata cloud VM
cluster. (see The New Exadata Cloud Service Resource
Model for more information on this resource type).