6.1 What Is Oracle Database QoS Management?

Oracle Database QoS Management is an automated, policy-based product that monitors the workload requests for an entire system.

Many companies are consolidating and standardizing their data center computer systems. Instead of using individual servers for each application, they run multiple applications on clustered databases. Also, the migration of applications to the Internet has introduced the problem of managing an open workload. An open workload is subject to demand surges, which can overload a system, resulting in a new type of application failure that cannot be fully anticipated or planned for. To keep applications available and performing within their target service levels in this type of environment, you must:

• Pool resources.

• Have management tools that detect performance bottlenecks in real time.

• Reallocate resources to meet the change in demand.

Oracle Database QoS Management is an automated, policy-based product that monitors the workload requests for an entire system. Oracle Database QoS Management manages the resources that are shared across applications, and adjusts the system configuration to keep the applications running at the performance levels needed by your business. Oracle Database QoS Management responds gracefully to changes in system configuration and demand, thus avoiding additional oscillations in the performance levels of your applications.

Oracle Database QoS Management monitors the performance of each work request on a target system. Oracle Database QoS Management starts to track a work request from the time a work request requests a connection to the database using a database service. The amount of time required to complete a work request, or the response time (also known as the end-to-end response time, or round-trip time), is the time from when the request for data was initiated and when the data request is completed. By accurately measuring the two components of response time, which are the time spent using resources and the time spent waiting to use resources, Oracle Database QoS Management can quickly detect bottlenecks in the system. Oracle Database QoS Management then makes suggestions to reallocate resources to relieve a bottleneck, thus preserving or restoring service levels.

Oracle Database QoS Management manages the resources on your system so that:

• When sufficient resources are available to meet the demand, business-level performance requirements for your applications are met, even if the workload changes.

• When sufficient resources are not available to meet the demand, Oracle Database QoS Management attempts to satisfy performance requirements of more business-critical workloads at the expense of less business-critical workloads.

Starting in Oracle Database release 20c, Oracle Database Quality of Service (QoS) Management automatically configures a default policy set based upon the services it discovers and begins monitoring in measurement mode.

With this implementation, the workload performance data is always available to you and other Oracle Autonomous Health Framework components.

If you do not have Oracle Enterprise Manager deployed to monitor Oracle Database clusters, then you cannot utilize the functionality of Oracle Database QoS Management because you cannot enable it with Enterprise Manager. With automatic monitoring, you can now take advantage of the rich set of workload data provided.

In conjunction with the new REST APIs, you can integrate the advanced Oracle Database QoS Management modes into your management systems. In earlier releases, you have to configure the monitoring functionality of Oracle Database QoS Management and enable Oracle Database QoS Management with Enterprise Manager.

open workload

Work performed in a system in which new work requests to an application come from outside the system being managed. The work requests are independent of each other and the work request arrival rate is not influenced by the response time for previous requests, or the number of requests that have already arrived and are being processed. The number of work requests that the system might be asked to execute at any given time can range from zero to infinity. The system's resources or servers perform various activities to process a work request and the work request leaves the system when processing is complete.

Open workloads are also referred to as request-based workloads.

work request

A work request is the smallest atom of work that a user can initiate. A work request can be an HTTP request, a SOAP request, a SQL statement sent to the database, or the execution of a process. A work request arrives at a layer, perhaps from the outside world, perhaps from another layer. The work request is processed, and a response is generated; the response is sent back to the requester.

end-to-end response time

The expression end-to-end response time includes all time spent and all work done from the time a user request is received (for example, from clicking the Submit button in a browser), until the response is sent back to the user in its entirety. End-to-end response time includes time spent in application servers, Oracle Database, Oracle Automatic Storage Management, and traversing the internal networks of the data center.

bottleneck

A component or resource that limits the performance of an application or an entire system.