Application Scenarios
SmartQoS dynamically allocates storage resources to ensure performance for critical services and high-priority subscribers.
Ensuring Performance of Critical Services
SmartQoS allows you to configure different performance goals for various services, ensuring the performance of critical services.
To ensure the performance of critical services, you can:
- Set I/O priorities.
- Create a SmartQoS traffic control policy.
For example, a storage system processes Online transaction processing (OLTP) and backup services, where:
- OLTP services are critical and time-sensitive.
- Backup services have a large data amount and are tolerant of latency.
Table 1-2 lists the I/O characteristics of those two services.
Application |
I/O Characteristic |
Peak Hours of Operation |
|---|---|---|
OLTP |
Random small I/Os, typically measured in IOPS |
08:00 to 00:00 |
Backup |
Sequential large I/Os, typically measured in bandwidth |
00:00 to 08:00 |
Sufficient system resources must be reserved for the two services in their specific periods.
- You can adjust I/O priorities to prioritize OLTP services.
- Set the I/O priority of OLTP services to high, ensuring the performance of OLTP services.
- Set the I/O priority of backup services to low, preventing backup services from contending resources with OLTP services.
- You can use the following two methods:
- Create two policies for limiting the upper limit.
- Traffic control policy A: limits the bandwidth for archiving backup services (for example, ≤ 50 MB/s) from 08:00 to 00:00 to reserve sufficient system resources for OLTP services and ensure that the OLTP services work normally in the daylight.
- Traffic control policy B: limits the IOPS of OLTP (for example, ≤ 200) from 00:00 to 08:00 to reserve sufficient system resources for archiving backup services at night.
- Create a policy for limiting the lower limit.
Traffic control policy C: limits the latency of OLTP services (for example, ≤ 10 ms) from 08:00 to 00:00 to reserve sufficient system resources for key OLTP services and ensure that the OLTP services work normally in the daylight.
- Create two policies for limiting the upper limit.
Figure 1-3 illustrates how SmartQoS controls storage resources for OLTP and backup services.
Ensuring Performance for High-Priority Subscribers
To reduce the total cost of ownership (TCO), some subscribers run services on the storage platforms offered by a storage service provider instead of dedicated storage systems. However, services of different types and characteristics contend for storage resources. High-priority storage service subscribers may fail to obtain desired resources.
With SmartQoS, providers can alleviate this competition by creating SmartQoS policies and setting I/O priority for subscribers, offering sufficient resources for high-priority subscribers.
For example, a storage service provider offers resources to subscriber A and subscriber B. Table 1-3 lists the characteristics of subscriber A and subscriber B.
Subscriber |
Quality Requirement |
|---|---|
Subscriber A (gold subscriber) |
High |
Subscriber B (silver subscriber) |
Low |
The provider can:
- Adjust I/O priorities to prioritize the services of high-priority subscribers.
- Set the I/O priority of subscriber A to high, ensuring its service performance.
- Set the I/O priority of subscriber B to low, preventing its services from contending with subscriber A for resources.
- Create separate traffic control policies for the two subscribers.
- Traffic control policy A: limits the bandwidth of subscriber A (for example, ≤ 100 MB/s) to ensure service performance of subscriber A without affecting service performance of the storage system.
- Traffic control policy B: limits the bandwidth of subscriber B (for example, ≤ 30 MB/s). This bandwidth is lower than that of subscriber A, to reserve enough system resources for other subscribers.
Figure 1-4 illustrates how SmartQoS controls storage resources for subscriber A and subscriber B.
