This topic explains how to select and configure subscription reserved and elastic reserved compute resources using typical scenarios. It provides recommendations to reduce costs and improve efficiency.
Background information
MaxCompute previously supported custom quota chunking and time-based configuration for subscription reserved compute resources. You could divide each day into up to three time periods and assign different quotas to use varying amounts of reserved CUs during those periods. This significantly improved compute resource utilization.
MaxCompute now supports Elastic Reserved CU. Combined with new quota plans and time plans, it enables flexible scaling of compute resources based on usage evaluation. This helps you reduce costs and improve efficiency.
The pricing data in the examples in this topic are for illustration only. The evaluation method is simplified.
Actual prices appear on the product purchase page.
In real business implementations, consider multiple factors and test configurations over time to achieve optimal settings.
Scope of use
You must purchase subscription reserved resources to use Elastic Reserved CU. The maximum Elastic Reserved CU you can configure equals your subscription reserved CU amount. The CU amount must be at least 50 CU and increase in increments of 10 CU.
Elastic Reserved CU uses pay-as-you-go billing by hour and by usage. Billing starts when scaling succeeds and stops when downgrading succeeds. Metering data is pushed hourly on the hour. Hourly bills appear with a 3-hour delay.
Assume the Elastic Reserved CU unit price is USD 0.0488 per CU per hour. The subscription reserved compute resource unit price is USD 22.0 per CU per month.
If you use Elastic Reserved CU for more than 16 hours per day (the cost for 16 hours is
1 CU × USD 0.0488 per CU per hour × 16 hours × 30 days = USD 23.424 per CU per month), purchase subscription reserved CU instead.
Scenario 1: Idle resources
Nighttime is the peak computing period for production projects. Some lines of business have strict timing requirements for data processing—for example, computation results must be ready before a specific time. Daytime computing requests are lower. To meet strong nighttime demand, you purchased MaxCompute subscription reserved resources with a high CU amount. As a result, computing resources remain idle during daytime.
Typical CU usage plan
In this scenario, daily CU usage follows the trend shown in the following figure. You purchase 750 subscription reserved CU to support the 5-hour peak from 03:00 to 08:00.
The original monthly cost is 750 CU × USD 22.0 per CU per month = USD 16,500 per month.
The following figure shows the usage trend of subscription reserved CU:
Elastic Reserved CU plan
Business requirements require guaranteed resources during the midnight peak period and secondary peak periods. You can purchase subscription-based reserved CU capacity of 400 and elastic reserved CU capacity of 350 for 5 hours (03:00–08:00) as computing resources. The following figure shows the usage trend of the combined subscription-based and elastic reserved CU solution:
The monthly cost of the Elastic Reserved CU plan is 400 × USD 22.0 + 350 × USD 0.0488 × 5 × 30 = USD 11,362. Compared to the plan without Elastic Reserved CU, this saves about 31% per month.
Configure Elastic Reserved CU
Log on to the MaxCompute console and select a region in the top-left corner.
In the navigation pane on the left, choose .
Downgrade quota
For MaxCompute subscription resources, follow these steps to downgrade quota.
On the Quotas page, find the target quota and click Downgrade in the Actions column.
On the Downgrade page, configure the desired number of CU, and then click Buy Now to complete the downgrade operation.
For more information about downgrade rules, see and Alibaba Cloud International Website Cancellation Rules.
You can view the details of the downgrade order on the Alibaba Cloud Orders page.
NoteIf you downgrade immediately after an upgrade, you may receive a smaller refund for the following two reasons:
The previous order had a discount. For example, a one-year subscription has a 15% discount. If the original price is 154.7 USD, the actual payment is 131.5 USD. The refund for the downgrade is calculated based on 131.5 USD.
A coupon was used for the previous order. When you downgrade, the refund for the old configuration only includes the cash amount, not the coupon amount.
Add New Configuration Plan
For MaxCompute subscription resources, follow these steps to create a new quota plan. In this example, the level-1 quota's Elastically Reserved CUs is
350.On the Quotas page, find the target quota and click Quota Configuration in the Actions column.
On the Quota Configuration page, click the Scaling Configuration tab.
On the Scaling Configuration tab, click Add Configuration Plan. In the Add Configuration Plan dialog box, enter a Configuration Plan Name and configure Elastically Reserved CUs for the level-1 and level-2 quotas.
Click OK to add the plan.
Edit time plans
Monitor quota resource consumption daily. Perform routine job resource O&M based on actual business needs. Adjust Elastic Reserved CU amounts as needed.
On the Scaling Configuration tab, click Edit Time Plan in the Scheduled Scaling Management area.
Click Add Effective Period and select an Effective Start Time and a Configuration Plan.
Example time plans:
Effective Start Time (UTC+8)
Configuration Plan
00:00
Default
03:00
Quota plan created in the previous step
08:00
Default
The Default plan has
0Elastic Reserved CU.
Scenario 2: Speed-up with low cost and high reliability
You already split your MaxCompute subscription reserved compute resources into level-2 quotas and configured time-based and priority settings. CU usage is high all day. Business teams now require earlier output times for some data to unlock more value.
Typical CU usage plan
The following figure shows daily CU usage in this scenario. You purchased 750 subscription reserved CU. CU usage is high all day, reaching nearly 100%. Job completion times are long. One important dataset used to be ready by 07:00. Now the business team requires it by 06:00. The original monthly cost is 750 CU × USD 22.0 per CU per month = USD 16,500 per month.
The following figure shows the usage trend of subscription reserved CU:
Elastic Reserved CU plan
Resource requests exceed 750 CU from 03:00 to 07:00. To ensure jobs finish by 06:00, scale up during this peak.
Use metadata (Information Schema) to analyze CU usage for jobs related to this dataset. The figure above shows full CU usage from 03:00 to 08:00. So sum CU usage from 03:00 to 07:00 — four hours.
Assume total CU usage over four hours is 2000 CU. That means 500 CU run for four hours. To finish one hour earlier, you need 2000 ÷ 3 = 667 CU per hour. Add a 30% buffer for job dependencies, giving 30% extra: 667 × 1.3 = 867 CU. So you need 867 − 500 = 367 additional CU starting at 03:00.
Elastic Reserved CU increases in increments of 50 CU. Start with 350 CU for three hours. The trend chart is below.
In this case, we predict Elastic Reserved CU needs using ideal average CU usage. In real business use, use this method as a reference. Monitor business conditions and tune as needed.
To ensure this business runs as expected:
Buying 350 subscription reserved CU adds
350 CU × USD 22.0 per CU per month = USD 7,700 per monthto monthly costs.The Elastic Reserved CU plan adds only
350 CU × USD 0.0488 per CU per hour × 3 × 30 = USD 1,537.2to monthly costs.
The Elastic Reserved CU plan saves about 80% per month.
Configure Elastic Reserved CU
These steps assume no prior time-based configuration or that it has been reset.
Log on to the MaxCompute console and select a region in the top-left corner.
In the navigation pane on the left, choose .
Create a Configuration Plan
For MaxCompute subscription resources, follow these steps to create a new quota plan. In this example, the level-1 quota's Elastically Reserved CUs is
350.On the Quotas page, find the target quota and click Quota Configuration in the Actions column.
On the Quota Configuration page, click the Scaling Configuration tab.
On the Scaling Configuration tab, click Add Configuration Plan. In the Add Configuration Plan dialog box, enter a Configuration Plan Name and configure Elastically Reserved CUs for the level-1 and level-2 quotas.
Click OK to add the plan.
Edit time plans
Monitor quota resource consumption daily. Perform routine job resource O&M based on actual business needs. Adjust Elastic Reserved CU amounts as needed.
On the Scaling Configuration tab, click Edit Time Plan in the Scheduled Scaling Management area.
Click Add Effective Period and select an Effective Start Time and a Configuration Plan.
Example time plans:
Effective Start Time (UTC+8)
Configuration Solution Plan
00:00
Default
03:00
Quota plan created in the previous step
06:00
Default
The Default plan has
0Elastic Reserved CU.