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Product Billing

Spot Instance Billing

Last updated: 2025-09-11 00:06:36

Overview

Spot Instances are an innovative On-demand billing model that fully utilizes idle computing resources on the cloud platform, providing users with highly competitive pricing advantages. Compared to standard On-demand instances, Spot Instances can deliver the same computing performance at greater discounts, with pricing mechanisms dynamically adjusted based on real-time market supply and demand, improving resource utilization efficiency.

Billing Pricing

Pricing Mechanism
Spot Instances use dynamic discount pricing, with the calculation formula: Spot Instance Price = Same Specification On-demand Instance Price × Discount Factor. Compared to standard On-demand billing, users can save up to approximately 80% in computing costs.

Price Characteristics

  • Different specifications of Spot Instances correspond to different prices and discount factors
  • Prices fluctuate in real-time with market supply and demand, with specific prices displayed in real-time on the cloud server console Spot Instance purchase page
  • Discounts apply only to instance computing resources (vCPU, GPU, memory), while other resource components follow standard On-demand billing rules

Other Resource Billing

  • System disks and data disks: Billed according to standard On-demand billing rules, see Storage Billing
  • Public IP: Billed according to public IP On-demand billing rules, see Network Billing

Billing Cycle

  • Billing Precision: Billed by second to ensure billing accuracy
  • Billing Period: Bills generated hourly for easy cost management

Calculation Examples

Billing Rule Description
Spot Instances use an hourly price statistics mode, where price changes within each hour are billed based on that hour's market price, ensuring billing stability and predictability.

Example 1: Spot Instance Release Due to Market Price Exceeding Bid Price

When Spot Instance inventory is sufficient, if the market price exceeds the user's bid price, the instance will be released. During bill settlement, costs are calculated based on the user's actual usage duration (second-level) and the market price at the time of transaction.

Scenario Description:

  • 8:00 Market price 0.2/hour,userbid0.2/hour,userbid0.7/hour, successfully purchased Spot Instance
  • 9:00 Market price $0.5/hour
  • 10:00 Market price $0.3/hour
  • 11:00 Market price $0.8/hour, exceeds bid price, received instance release notification

Billing Details:
This period includes 3 billing cycles with the following costs:

  • 8:00～9:00: Used 20 minutes, billed at 8:00 market price $0.2/hour
    • Cost: 20 × 60 × (0.2/3600) = $0.0667
  • 9:00～10:00: Used 60 minutes, billed at 9:00 market price $0.5/hour
    • Cost: 60 × 60 × (0.5/3600) = $0.5
  • 10:00～11:00: Used 30 minutes, billed at 10:00 market price $0.3/hour
    • Cost: 30 × 60 × (0.3/3600) = $0.15

Total: Actual usage 1 hour 50 minutes, total approximately $0.717

Example 2: Spot Instance Release Due to Insufficient Inventory

When Spot Instance inventory is insufficient, instances may be released even if the market price is below the user's bid price.

Scenario Description:

  • 8:00 Market price 0.2/hour,userbid0.2/hour,userbid0.7/hour, successfully purchased Spot Instance
  • 9:00 Market price $0.5/hour
  • 10:00 Market price $0.3/hour
  • 11:00 Market price $0.6/hour, although below bid price, due to insufficient inventory, received instance release notification

Billing Details:
Total of 3 billing cycles with the following costs:

  • 8:00～9:00: Used 10 minutes, billed at 8:00 market price $0.2/hour
    • Cost: 10 × 60 × (0.2/3600) = $0.0333
  • 9:00～10:00: Used 60 minutes, billed at 9:00 market price $0.5/hour
    • Cost: 60 × 60 × (0.5/3600) = $0.5
  • 10:00～11:00: Used 48 minutes, billed at 10:00 market price $0.3/hour
    • Cost: 48 × 60 × (0.3/3600) = $0.24

Total: Actual usage 1 hour 58 minutes, total approximately $0.773

Important Notes:

  • Price changes within each billing hour are billed based on the real-time market price statistics for that hour
  • No charges are incurred after instance release
  • All costs are calculated with second-level precision to ensure billing accuracy
  • Users can view current market prices and bid status in real-time on the console