Spot Fleet is an AWS service that enables you to launch and manage a collection of Spot Instances and optionally On-Demand Instances to meet your target capacity requirements. This powerful feature helps SysOps Administrators optimize costs while maintaining application performance and availability…Spot Fleet is an AWS service that enables you to launch and manage a collection of Spot Instances and optionally On-Demand Instances to meet your target capacity requirements. This powerful feature helps SysOps Administrators optimize costs while maintaining application performance and availability.
Spot Fleet works by allowing you to define a target capacity and specify multiple instance types, Availability Zones, and launch specifications. The service then automatically requests Spot Instances from the most cost-effective pools based on your configuration. This diversification strategy helps ensure capacity availability and reduces the impact of Spot Instance interruptions.
Key components of Spot Fleet include:
1. **Launch Templates/Configurations**: Define instance specifications including AMI, instance types, security groups, and other parameters.
2. **Allocation Strategies**: Choose from strategies like lowest-price (selects cheapest pools), diversified (spreads across pools), capacity-optimized (selects pools with highest availability), or price-capacity-optimized (balances price and capacity).
3. **Target Capacity**: Specify desired capacity in terms of instances, vCPUs, or memory units.
4. **Instance Weighting**: Assign weights to different instance types based on their capacity contribution to your workload.
For cost optimization, Spot Fleet can reduce compute costs by up to 90% compared to On-Demand pricing. SysOps Administrators can set maximum price limits and configure the fleet to maintain target capacity by replacing interrupted instances.
Spot Fleet also supports integration with Auto Scaling to dynamically adjust capacity based on demand. You can configure instance replacement behavior and set up CloudWatch alarms for monitoring fleet health and performance.
Best practices include using multiple instance types and Availability Zones, implementing proper interruption handling in applications, and combining Spot Instances with On-Demand Instances for baseline capacity. This hybrid approach ensures application reliability while maximizing cost savings for variable workloads.
Spot Fleet: Complete Guide for AWS SysOps Administrator Associate
Why Spot Fleet is Important
Spot Fleet is a critical concept for AWS cost optimization, allowing you to save up to 90% compared to On-Demand pricing. As a SysOps Administrator, understanding Spot Fleet enables you to design cost-effective, scalable architectures while maintaining application availability. This topic frequently appears in exam questions related to cost optimization and compute resource management.
What is Spot Fleet?
Spot Fleet is a collection of Spot Instances and optionally On-Demand Instances that AWS launches based on your specifications. It attempts to maintain the target capacity you specify by automatically requesting Spot Instances to meet your desired capacity at the lowest possible price.
Key components of Spot Fleet include: - Launch Specifications: Define instance types, AMIs, subnets, and other launch parameters - Target Capacity: The number of instances or vCPUs you want to maintain - Allocation Strategy: How instances are selected from available pools
How Spot Fleet Works
1. Request Submission: You submit a Spot Fleet request specifying your target capacity, maximum price, launch specifications, and allocation strategy.
2. Instance Selection: Spot Fleet evaluates available capacity pools based on your allocation strategy and launches instances to meet your target capacity.
3. Capacity Maintenance: If Spot Instances are interrupted, Spot Fleet automatically attempts to replace them to maintain your target capacity.
Allocation Strategies: - lowestPrice: Launches instances from the pools with the lowest price (default) - diversified: Distributes instances across all specified pools for better availability - capacityOptimized: Launches instances from pools with optimal capacity, reducing interruption likelihood - capacityOptimizedPrioritized: Similar to capacityOptimized but considers your priority order
Request Types: - Request: One-time request that does not maintain target capacity after interruptions - Maintain: Continuously maintains target capacity by replacing interrupted instances
How to Answer Exam Questions on Spot Fleet
Step 1: Identify the Scenario Type Determine if the question focuses on cost optimization, availability, or fault tolerance.
Step 2: Analyze Requirements Look for keywords like flexible workloads, stateless applications, batch processing, or big data analytics.
Tip 1: When a question mentions maintaining a specific number of instances at the lowest cost, think Spot Fleet with the maintain request type.
Tip 2: For workloads requiring high availability with Spot Instances, the diversified allocation strategy spreads instances across multiple pools.
Tip 3: Questions about reducing Spot Instance interruptions should point you toward capacityOptimized allocation strategy.
Tip 4: Remember that Spot Fleet can combine both Spot and On-Demand Instances in a single fleet for a balanced approach.
Tip 5: If a scenario involves time-sensitive batch jobs, Spot Fleet with multiple instance types and Availability Zones provides the best chance of obtaining capacity.
Tip 6: Spot Fleet integrates with Auto Scaling groups through EC2 Fleet, which may appear in scaling-related questions.
Tip 7: Know that Spot Fleet requests can specify a maximum price per instance type or use the default On-Demand price as the ceiling.
Common Exam Scenarios: - Stateless web applications needing cost reduction → Spot Fleet with diversified strategy - Big data processing with flexible timing → Spot Fleet with lowestPrice strategy - CI/CD pipelines with variable demand → Spot Fleet with capacityOptimized strategy - Mixed workloads requiring baseline capacity → Spot Fleet combining On-Demand and Spot Instances