Cold Start
A delay in response time when a serverless function is invoked for the first time or after a period of inactivity.
Description
In the context of AWS (Amazon Web Services), a 'Cold Start' occurs when a serverless computing service, such as AWS Lambda, needs to initialize a new instance of a function to handle an incoming request. This happens when the function has not been invoked for a certain period or when the number of concurrent executions exceeds the pre-warmed instances available. During a cold start, the cloud provider must allocate resources, download the function code, and initialize the runtime environment, leading to increased latency for the initial request. This can be particularly impactful in applications with sporadic traffic or those that require rapid, real-time responses, like mobile apps or web APIs. Developers often implement strategies to mitigate cold starts, such as keeping functions warm or using provisioned concurrency to ensure a certain number of instances are always ready to handle requests.
Examples
- An e-commerce website using AWS Lambda to process user authentication may experience a cold start delay when a user logs in after a period of inactivity.
- A data processing pipeline that triggers AWS Lambda functions intermittently can face cold starts, leading to slower data ingestion times.
Additional Information
- Cold starts can lead to latency issues, which may affect user experience, especially in high-performance applications.
- AWS provides options like Provisioned Concurrency to mitigate cold start issues by keeping a specified number of function instances warm at all times.