Lambda   AWS

AWS Lambda

 · 1 min read

AWS Lambda

Lambda is serverless, e.g. run code without provising or managing servers.

Usage patterns

  • Execute code in response to triggers such as changes in data, changes in system state, or actions by users
  • Real-time File Processing and stream
  • Process AWS Events
  • Replace Cron
  • ETL

Cost

  • Charged by the number of requests to functions and code execution time
  • $0.20 per 1 million requests
  • Code execution $0.00001667 for every GB-second used

Performance

  • Process events within milliseconds
  • Latency higher for cold-start

  • Retain a function instance and reuse it to serve subsequent requests, versus creating new copy

  • Uses replication and redundancy for high availability of the service and the functions it operates

Durability and availability

  • No maintenance windows or scheduled downtime
  • On failure, Lambda synchronoously responds with an exception
  • Asynchronous functions are retried at least 3 times

Scalability and elasticity

  • Scales automatically with no limits with dynamic capacity allocation

Interfaces

  • Trigger Lambda from AWS servies events
  • Respond to CloudTrail audit log entries as events

Anti-patterns

  • Long running applications: 900 sec runtime
  • Dynamic websites
  • Stateful applications: must be stateless