public SNS Topic with a trigger event every quarter hour
Update 2015-10-08: Amazon has released AWS Lambda Scheduled Functions. I recommend using that feature to schedule AWS Lambda functions. In fact, the Unreliable Town Clock switched to use this feature behind the scenes, the day it was announced.
Scheduled executions of AWS Lambda functions on an hourly/daily/etc basis is a frequently requested feature, ever since the day Amazon introduced the service at AWS re:Invent 2014.
Until Amazon releases a reliable, premium cron feature for AWS Lambda, I’m offering a community-built alternative which may be useful for some non-critical applications.
Beyond its event-driven convenience, the primary attraction of AWS Lambda is eliminating the need to maintain infrastructure to run and scale code. The AWS Lambda function code is simply uploaded to AWS and Amazon takes care of providing systems to run on, keeping it available, scaling to meet demand, recovering from infrastructure failures, monitoring, logging, and more.
The available methods to trigger AWS Lambda functions already include some powerful and convenient events like S3 object creation, DynamoDB changes, Kinesis stream processing, and my favorite: the all-purpose SNS Topic subscription.
Even so, there is a glaring need for code that wants to run at regular intervals: time-triggered, recurring, scheduled event support for AWS Lambda. Attempts to to do this yourself generally ends up with having to maintain your own supporting infrastructure, when your original goal was to eliminate the infrastructure worries.
Unreliable Town Clock (UTC)
The Unreliable Town Clock (UTC) is a new, free, public SNS Topic (Amazon Simple Notification Service) that broadcasts a “chime” message every quarter hour to all subscribers. It can send the chimes to AWS Lambda functions, SQS queues, and email addresses.