Skip to content

Latest commit

 

History

History
68 lines (48 loc) · 3.15 KB

README.md

File metadata and controls

68 lines (48 loc) · 3.15 KB

Kinesis Analytics Example

This example uses a Kinesis Analytics application that invokes a Lambda when it sees records with a low lux value. This Lambda then sends a message to SNS, which is (by default) hooked up to your email address.

Getting Started

There's a CloudFormation script that will create the Kinesis application (but see below for caveats). It has the following parameters:

  • BaseName
    This is a name used to prefix all resources created by the stack.

  • LuxThreshold
    The lux level that will trigger a notification.

  • SourceStream
    The name of a Kinesis stream containing temperature readings. Defaults to the stream created for this workshop.

  • DestinationEmail
    An email address that will receive notifications. This has no default; you'll need to enter your email address.

Running

When CloudFormation creates a Kinesis Analytics application, it is in the "Ready" state. To start it, you have to go to the AWS Console, select the application, and choose the "Start Application" action.

Next, verify that the application is receiving data:

  1. Open the application by clicking on its name and then clicking the "Application Details" button.
  2. Click on the "Go to SQL results" button.
  3. It will take 20-30 seconds, but you will see a sampling of rows from your source data.

Then, trigger some output:

  1. Click on the "Real-time Analytics" tag. After 20-30 seconds you'll see an empty data table, and the message that no rows have arrived yet.
  2. Hold your finger over the light sensor for 20-30 seconds, and you should see results that show a lux value under the threshold.
  3. Open the CloudWatch Logs group for your Lambda function, and verify that messages have been written to the logs. If you don't see this, you will need to re-create the destination (see "gotcha" below).
  4. Verify that you've received an email.

Caveats and Gotchas

SNS requires you to confirm that you want to receive notifications. Once you create your stack, you'll receive an email with a confirmation link. Click that link or you won't see any notifications.

The name of a Kinesis Analytics stream is limited ot 32 characters. Since we create stream names based on the "base name" provided as a CloudFormation parameter, a long name will cause stack creation failure.

We have seen cases where the application as created by CloudFormation does not send results to Lambda. Disconnecting the destination and then reconnecting after the application has been started appears to solve this issue.

We have also seen the case where data continues to be sent long after the application has been deleted. This is primarily an issue when you're doing development, and re-creating the same application.