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/DynamoDB Atomic Counters/

DynamoDB Atomic Counters

0

Greetings!

I have an application that utilizes a DynamoDB table to manage counters. When we update the value of the counter, we consume the returned value - this returned value is the old value of the counter. This counter is then used to retrieve a value in an array, it is effectively an index.

I currently increment these counters with Lambda functions - it's highly likely that many Lambdas may attempt to update the value of a given counter at the same time. It's important that each Lambda function receives a different value of the counter.

Utilizing DynamoDB atomic counters, can I expect that each Lambda function will receive a different value for the counter?

Example:

  • 10 Lambdas attempt to update value of a counter where its current value is 0
  • The Update Expression is "ADD count :incr" where ":incr" is 1
  • Each Lambdas update is processed
  • The returned value from each update is unique per Lambda and the values are 0 - 9
  • The final value of the counter is 10
1 Answers
2

Yes, this is exactly how atomic counters work. You can find more info here

EXPERT
answered 14 days ago
EXPERT
reviewed 14 days ago

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