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Alternative to Amazon DynamoDB Time to Live (TTL)


  • Certain data lose relevance after a specified time.
  • So create records in datastore that should exists only for a specified time from the creation time.
  • Time can be anything from 1 second to hours.

Example Case: Make the record expire within 10 seconds of its creation time.

Option 1: Application based timer (Not Recommended)
Whenever Application creates a record it has to trigger a timer as shown below JavaScript example timer:

setTimeout's not the right way to keep track of timer... Let's assume it works for explaining this option.
setTimeout(function() {
}, 10000);
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Problem: An Application receiving thousands of request per second has to create those number of timers. This option is not scalable.

Option 2: Amazon DynamoDB - (Not Recommended)
DynamoDB per-partition scanner background process automatically and continuously evaluates the expiry status of items in the table.

Amazon DynamoDB TTL typically deletes expired items within 48 hours of expiration. Scan & Filter by timestamp not a scalable option.
This option works best if your TTL is minimum 48 hours.
Not matching with our scenario of expiring items in 10 seconds.

Option 3: Amazon Elasticache (Recommended)
Redis compatible Amazon Elasticache honours TTL by seconds.
Code example:

redis_client.set('key', 'value', {
  EX: 10
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Matches with our 10 seconds expiring scenario.

Please let me know your thoughts or other options in comments.

Image by Sadia from Pixabay

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