Wondering how to set up Time to Live (TTL) in DynamoDB? we can help you.

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Today, let us see how we can perform this.

How to set up Time to Live (TTL) in DynamoDB?

Amazon DynamoDB TTL allows you to define a per-item timestamp to determine when an item is no longer necessary.

After the expiration of the TTL timestamp, DynamoDB deletes the item from your table within 48 hours without consuming any write throughput.

The time taken to delete the items might vary depending on the size and activity level of your table.

Today, let us see the steps followed by our Support Techs for set up.

Enable Time to Live (Console)

Follow these steps to enable Time to Live using the DynamoDB console:

1. Firstly, sign in to the AWS Management Console and open the DynamoDB console at https://console.aws.amazon.com/dynamodb/.

2. Choose Tables, and then choose the table that you want to modify.

3. Then in Table details, next to TTL attribute, choose Manage TTL.

4. In the Manage TTL dialog box, choose Enable TTL, and then enter the TTL attribute name.

There are three settings in Manage TTL:

Enable TTL – Choose this to either enable or disable TTL on the table. It can take up to one hour for the change to fully process.

TTL Attribute – The name of the DynamoDB attribute to store the TTL timestamp for items.

24-hour backup streams – Choose this setting to enable Amazon DynamoDB Streams on the table.

5. To preview some of the items that will be deleted when TTL is enabled, choose Run preview.

Warning

This provides you with a sample list of items. It does not provide you with a complete list of items that will be deleted by TTL.

6. Choose Continue to save the settings and enable TTL.

Now that TTL is enabled, the TTL attribute is marked TTL when you view items on the DynamoDB console.

You can view the date and time that an item expires by hovering your pointer over the attribute.

Enable Time to Live (AWS CLI)

1. Firstly, enable TTL on the TTLExample table.

aws dynamodb update-time-to-live --table-name TTLExample --time-to-live-specification "Enabled=true, AttributeName=ttl"

2. Then, describe TTL on the TTLExample table.

aws dynamodb describe-time-to-live --table-name TTLExample
{
"TimeToLiveDescription": {
"AttributeName": "ttl",
"TimeToLiveStatus": "ENABLED"
}
}

3. Finally, add an item to the TTLExample table with the Time to Live attribute set using the BASH shell and the AWS CLI.

EXP=`date -d ‘+5 days’ +%s`
aws dynamodb put-item –table-name “TTLExample” –item ‘{“id”: {“N”: “1”}, “ttl”: {“N”: “‘$EXP'”}}’

When you create a TTL attribute in a table, keep the following in mind:

• TTL attributes must use the Number data type. Other data types, such as String, aren’t supported.
• TTL attributes must use the epoch time format. For example, the epoch timestamp for October 28, 2019 13:12:03 UTC is 1572268323.
• You can use a free online converter, such as EpochConverter, to get the correct value.

[Stuck with the procedures? We’d be happy to assist]

Conclusion

In short, we saw how our Support Techs set up Time to Live (TTL) in DynamoDB.