CODEWITHSUNDEEP
amazon-web-servicesamazon-s3aws-lambdaamazon-sqs
shinyatk
shinyatk

Reputation: 1065

How to wait to trigger Lambda function until specific files are uploaded

I'm new to AWS and working on Lambda function triggered by S3. I have two json files and need to use the both data to send queue to SQS. For example, two files, "file_a.json" and "file_b.json" are to be uploaded to S3 at the same time.

file_a.json
{"data": "123"}

file_b.json
{"data": "456"}

Then, Lambda will send queue message like ["123", "456"] which is created with the data from both files.

However, S3 invokes Lambda function every time the single file is uploaded and this makes it hard to send queue to SQS as I wrote above. I'm thinking if S3 can wait until the two files are uploaded to trigger Lambda, it can solve the issue. If anyone had faced the similar situation, I would like to know how to resolve this problem. Thanks!

Upvotes: 0

Views: 700

Answers (1)

MisterSmith
MisterSmith

Reputation: 3624

S3 notifications are simple events in response to changes in S3, so you cant "make s3 wait" for both files, its upto you to handle that in your lambda.

You could store the message (or whatever data you need) - s3, rds, paramstore etc, or if you can deduce the other filename from the message you can query S3 and check if the other file exists yet and act accordingly.

Upvotes: 3

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