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ViewsTriggering multiple lambda functions from one SQS trigger
I'm not sure if I understand AWS Lambda - SQS triggers correctly. Can I possibly configure it in such a way that one SQS queue can trigger different lambda functions depending on the message body or a message attribute?
My use case: I have three different lambda functions (processCricket, processFootball, processTennis) each of which perform a unique function. I have a single queue (processGame) which receives messages. Each message on the queue has a attribute "type" which is either "Cricket", "Football" or "Tennis". Can I invoke a different lambda function depending on the "type" on the message?
Option 1: Configure SQS to trigger a different lambda function depending on the type (Not sure if I can do this)
Option 2: Configure one lambda function which can check type and then call the other lambda functions depending on its type
Option 3: Create separate queues for each lambda. Control which lambda processes the message by adding the message to the appropriate queue.
3 answers
Answer question0
Option 1: Configure SQS to trigger a different lambda function depending on the type
You can't know about the type until it is consumed by the lambda. So this one is not possible.
Option 2: Configure one lambda function which can check type and then call the other lambda functions depending on its type
Yes it is the "possible" way of first option. but it may cost "more" depending on your usage. When you consume the sqs in batch mode, then you have to invoke multiple lambdas by making multiple checks.
Option 3: Create separate queues for each lambda. Control which lambda processes the message by adding the message to the appropriate queue.
In my opinion, this could be the best option. You can configure different DLQ for each queue, set different batch size depending on your business rules, no need for extra lambda to increase "complexity".
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You should not configure multiple Lambda functions as triggers for a single SQS queue. This is because the message in SQS will be delivered to any one consumer and while this message is being processed by that consumer, it would not be visible to others. Thus, you wouldn't be able to decide which "type" of message goes to which function, so Option 1 is invalid.
Both Option 2 and 3 should work fine. I would select Option 2 if you do not expect that many messages to be delivered to your queue, thus not having to worry about Lambda scaling. Also note, multiple messages can be delivered in a single batch to the Lambda trigger, so you would have to implement your logic accordingly.
If you're expecting a large number of messages, then Option 3 would be better suited.
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Your best option here would be to not send the messages directly to the queue at all. You can use either SNS or EventBridge as the destination for the message. Then you should have one queue for each type of message. You can then subscribe each queue to the source (SNS or EventBridge) and only receive the messages that make sense for that queue. With EventBridge you can do a fair amount of filtering on the entire payload. For SNS you'd need to add the type to the attributes so it can be used for filtering.
