Where can you change the batch size for an SQS queue that triggers an AWS Lambda function?

Question

I could have sworn that there was an easy way to change the batch size of an SQS queue that is configured as a Lambda trigger, but as of July 2020 I can no longer find where this happens. This may have something to do with the "new SQS console experience" that is currently being advertised on the top of AWS.

I am able to see the current batch size for my queue (screenshot), but the number is not editable. I don't see anything related to batch size in the SQS interface either. It's possible that my current IAM credential does not have the ability to change batch sizes and it's hidden from me. Does anyone know where this value can be changed?

This is hilarious, never noticed this limitation with the new UI! I even tested it on my end and tried to disable it first in hopes that the "Fix" button would let me edit it, but it stayed grayed out...I would suggest for the time being to use AWS CLI to edit the trigger. — Deiv, Jul 28 '20 at 20:31
If you have already added the SQS trigger to lambda, delete and re-add the trigger. You can change the batch size while re-adding the trigger — Vamsi Challa, Feb 04 '22 at 15:47

score 17 · Accepted Answer · answered Jul 28 '20 at 23:29

This limitation would not be related to Amazon SQS console.

It would be related to AWS Lambda, since the Lambda service is responsible for polling the SQS queue and for specifying the batch size to retrieve.

You are correct that there is no function to edit the batch size in the Lambda console.

From update-event-source-mapping — AWS CLI Command Reference, here is an AWS CLI command that can update the batch size:

aws lambda update-event-source-mapping \
    --uuid  "a1b2c3d4-5678-90ab-cdef-11111EXAMPLE" \
    --batch-size 8

Output:

{
    "UUID": "a1b2c3d4-5678-90ab-cdef-11111EXAMPLE",
    "StateTransitionReason": "USER_INITIATED",
    "LastModified": 1569284520.333,
    "BatchSize": 8,
    "State": "Updating",
    "FunctionArn": "arn:aws:lambda:us-west-2:123456789012:function:my-function",
    "EventSourceArn": "arn:aws:sqs:us-west-2:123456789012:mySQSqueue"
}

Or, just delete the trigger in the Lambda console and create a new one.

Thanks! To know the uuid use `aws lambda list-event-source-mappings --function-name ` — Ramesh Murugesan, Sep 28 '21 at 14:25
And if you are using an alias: `aws lambda list-event-source-mappings --function-name :` — lmiguelmh, Oct 08 '21 at 17:39

score 16 · Answer 2 · answered Jul 28 '20 at 23:26

SQS is not an exception. The same goes for DynamoDB and Kinesis streams. I think the reason is that all three services work with lambda through event source mappings. Nothing else is using the mappings.

However, updating event source mappings through console is also not possible. You can use CLI or SDK for that, but this also requires getting UUID of the mapping to modify. Sadly UUID is not provided in console either.

To use in CLI, you have to do it in two steps.

1 Get UUID

aws lambda list-event-source-mappings --query 'EventSourceMappings[].[UUID, EventSourceArn]' --output table

-------------------------------------------------------------------------------------------------------------------------------
|                                                   ListEventSourceMappings                                                   |
+---------------------------------------+-------------------------------------------------------------------------------------+
|  5ab44863-82c2-4acc-b9dc-b14ad368effa |  arn:aws:kinesis:us-east-1:xxxxx:stream/kstream                              |
|  7479947c-bde5-4041-a438-5eb08f350505 |  arn:aws:dynamodb:us-east-1:xxxx:table/test/stream/2020-07-28T23:13:41.006  |
|  40040139-32fb-4297-b094-3f08368c980c |  arn:aws:sqs:us-east-1:xxxxx:Messages                                        |
|  a2b22aa6-f37a-4603-895b-3a044661ebdf |  arn:aws:sqs:us-east-1:xxx:test-queue                                      |
+---------------------------------------+-------------------------------------------------------------------------------------+

2. Update the mapping (e.g. for SQS)

aws lambda update-event-source-mapping --uuid a2b22aa6-f37a-4603-895b-3a044661ebdf --batch-size 5

{
    "UUID": "a2b22aa6-f37a-4603-895b-3a044661ebdf",
    "BatchSize": 5,
    "EventSourceArn": "arn:aws:sqs:us-east-1:xxx:test-queue",
    "FunctionArn": "arn:aws:lambda:us-east-1:xxxx:function:testsfd",
    "LastModified": 1595978738.458,
    "State": "Updating",
    "StateTransitionReason": "USER_INITIATED"
}

Thank you so much! saved my day! – user2608613 Jan 15 '21 at 17:32 — user2608613, Jan 15 '21 at 17:32
@user2608613 No problem. Glad my answer helped:-) – Marcin Jan 15 '21 at 21:49 — Marcin, Jan 15 '21 at 21:49

score 2 · Answer 3 · answered Jan 12 '21 at 01:50

Not sure about before but the lambda UI now does allow you configure the batch size.

Caveat: you have to manually create the trigger from the lamdba UI and not from the SQS UI.

Steps as outlined in the document

Open the Functions page on the Lambda console.
Choose a function.
Under Designer, choose Add trigger.
Choose a trigger type.
Configure the required options and then choose Add.

Configuring a queue as an event source

score 0 · Answer 4 · answered Jun 15 '23 at 21:08

2023 Update

Go to your Lambda function overview (where it shows the diagram with trigger, function, and destination).
Below the diagram, select the Configuration tab.
Select Triggers in the side menu.
Select your trigger from the list.
Click the Edit button from the menu above.
The Trigger configuration menu appears. Here, you can edit the batch size.

Where can you change the batch size for an SQS queue that triggers an AWS Lambda function?

4 Answers4

1 Get UUID

2. Update the mapping (e.g. for SQS)

2023 Update