Docs: improve documention regarding the change to async when migrating from BatchProcessorSync to BatchProcessor #4760
Description
Expected Behavior
Migrating from BatchProcessorSync and processPartialResponseSync to BatchProcessor and processPartialResponse with the processInParallel flag set to false should make no change to behaviour.
Current Behavior
Using BatchProcessor and processPartialResponse with the processInParallel flag set to false processes records in parallel, which means we lose data where before we didn't.
Code snippet
const processor = new BatchProcessor(EventType.SQS);
const recordHandler =
(qtyMap: Record<string, number>) => (record: SQSRecord) => {
const { product } = extractDataFromEnvelope(
record,
'powertools_json(body)',
);
const productCode = product.code;
const items = product.items;
for (const item of items) {
const id = item.itemId;
const qty = Math.ceil(item.quantity);
if (!qtyMap[id]) {
qtyMap[id]= [
qty,
];
} else {
qtyMap[id]?.push(
qty,
);
}
}
};
const handler = (event: SQSEvent) => processPartialResponse(
event,
recordHandler(elementQuantityMap),
processor,
{ processInParallel: false }
);Steps to Reproduce
With some records that have a list of item IDs and quantities, you can run the above and see that records get overwritten because they're being process in parallel still, even when specified not to.
e.g.
{
"product": { "id": "1" "items": [{
itemId: 'sku1',
quantity: 1.00000000,
},
{
itemId: 'sku2',
quantity: 1.08300000,
},
{
itemId: 'sku3',
quantity: 5.00000000,
},
{
itemId: 'sku4',
quantity: 4.00000000,
},] }
{
"product": { "id": "2" "items": [{
itemId: 'sku1',
quantity: 1.00000000,
},
{
itemId: 'sku2',
quantity: 1.08300000,
},
{
itemId: 'sku3',
quantity: 5.00000000,
},
{
itemId: 'sku4',
quantity: 4.00000000,
},] }I'd expect a map like;
{
"sku1": [1, 1],
"sku2: [2, 2]
... etc
}But instead I just get something like;
{
"sku1" : [1],
"sku2: [2]
... etc, some keys even misisng
}Possible Solution
No response
Powertools for AWS Lambda (TypeScript) version
latest
AWS Lambda function runtime
22.x
Packaging format used
Lambda Layers