floci-io/floci · error · AwsException

InconsistentQuantities

InconsistentQuantities

Error message

The value of Quantity does not match the number of items.

What it means

Floci's CloudFront emulator cross-checks the declared Quantity against the actual number of KeyGroupId items in a TrustedKeyGroups block. If they differ it throws InconsistentQuantities (HTTP 400), the AWS error used for count/item mismatches in list-encoded XML.

Source

Thrown at src/main/java/io/github/hectorvent/floci/services/cloudfront/CloudFrontController.java:2785

            return quantity;
        } catch (NumberFormatException e) {
            throw new AwsException(
                    "InvalidArgument",
                    "TrustedKeyGroups Quantity must be a non-negative integer.",
                    400);
        }
    }

    private static void validateTrustedKeyGroupsQuantity(
            Integer quantity, int itemCount) {
        if (quantity == null) {
            throw new AwsException(
                    "InvalidArgument",
                    "TrustedKeyGroups must include Quantity.",
                    400);
        }
        if (quantity != itemCount) {
            throw new AwsException(
                    "InconsistentQuantities",
                    "The value of Quantity does not match the number of items.",
                    400);
        }
    }

    private static void validateEnabledTrustedKeyGroups(
            boolean enabled, int itemCount) {
        if (enabled && itemCount == 0) {
            throw new AwsException(
                    "InvalidArgument",
                    "TrustedKeyGroups cannot be enabled without a key group.",
                    400);
        }
    }

    private List<String> parseAliases(String body) {
        List<String> result = new ArrayList<>();

View on GitHub (pinned to 62ff490619)

Solutions

Set Quantity to exactly the number of KeyGroupId elements in Items
Derive Quantity programmatically from the list size instead of hardcoding
After editing a config fetched from GET, recount items before resubmitting

Example fix

<!-- before: says 3, lists 2 -->
<Quantity>3</Quantity>
<Items><KeyGroupId>kg-1</KeyGroupId><KeyGroupId>kg-2</KeyGroupId></Items>

<!-- after -->
<Quantity>2</Quantity>
<Items><KeyGroupId>kg-1</KeyGroupId><KeyGroupId>kg-2</KeyGroupId></Items>

Defensive patterns

Strategy: validation

Validate before calling

static void checkQuantityMatches(Integer declared, List<String> items) {
    if (declared == null || declared != items.size()) {
        throw new IllegalArgumentException(
            "Quantity " + declared + " != item count " + items.size());
    }
}

Try / catch

try {
    cf.updateDistribution(req -> req.id(id).ifMatch(etag).distributionConfig(cfg));
} catch (CloudFrontException e) {
    if ("InconsistentQuantities".equals(e.awsErrorDetails().errorCode())) {
        // set Quantity = items.size() and retry once
    } else { throw e; }
}

Prevention

Derive Quantity from the same list object you serialize, at serialization time
Never hand-edit one of Quantity/Items without updating the other

When it happens

Trigger: Sending <Quantity>3</Quantity> with only 2 KeyGroupId items (or vice versa) in DefaultCacheBehavior or any CacheBehavior's TrustedKeyGroups.

Common situations: Hardcoded Quantity that goes stale when items are added/removed; hand-merged configs where the list changed but the count was not updated.

Related errors

AI-assisted analysis of floci-io/floci@62ff490619 (2026-08-14). Data as JSON: /api/errors/5b428656074deae4. Report an issue: GitHub.