AWS scheduler documentation change

Service: scheduler · 2026-03-13 · Documentation low

File: scheduler/latest/UserGuide/troubleshooting.md

Summary

Added section about invalid universal target input configurations with resolution guidance

Security assessment

Addresses potential misconfigurations in target input parameters but doesn't relate to security vulnerabilities. Focuses on operational reliability rather than security features.

Diff

diff --git a/scheduler/latest/UserGuide/troubleshooting.md b/scheduler/latest/UserGuide/troubleshooting.md
index f4bea63f5..c2641cdc4 100644
--- a//scheduler/latest/UserGuide/troubleshooting.md
+++ b//scheduler/latest/UserGuide/troubleshooting.md
@@ -5 +5 @@
-Target errorsRole permissionsService quotasPattern and trigger timingCreating patternsIs my target being triggered?Templated vs universal targetsSchedule updates triggering unexpected invocationsDisabling or enabling one-time schedules
+Target errorsRole permissionsService quotasPattern and trigger timingCreating patternsIs my target being triggered?Templated vs universal targetsInvalid universal target inputSchedule updates triggering unexpected invocationsDisabling or enabling one-time schedules
@@ -26,0 +27,2 @@ You can use the topics in this section to troubleshoot common Amazon EventBridge
+  * Invalid universal target input configurations
+
@@ -413,0 +416,71 @@ To resolve this:
+## Invalid universal target input configurations
+
+When you create a schedule with a [universal target](./managing-targets-universal.html), EventBridge Scheduler validates the target ARN format but does not validate the contents of the `Input` field against the downstream service's API. This means a schedule can be created successfully even if the `Input` contains values that the target service will reject at invocation time.
+
+Schedules with invalid target input configurations are triggered on their configured expression but fail on every invocation. You may not discover the misconfiguration until the schedule is invoked, which could be hours or days after creation.
+
+### Symptoms
+
+  * The schedule was created without errors, but the `TargetErrorCount` CloudWatch metric increases on every invocation.
+
+  * DLQ messages contain error codes from the target service (for example, `InvalidParameterValueException` or `ValidationException`), not `AWS.Scheduler.InternalServerError`.
+
+  * The `ERROR_MESSAGE` in the DLQ message references specific input parameter validation failures.
+
+
+
+
+### Examples
+
+The following examples show common invalid input configurations for a AWS Lambda universal target (`arn:aws:scheduler:::aws-sdk:lambda:invoke`).
+
+**Mismatching qualifiers**
+
+A schedule with the following input specifies version `2` in the `FunctionName` and version `1` in the `Qualifier` field:
+    
+    
+    {
+        "FunctionName": "MyFunction:2",
+        "Qualifier": "1"
+    }
+
+This schedule is created successfully, but every invocation fails. The DLQ message contains:
+
+  * `ERROR_CODE`: `InvalidParameterValueException`
+
+  * `ERROR_MESSAGE`: `The derived qualifier from the function name does not match the specified qualifier.`
+
+
+
+
+**Invalid function name**
+
+A schedule with the following input specifies a whitespace-only value for `FunctionName`:
+    
+    
+    {
+        "FunctionName": "     "
+    }
+
+The DLQ message contains:
+
+  * `ERROR_CODE`: `ValidationException`
+
+  * `ERROR_MESSAGE`: A validation error indicating the function name does not match the required pattern.
+
+
+
+
+### How to resolve
+
+  1. **Configure a DLQ.** Always [configure a dead-letter queue](./configuring-schedule-dlq.html) for schedules that use universal targets. The DLQ message attributes (`ERROR_CODE` and `ERROR_MESSAGE`) contain the specific error returned by the target service, which identifies the invalid input parameter.
+
+  2. **Validate input parameters against the target service API.** Before creating a schedule, verify that the JSON in your `Input` field contains valid values by calling the target API directly. For example, invoke your AWS Lambda function with the same parameters using the AWS Lambda `Invoke` API to confirm the request succeeds.
+
+  3. **Test with a one-time schedule.** Create a one-time schedule to verify that the target invocation succeeds before configuring a recurring schedule.
+
+  4. **Review the target service API reference.** Check the API reference for the service you are targeting to confirm required parameters, valid value ranges, and constraints. For AWS Lambda `Invoke`, see [Invoke](https://docs.aws.amazon.com/lambda/latest/dg/API_Invoke.html) in the _AWS Lambda Developer Guide_.
+
+
+
+