How can I call directly CloudWatch from a step function? - amazon-cloudwatch

Question

I have a step function that catches an eventual failure from a Glue function (fallback):
{
"Comment": "A Hello World example demonstrating various state types of the Amazon States Language",
"StartAt": "Parallel State",
"States": {
"Parallel State": {
"Comment": "A Parallel state can be used to create parallel branches of execution in your state machine.",
"Type": "Parallel",
"Branches": [
{
"StartAt": "Wait",
"States": {
"Wait": {
"Type": "Wait",
"Seconds": 500,
"Next": "Glue StartJobRun SUCCESS"
},
"Glue StartJobRun SUCCESS": {
"Type": "Task",
"Resource": "arn:aws:states:::glue:startJobRun.sync",
"Parameters": {
"JobName": "job_success"
},
"End": true,
"Credentials": {
"RoleArn": "arn:aws:iam::094815468753:role/glue_test"
}
}
}
},
{
"StartAt": "Glue StartJobRun FAIL",
"States": {
"Glue StartJobRun FAIL": {
"Type": "Task",
"Resource": "arn:aws:states:::glue:startJobRun.sync",
"Catch": [ {
"ErrorEquals": ["States.TaskFailed"],
"Next": "fallback"
} ],
"Parameters": {
"JobName": "job_fail"
},
"End": true,
"Credentials": {
"RoleArn": "arn:aws:iam::094815468753:role/glue_test"
}
},
"fallback": {
"Type": "Pass",
"Result": "ERROR HERE",
"End": true
}
}
}
],
"Next": "Pass"
},
"Pass": {
"Type": "Pass",
"End": true
}
}
}
when the fallback is called, how can I send from there a metric data to CloudWatch?

Answer 1

You can call the CloudWatch PutMetricData API from a Step Functions Task with the so-called AWS SDK service integration. The request parameters go in the task's Parameters key.
{
"PutMetricData": {
"Next": "Success",
"Type": "Task",
"Resource": "arn:aws:states:::aws-sdk:cloudwatch:putMetricData",
"Parameters": {
"MetricData": [
{ "MetricName": "FooMetric", "Value": 1 },
{ "MetricName": "FooMetric", "Value.$": "$.foo" }
],
"Namespace": "Dummy"
}
}
}

Answer 2

You can not put metric from Step Function to Cloudwatch metrics.
But you can do it in this way.
Create a lambda function
Call lambda function on failure
Lambda function put metric to cloudwatch