AWS Glue not emitting events on Cloudwatch

Could you please check if glue service role has sufficient permissions to put data to cloudwatch.

If you are not using AWS managed policy AWSGlueServiceRole in your glue service role, then I'd suggest you to go through this documentation Create an IAM policy for the AWS Glue service and make sure glue service role has these permissions at least.

    {
        "Version": "2012-10-17",
        "Statement": [
            {
                "Effect": "Allow",
                "Action": [
                    "glue:*",
                    "s3:GetBucketLocation",
                    "s3:ListBucket",
                    "s3:ListAllMyBuckets",
                    "s3:GetBucketAcl",
                    "ec2:DescribeVpcEndpoints",
                    "ec2:DescribeRouteTables",
                    "ec2:CreateNetworkInterface",
                    "ec2:DeleteNetworkInterface",				
                    "ec2:DescribeNetworkInterfaces",
                    "ec2:DescribeSecurityGroups",
                    "ec2:DescribeSubnets",
                    "ec2:DescribeVpcAttribute",
                    "iam:ListRolePolicies",
                    "iam:GetRole",
                    "iam:GetRolePolicy",
                    "cloudwatch:PutMetricData"                
                ],
                "Resource": [
                    "*"
                ]
            },
            {
                "Effect": "Allow",
                "Action": [
                    "s3:CreateBucket",
                    "s3:PutBucketPublicAccessBlock"
                ],
                "Resource": [
                    "arn:aws:s3:::aws-glue-*"
                ]
            },
            {
                "Effect": "Allow",
                "Action": [
                    "s3:GetObject",
                    "s3:PutObject",
                    "s3:DeleteObject"				
                ],
                "Resource": [
                    "arn:aws:s3:::aws-glue-*/*",
                    "arn:aws:s3:::*/*aws-glue-*/*"
                ]
            },
            {
                "Effect": "Allow",
                "Action": [
                    "s3:GetObject"
                ],
                "Resource": [
                    "arn:aws:s3:::crawler-public*",
                    "arn:aws:s3:::aws-glue-*"
                ]
            },
            {
                "Effect": "Allow",
                "Action": [
                    "logs:CreateLogGroup",
                    "logs:CreateLogStream",
                    "logs:PutLogEvents",
                    "logs:AssociateKmsKey"                
                ],
                "Resource": [
                    "arn:aws:logs:*:*:log-group:/aws-glue/*"
                ]
            },
            {
                "Effect": "Allow",
                "Action": [
                    "ec2:CreateTags",
                    "ec2:DeleteTags"
                ],
                "Condition": {
                    "ForAllValues:StringEquals": {
                        "aws:TagKeys": [
                            "aws-glue-service-resource"
                        ]
                    }
                },
                "Resource": [
                    "arn:aws:ec2:*:*:network-interface/*",
                    "arn:aws:ec2:*:*:security-group/*",
                    "arn:aws:ec2:*:*:instance/*"
                ]
            }
        ]
    }

You can further trim it down, but this should be your starting point.

Hope it helps.

Comment here if you have additional questions, happy to help.

Abhishek