Custom metrics and dimensions

Your deployment team at NovaTech publishes pipeline timing data to CloudWatch as custom metrics so they can graph regressions on a dashboard. A custom metric is identified by its namespace, metric name, and dimensions — and that identity is what determines how many distinct (billable) metrics you create.

Use the billable metric counter to publish data points with different metric names and Pipeline dimension values, and watch the billable-metric count. Re-publishing the same combination does not add a metric, while a new dimension value does.

Question: If you publish stepDuration with dimension Pipeline=ProdApp01 AND separately with dimension Pipeline=ProdApp02, how many billable custom metrics does this create?