Since CloudWatch metrics only has 15 months of data retention, in order to see a longer metrics change and use metrics in other flexible ways, we would like to export metrics from CloudWatch to AWS managed Prometheus.
The simplest way may be to use an OpenTelemetry collector to scrape metrics from CloudWatch and send to AWS managed Prometheus. But I don't see any OpenTelemetry receiver that can scrape metrics from CloudWatch directly. Is this idea a feasible way to solve my problem?
I would say scraping is not the best approach. AWS offers CloudWatch Metric Streams, so you can continually stream CloudWatch metrics to a destination of your choice. My blind guess for the pipeline, which you can use: CloudWatch Metric Stream -> Kinesis Data Firehose -> Lambda -> AWS managed Prometheus.
To keep AWS metric data more then 15 month with 1 min of data point, I use telegraf (data agent) and influxDB(for data stored) and Grafana for Visuallization. its a easy process to keep historical metric data at lower cost. If you think this solution is fiesble for you then this telegraf config might help you. https://github.com/influxdata/telegraf/blob/master/plugins/inputs/cloudwatch/README.md
