(initial Prometheus author here) I wouldn't totally rule out the pushgateway for this use case. If we decided to implement a metrics timeout in the pushgateway

(initial Prometheus author here) I wouldn't totally rule out the pushgateway for this use case. If we decided to implement a metrics timeout in the pushgateway (https://github.com/prometheus/pushgateway/issues/19 https://github.com/prometheus/pushgateway/issues/19), this would also take care of stale metrics from targets that are down or decommissioned. The pushing clients would probably even want to set a client-side timestamp in that case, as they are expected to be pushing regularly enough for the timestamp to not become stale (currently Prometheus considers time series stale that are >5 minutes old by default, see also the "Improved staleness handling" item in http://prometheus.io/docs/introduction/roadmap/ http://prometheus.io/docs/introduction/roadmap/.