Design Records on PG Exporter https://exp.pgsty.com/design/ Recent content in Design Records on PG Exporter Hugo en-US Mon, 09 Nov 2026 00:00:00 +0800 Bounded SQL Scrapes and Client Cancellation https://exp.pgsty.com/design/scrape-lifetime/ Mon, 09 Nov 2026 00:00:00 +0800 Vonng https://exp.pgsty.com/design/scrape-lifetime/ v1.6.0: bounded waiting for two scrapers, request cancellation, and the existing failure-cache policy. Cluster Progress with Safe Relation Labels https://exp.pgsty.com/design/progress-database-scope/ Mon, 09 Nov 2026 00:00:00 +0800 Vonng https://exp.pgsty.com/design/progress-database-scope/ v1.6.0: keep cluster-wide progress and use numeric OIDs for user relations in other databases. Container Trust Roots and Release Checks https://exp.pgsty.com/design/container-trust/ Sun, 08 Nov 2026 00:00:00 +0800 Vonng https://exp.pgsty.com/design/container-trust/ v1.6.0: include CA roots and the license in both scratch images, and exercise TLS and DEB artifacts in release validation. Target Identity and Consistent Health Responses https://exp.pgsty.com/design/target-state-contracts/ Fri, 23 Oct 2026 00:00:00 +0800 Vonng https://exp.pgsty.com/design/target-state-contracts/ v1.5.0 target-state guarantees, with the v1.6.0 amendment separating health probes from collection. Correcting Replication Collector Identity and Semantics https://exp.pgsty.com/design/replication-collector-contracts/ Thu, 22 Oct 2026 00:00:00 +0800 Vonng https://exp.pgsty.com/design/replication-collector-contracts/ Shipped in v1.5.0. Add database identity to subscriptions, correct receiver mappings, and clarify optional permissions and table/sequence counts. Turning PostgreSQL CSV Logs into Durable Metrics https://exp.pgsty.com/design/postgres-log-metrics/ Mon, 24 Aug 2026 12:17:38 +0800 Vonng https://exp.pgsty.com/design/postgres-log-metrics/ Implemented but unreleased. A default-off worker persists CSV cursors and aggregates before publishing cumulative log metrics. Caching pgBackRest Metrics Outside the Scrape Path https://exp.pgsty.com/design/cached-pgbackrest-metrics/ Sun, 23 Aug 2026 19:34:09 +0800 Vonng https://exp.pgsty.com/design/cached-pgbackrest-metrics/ Implemented but unreleased. Background collection keeps command and repository latency out of Prometheus requests. Failed refreshes retain the last valid backup state. The PostgreSQL Observability Product We Chose Not to Build https://exp.pgsty.com/design/observability-product-pivot/ Thu, 13 Aug 2026 14:17:01 +0800 Vonng https://exp.pgsty.com/design/observability-product-pivot/ Superseded on 2026-08-24. CSV parsing and durable-state requirements became a bounded log-metrics feature; the separate product was dropped. One Endpoint, Several Sources: The Composite Exporter Contract https://exp.pgsty.com/design/composite-exporter/ Tue, 11 Aug 2026 23:50:55 +0800 Vonng https://exp.pgsty.com/design/composite-exporter/ Implemented but unreleased. PostgreSQL remains authoritative. Live sources share a timeout; cached sources publish immutable snapshots. Snapshot Histograms Are Gauges, Not Counters https://exp.pgsty.com/design/snapshot-histograms/ Sat, 11 Jul 2026 22:06:29 +0800 Vonng https://exp.pgsty.com/design/snapshot-histograms/ Shipped in v1.4.0. Each SQL execution builds a fresh distribution. Buckets, count, and sum are Gauges and can decrease between scrapes.