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fix(metrics): skip pg_stat_archiver metrics on non-archiving standbys - #9411

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@armru armru commented Dec 12, 2025

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After a PostgreSQL instance is demoted from primary to standby, the pg_stat_archiver view retains stale data from when the instance was archiving WAL files. This causes misleading metrics and false alerts (e.g., "last archive age > 7 minutes") on standby nodes that do not actively archive WAL.

This fix adds a predicate_query to the pg_stat_archiver metrics collection that only runs the query on instances that actually perform WAL archiving:

  • Primary instances (not in recovery)
  • Designated primary replicas (archive_mode='always' in replica clusters)

Regular standby nodes will no longer export pg_stat_archiver metrics, preventing stale data from triggering false alerts.

Fixes #9101

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armru requested review from a team and Copilot December 12, 2025 13:09
@dosubot dosubot Bot added the size:XS This PR changes 0-9 lines, ignoring generated files. label Dec 12, 2025
@cnpg-bot cnpg-bot added backport-requested ◀️ This pull request should be backported to all supported releases release-1.25 release-1.28 labels Dec 12, 2025
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❗ By default, the pull request is configured to backport to all release branches.

  • To stop backporting this pr, remove the label: backport-requested ◀️ or add the label 'do not backport'
  • To stop backporting this pr to a certain release branch, remove the specific branch label: release-x.y

@dosubot dosubot Bot added the bug 🐛 Something isn't working label Dec 12, 2025

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Pull request overview

This PR fixes an issue where PostgreSQL instances demoted from primary to standby retain stale pg_stat_archiver metrics, leading to false alerts on non-archiving standby nodes.

Key Changes:

  • Added a predicate_query to pg_stat_archiver metrics collection that ensures metrics are only gathered from instances actively performing WAL archiving
  • The predicate correctly identifies primary instances and designated primary replicas (with archive_mode='always')

@dosubot dosubot Bot added the lgtm This PR has been approved by a maintainer label Dec 12, 2025
After a PostgreSQL instance is demoted from primary to standby, the
pg_stat_archiver view retains stale data from when the instance was
archiving WAL files. This causes misleading metrics and false alerts
(e.g., "last archive age > 7 minutes") on standby nodes that do not
actively archive WAL.

This fix adds a predicate_query to the pg_stat_archiver metrics
collection that only runs the query on instances that actually perform
WAL archiving:
- Primary instances (not in recovery)
- Designated primary replicas (archive_mode='always' in replica clusters)

Regular standby nodes will no longer export pg_stat_archiver metrics,
preventing stale data from triggering false alerts.

Fixes #9101

Signed-off-by: Armando Ruocco <[email protected]>
@gbartolini
gbartolini merged commit e2d6bd0 into main Dec 16, 2025
20 of 24 checks passed
@gbartolini
gbartolini deleted the dev/9101 branch December 16, 2025 15:36
cnpg-bot pushed a commit that referenced this pull request Dec 16, 2025
…ys (#9411)

After a PostgreSQL instance is demoted from primary to standby, the
`pg_stat_archiver` view retains stale data from when the instance was
archiving WAL files. This causes misleading metrics and false alerts
(e.g., "last archive age > 7 minutes") on standby nodes that do not
actively archive WAL.

This fix adds a predicate_query to the `pg_stat_archiver` metrics
collection that only runs the query on instances that actually perform
WAL archiving:

- Primary instances (not in recovery)
- Designated primary replicas (archive_mode='always' in replica
   clusters)

Regular standby nodes will no longer export `pg_stat_archiver` metrics,
preventing stale data from triggering false alerts.

Fixes #9101

Signed-off-by: Armando Ruocco <[email protected]>
(cherry picked from commit e2d6bd0)
cnpg-bot pushed a commit that referenced this pull request Dec 16, 2025
…ys (#9411)

After a PostgreSQL instance is demoted from primary to standby, the
`pg_stat_archiver` view retains stale data from when the instance was
archiving WAL files. This causes misleading metrics and false alerts
(e.g., "last archive age > 7 minutes") on standby nodes that do not
actively archive WAL.

This fix adds a predicate_query to the `pg_stat_archiver` metrics
collection that only runs the query on instances that actually perform
WAL archiving:

- Primary instances (not in recovery)
- Designated primary replicas (archive_mode='always' in replica
   clusters)

Regular standby nodes will no longer export `pg_stat_archiver` metrics,
preventing stale data from triggering false alerts.

Fixes #9101

Signed-off-by: Armando Ruocco <[email protected]>
(cherry picked from commit e2d6bd0)
cnpg-bot pushed a commit that referenced this pull request Dec 16, 2025
…ys (#9411)

After a PostgreSQL instance is demoted from primary to standby, the
`pg_stat_archiver` view retains stale data from when the instance was
archiving WAL files. This causes misleading metrics and false alerts
(e.g., "last archive age > 7 minutes") on standby nodes that do not
actively archive WAL.

This fix adds a predicate_query to the `pg_stat_archiver` metrics
collection that only runs the query on instances that actually perform
WAL archiving:

- Primary instances (not in recovery)
- Designated primary replicas (archive_mode='always' in replica
   clusters)

Regular standby nodes will no longer export `pg_stat_archiver` metrics,
preventing stale data from triggering false alerts.

Fixes #9101

Signed-off-by: Armando Ruocco <[email protected]>
(cherry picked from commit e2d6bd0)
@leonardoce

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Should we decide to loosen the requirement, I implemented #9475 to align the E2e tests.

mnencia pushed a commit that referenced this pull request Jan 20, 2026
…ys (#9411)

After a PostgreSQL instance is demoted from primary to standby, the
`pg_stat_archiver` view retains stale data from when the instance was
archiving WAL files. This causes misleading metrics and false alerts
(e.g., "last archive age > 7 minutes") on standby nodes that do not
actively archive WAL.

This fix adds a predicate_query to the `pg_stat_archiver` metrics
collection that only runs the query on instances that actually perform
WAL archiving:

- Primary instances (not in recovery)
- Designated primary replicas (archive_mode='always' in replica
   clusters)

Regular standby nodes will no longer export `pg_stat_archiver` metrics,
preventing stale data from triggering false alerts.

Fixes #9101

Signed-off-by: Armando Ruocco <[email protected]>
(cherry picked from commit e2d6bd0)
renovate Bot added a commit to sdwilsh/ansible-playbooks that referenced this pull request Mar 26, 2026
##### [\`v1.28.1\`](https://github.com/cloudnative-pg/cloudnative-pg/releases/tag/v1.28.1)

**Release date:** Feb 5, 2026

##### Enhancements

- Added support for Azure's `DefaultAzureCredential` authentication mechanism for backup and recovery operations. This can be enabled by setting `azureCredentials.useDefaultAzureCredentials: true` in the backup configuration, simplifying authentication in Azure environments without requiring explicit storage account keys or SAS tokens. ([#9468](cloudnative-pg/cloudnative-pg#9468)) <!-- 1.27 1.25 -->

##### Fixes

- Fixed validation of PostgreSQL extension names containing underscores (e.g., `pg_partman`, `pg_ivm`). Extension names with underscores are automatically sanitized to use hyphens for Kubernetes volume names while preserving the original name in mount paths. Webhook validation prevents naming conflicts after sanitization. Contributed by [@shusaan](https://github.com/shusaan). ([#9386](cloudnative-pg/cloudnative-pg#9386)) <!-- 1.27 -->

- Fixed a critical issue where the `TimelineID` in the cluster status was not reset to 1 after a major version upgrade. Because `pg_upgrade` initializes a new timeline, keeping the old ID (e.g., timeline 2) caused replicas to attempt to restore incompatible history files from object storage, leading to fatal "requested timeline is not a child of this server's history" errors. ([#9830](cloudnative-pg/cloudnative-pg#9830)) <!-- 1.27 -->

- Fixed an issue where stale TLS status fields in the `Pooler` were not cleared after being removed from the specification. This was particularly critical when upgrading to v1.28.0, where the `ServerTLS` field was repurposed, causing PgBouncer to use incorrect certificates and resulting in "unsupported certificate" errors that blocked all application connectivity. The operator now explicitly clears `ServerCA`, `ClientCA`, `ClientTLS`, and `ServerTLS` status fields when they are no longer configured. ([#9397](cloudnative-pg/cloudnative-pg#9397))

- Fixed a bug where replicas could enter a crash-loop by attempting to download timeline history files from future timelines. This occurred when stale files remained in the WAL archive from a previous cluster life, and replicas would incorrectly try to fetch them during recovery. ([#9650](cloudnative-pg/cloudnative-pg#9650)) <!-- 1.27 1.25 -->

- Fixed a race condition in `replica_cluster` setups during designated primary transitions, preventing transient "no primary" states in the replica cluster. ([#9601](cloudnative-pg/cloudnative-pg#9601)) <!-- 1.27 1.25 -->

- The backup controller now uses the unique instance session ID to detect instance manager restarts. This prevents the operator from incorrectly assuming a backup is still progressing if the underlying container has crashed and restarted, which previously led to orphaned backup objects. ([#9370](cloudnative-pg/cloudnative-pg#9370)) <!-- 1.27 -->

- Fixed a validation gap in Azure object store configurations where the `storageAccount` was not required when using explicit credentials (such as a storage key or SAS token). The operator now enforces that a storage account name is provided in these cases and that `connectionString` is mutually exclusive with other authentication parameters. ([#9604](cloudnative-pg/cloudnative-pg#9604)) <!-- 1.27 1.25 -->

- Optimized the deletion path so the operator begins cleaning up resources immediately when a cluster is marked for deletion. This significantly reduces the time a cluster remains in `Terminating` status while waiting for internal reconciliation loops. ([#9555](cloudnative-pg/cloudnative-pg#9555)) <!-- 1.27 1.25 -->

- Fixed an issue where replication slots were not properly dropped from replicas when the feature was disabled or the cluster was reconfigured. This ensures that unused slots do not cause WAL build-up on the primary. ([#9381](cloudnative-pg/cloudnative-pg#9381)) <!-- 1.27 1.25 -->

- Fixed an issue where `imagePullSecrets` were not added to the `ServiceAccount` created for the `Pooler`. Previously, these secrets were applied to the Deployment but not the SA, which caused image pull failures in restricted environments using certain security policies. ([#9427](cloudnative-pg/cloudnative-pg#9427)) <!-- 1.27 1.25 -->

- Added a check to verify ownership before the operator deletes a `PodMonitor`. This prevents the operator from accidentally deleting manually managed monitoring resources that happen to share a name with expected CNPG resources. Contributed by [@juliamertz](https://github.com/juliamertz). ([#9340](cloudnative-pg/cloudnative-pg#9340)) <!-- 1.27 1.25 -->

- Fixed a bug where `pg_stat_archiver` metrics would continue to report stale data on standby instances after a switchover. The exporter now skips these metrics on standbys, as PostgreSQL only provides valid archiver stats on the primary. ([#9411](cloudnative-pg/cloudnative-pg#9411)) <!-- 1.27 1.25 -->

- Clarified the interpretation of timestamp formats for recovery `targetTime`. Timestamps provided without an explicit timezone are now consistently interpreted as UTC. Contributed by [@pchovelon](https://github.com/pchovelon). ([#8937](cloudnative-pg/cloudnative-pg#8937)) <!-- 1.27 1.25 -->

- Fixed backup status updates to prevent "resource has been modified" errors during concurrent updates. ([#9551](cloudnative-pg/cloudnative-pg#9551)) <!-- 1.27 1.25 -->

- Fixed event reporting to use the correct pod name when a backup pod is not found. ([#9552](cloudnative-pg/cloudnative-pg#9552)) <!-- 1.27 1.25 -->

- Improved performance of scheduled backup operations for clusters with a very high number of historical backups. ([#9489](cloudnative-pg/cloudnative-pg#9489)) <!-- 1.27 1.25 -->

- Fixed error handling when removing finalizers on `Database` objects. ([#9431](cloudnative-pg/cloudnative-pg#9431)) <!-- 1.27 1.25 -->

- `cnpg` plugin:

  - Updated the `status` command to display "Disabled" when the `skipWalArchiving` annotation is present on a cluster. This replaces confusing "starting up" or "unknown" states when WAL archiving is intentionally bypassed. ([#9709](cloudnative-pg/cloudnative-pg#9709)) <!-- 1.27 1.25 -->

  - Fixed the `logs --follow` command to continue polling for new pods instead of exiting prematurely when all current log streams complete. ([#9599](cloudnative-pg/cloudnative-pg#9599)) <!-- 1.27 1.25 -->
sdwilsh pushed a commit to sdwilsh/ansible-playbooks that referenced this pull request Mar 26, 2026
##### [\`v1.28.1\`](https://github.com/cloudnative-pg/cloudnative-pg/releases/tag/v1.28.1)

**Release date:** Feb 5, 2026

##### Enhancements

- Added support for Azure's `DefaultAzureCredential` authentication mechanism for backup and recovery operations. This can be enabled by setting `azureCredentials.useDefaultAzureCredentials: true` in the backup configuration, simplifying authentication in Azure environments without requiring explicit storage account keys or SAS tokens. ([#9468](cloudnative-pg/cloudnative-pg#9468)) <!-- 1.27 1.25 -->

##### Fixes

- Fixed validation of PostgreSQL extension names containing underscores (e.g., `pg_partman`, `pg_ivm`). Extension names with underscores are automatically sanitized to use hyphens for Kubernetes volume names while preserving the original name in mount paths. Webhook validation prevents naming conflicts after sanitization. Contributed by [@shusaan](https://github.com/shusaan). ([#9386](cloudnative-pg/cloudnative-pg#9386)) <!-- 1.27 -->

- Fixed a critical issue where the `TimelineID` in the cluster status was not reset to 1 after a major version upgrade. Because `pg_upgrade` initializes a new timeline, keeping the old ID (e.g., timeline 2) caused replicas to attempt to restore incompatible history files from object storage, leading to fatal "requested timeline is not a child of this server's history" errors. ([#9830](cloudnative-pg/cloudnative-pg#9830)) <!-- 1.27 -->

- Fixed an issue where stale TLS status fields in the `Pooler` were not cleared after being removed from the specification. This was particularly critical when upgrading to v1.28.0, where the `ServerTLS` field was repurposed, causing PgBouncer to use incorrect certificates and resulting in "unsupported certificate" errors that blocked all application connectivity. The operator now explicitly clears `ServerCA`, `ClientCA`, `ClientTLS`, and `ServerTLS` status fields when they are no longer configured. ([#9397](cloudnative-pg/cloudnative-pg#9397))

- Fixed a bug where replicas could enter a crash-loop by attempting to download timeline history files from future timelines. This occurred when stale files remained in the WAL archive from a previous cluster life, and replicas would incorrectly try to fetch them during recovery. ([#9650](cloudnative-pg/cloudnative-pg#9650)) <!-- 1.27 1.25 -->

- Fixed a race condition in `replica_cluster` setups during designated primary transitions, preventing transient "no primary" states in the replica cluster. ([#9601](cloudnative-pg/cloudnative-pg#9601)) <!-- 1.27 1.25 -->

- The backup controller now uses the unique instance session ID to detect instance manager restarts. This prevents the operator from incorrectly assuming a backup is still progressing if the underlying container has crashed and restarted, which previously led to orphaned backup objects. ([#9370](cloudnative-pg/cloudnative-pg#9370)) <!-- 1.27 -->

- Fixed a validation gap in Azure object store configurations where the `storageAccount` was not required when using explicit credentials (such as a storage key or SAS token). The operator now enforces that a storage account name is provided in these cases and that `connectionString` is mutually exclusive with other authentication parameters. ([#9604](cloudnative-pg/cloudnative-pg#9604)) <!-- 1.27 1.25 -->

- Optimized the deletion path so the operator begins cleaning up resources immediately when a cluster is marked for deletion. This significantly reduces the time a cluster remains in `Terminating` status while waiting for internal reconciliation loops. ([#9555](cloudnative-pg/cloudnative-pg#9555)) <!-- 1.27 1.25 -->

- Fixed an issue where replication slots were not properly dropped from replicas when the feature was disabled or the cluster was reconfigured. This ensures that unused slots do not cause WAL build-up on the primary. ([#9381](cloudnative-pg/cloudnative-pg#9381)) <!-- 1.27 1.25 -->

- Fixed an issue where `imagePullSecrets` were not added to the `ServiceAccount` created for the `Pooler`. Previously, these secrets were applied to the Deployment but not the SA, which caused image pull failures in restricted environments using certain security policies. ([#9427](cloudnative-pg/cloudnative-pg#9427)) <!-- 1.27 1.25 -->

- Added a check to verify ownership before the operator deletes a `PodMonitor`. This prevents the operator from accidentally deleting manually managed monitoring resources that happen to share a name with expected CNPG resources. Contributed by [@juliamertz](https://github.com/juliamertz). ([#9340](cloudnative-pg/cloudnative-pg#9340)) <!-- 1.27 1.25 -->

- Fixed a bug where `pg_stat_archiver` metrics would continue to report stale data on standby instances after a switchover. The exporter now skips these metrics on standbys, as PostgreSQL only provides valid archiver stats on the primary. ([#9411](cloudnative-pg/cloudnative-pg#9411)) <!-- 1.27 1.25 -->

- Clarified the interpretation of timestamp formats for recovery `targetTime`. Timestamps provided without an explicit timezone are now consistently interpreted as UTC. Contributed by [@pchovelon](https://github.com/pchovelon). ([#8937](cloudnative-pg/cloudnative-pg#8937)) <!-- 1.27 1.25 -->

- Fixed backup status updates to prevent "resource has been modified" errors during concurrent updates. ([#9551](cloudnative-pg/cloudnative-pg#9551)) <!-- 1.27 1.25 -->

- Fixed event reporting to use the correct pod name when a backup pod is not found. ([#9552](cloudnative-pg/cloudnative-pg#9552)) <!-- 1.27 1.25 -->

- Improved performance of scheduled backup operations for clusters with a very high number of historical backups. ([#9489](cloudnative-pg/cloudnative-pg#9489)) <!-- 1.27 1.25 -->

- Fixed error handling when removing finalizers on `Database` objects. ([#9431](cloudnative-pg/cloudnative-pg#9431)) <!-- 1.27 1.25 -->

- `cnpg` plugin:

  - Updated the `status` command to display "Disabled" when the `skipWalArchiving` annotation is present on a cluster. This replaces confusing "starting up" or "unknown" states when WAL archiving is intentionally bypassed. ([#9709](cloudnative-pg/cloudnative-pg#9709)) <!-- 1.27 1.25 -->

  - Fixed the `logs --follow` command to continue polling for new pods instead of exiting prematurely when all current log streams complete. ([#9599](cloudnative-pg/cloudnative-pg#9599)) <!-- 1.27 1.25 -->
@dosubot dosubot Bot mentioned this pull request Apr 24, 2026
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[Bug]:pg_stat_archiver metrics not reset after demotion (former primary still reports stale archive age)

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