feat(cluster): expose replicationSlots on the CNPG Cluster#877
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philippemnoel wants to merge 1 commit into
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feat(cluster): expose replicationSlots on the CNPG Cluster#877philippemnoel wants to merge 1 commit into
philippemnoel wants to merge 1 commit into
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Surfaces CloudNativePG's `spec.replicationSlots` on the cluster chart so chart users can enable synchronization of user-created logical replication slots between the primary and standbys. With PostgreSQL 17+ failover slots, this lets CDC consumers (e.g. Debezium) survive a CNPG failover without losing the slot. To make logical decoding slots survive failover, users must: - enable `cluster.replicationSlots.highAvailability.synchronizeLogicalDecoding` - set `cluster.postgresql.parameters.hot_standby_feedback: "on"` - set `cluster.postgresql.parameters.sync_replication_slots: "on"` - create the CDC client's logical slot with `failover = true` Requires CloudNativePG 1.27+ and PostgreSQL 17+ for native failover slots. The block is omitted entirely when the value is empty, so existing deployments are unaffected. The non-default-configuration chainsaw test is extended with a `replicationSlots` block and the matching PostgreSQL parameters, and asserts they appear verbatim on the rendered Cluster CR. Signed-off-by: Philippe Noël <philippemnoel@gmail.com>
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What
Cluster.spec.replicationSlotson theclusterchart throughcluster.replicationSlots.Why
CDC tools (Debezium, Artie, etc.) create and consume a logical replication slot on the current primary. Before this change, a CNPG switchover or failover could leave that logical slot behind on the old primary, which then becomes a replica. CDC stops reconnecting cleanly and the abandoned slot can continue retaining WAL.
CloudNativePG can coordinate logical decoding slot synchronization across HA instances via
spec.replicationSlots, but theclusterchart did not previously surface that field, so chart users had no way to enable it without bypassing the chart.Requirements for CDC failover
cluster.replicationSlots.highAvailability.synchronizeLogicalDecoding: true.cluster.postgresql.parameters.hot_standby_feedback: "on".cluster.postgresql.parameters.sync_replication_slots: "on".failover = true; CNPG cannot move a normal non-failover logical slot.synced = true,temporary = false, andinvalidation_reason IS NULL.Backwards compatibility
cluster.replicationSlotsdefaults to{}, and the template uses{{- with ... }}so the block is omitted entirely when unset. Existing deployments render identically.Tests
helm lint charts/clusterhelm template test charts/cluster --show-only templates/cluster.yaml(noreplicationSlotsrendered by default)helm template test charts/cluster --show-only templates/cluster.yaml --values charts/cluster/test/postgresql-cluster-configuration/01-non_default_configuration_cluster.yaml(rendersreplicationSlotsverbatim)postgresql-cluster-configurationtest now asserts the renderedreplicationSlotsblock.