Klio Overview

warning

Klio is experimental and under active development. APIs, CRDs, and behavior may change without notice, and it is not yet recommended for production use.

Klio is a cloud-native solution for enterprise-grade backup and recovery of PostgreSQL databases managed by CloudNativePG on Kubernetes. It is designed to handle:

• The Write-Ahead Log (WAL) archive for a given PostgreSQL Cluster resource, within the same Kubernetes namespace as the Klio deployment
• The catalog of physical base backups for that same cluster
• Optionally, multiple PostgreSQL clusters

These critical backup artifacts are stored across two distinct storage tiers:

• Tier 1 – Local Volume: A local Persistent Volume (PV) within the same namespace as the associated Cluster resource. It offers immediate, high-throughput access for backup and recovery operations. Also referred to as the Main Tier or Klio Server.

• Tier 2 – Secondary Storage: An external object storage system where data from Tier 1 is asynchronously replicated. This tier typically resides outside the Kubernetes cluster, enabling geographical redundancy and enhancing disaster recovery (DR) resilience.

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Key Features

WAL Management

• Native WAL streaming from the primary, eliminating the need for archive_command, with support for:
  • Partial WAL file handling
  • WAL file compression
  • WAL file encryption using user-provided keys
  • Controlled replication slot advancement to ensure uninterrupted streaming
  • Synchronous replication
• WAL archive storage on a local PVC (Tier 1)
• Extension of base backup retention policy enforcement to WAL files
• Asynchronous WAL relay to Tier 2 object storage

note

Klio's WAL management utilizes the READ_REPLICATION_SLOT streaming replication command, which was introduced in PostgreSQL 15. Therefore, Klio requires PostgreSQL version 15 or greater to function properly.

Base Backup Catalog

• Physical online base backups from the primary node to Tier 1, with support for:
  • Data deduplication for efficient remote incremental backups
  • Encryption using user-provided keys for data confidentiality
• Backup catalog stored on a file system Persistent Volume Claim (PVC) in Tier 1
• Retention policy enforcement
• Asynchronous replication of base backups to Tier 2 object storage for long-term durability and disaster recovery

General Capabilities

• End-to-end encryption: both in-transit and at-rest
• Delivered as a CNPG-I plugin, with an accompanying Kubernetes Operator
• Distributed via a Helm chart for streamlined deployment