Introduction

For businesses navigating the dynamic landscape of Kubernetes, safeguarding your data is critical. The 2+1 backup strategy offers a comprehensive approach to data protection, ensuring resilience, availability, and security within Kubernetes environments. This whitepaper delves into the 2+1 strategy, showcasing Open-Source solutions like Velero, Restic, and the Container Storage Interface (CSI).

In today’s fast-paced digital world, data safety issues such as accidental deletions, system failures, and cyber threats can have devastating impacts on your business. Implementing robust backup solutions is essential to prevent data loss and ensure business continuity. The 2+1 strategy ensures that your data is backed up in multiple locations, providing a safety net that protects against various failure scenarios and keeps your operations running smoothly.

The 2+1 Backup Strategy for Kubernetes

Understanding the 2+1 Strategy

The 2+1 backup strategy is designed to protect your business from data loss and ensure quick recovery. It works by keeping two backups on-site and one backup off-site. This approach creates multiple layers of protection, greatly reducing the risk of losing all your data and helping to ensure that your business can continue to operate smoothly even in the face of unforeseen issues.

Two On-Site Backups:

• Primary Backup – This backup is stored within the same Kubernetes cluster, allowing for quick access and fast recovery in case of minor data loss or corruption. It provides immediate availability for addressing issues as they arise.
• Secondary Backup – This backup is also on-site but saved on a different storage system within the cluster. It offers an additional layer of protection against localized failures or hardware malfunctions. Typically, a different backup method is used for this backup to enhance overall data security.

One Off-Site Backup:

• Off-Site Backup – This backup is kept in a remote location or secure cloud storage service. It safeguards your data against major disasters that could damage or destroy on-site backups, such as fire, floods, or other catastrophic events. This layer of protection ensures that your data remains secure and recoverable, no matter what happens to your primary and secondary backups.

Combining with retention periods

The 2+1 backup strategy is a vital framework for securing your data and maintaining business continuity in the cloud. In practice, on-site backups stored within your cloud environment ensure rapid recovery for minor issues and routine operations.

Additionally, defining appropriate retention periods for each backup is essential to maintaining data integrity and compliance. Retention periods ensure that backups are preserved for an adequate duration to meet regulatory requirements and recover from long-term issues. Implementing the 2+1 strategy with well-managed retention periods helps ensure your data remains secure, accessible, and recoverable, enabling uninterrupted business operations and resilience against potential disruptions.

Open-Source Solutions for Kubernetes Backups

There are several Open Source solutions available to help you implement a robust Kubernetes backup strategy. These solutions fall into two main categories:

1. General Backup Solutions – These offer broad backup capabilities for various storage systems and are suitable for general data protection needs across your Kubernetes environment.
2. Specialized Backup Solutions – These are tailored specifically for certain types of systems, such as databases like PostgreSQL. They provide more targeted backup and recovery options to address the unique requirements of these systems. This type of backup solution is a must have of any system providing critical solutions to internal or external customers.

Selecting the right type of solution depends on your specific backup needs and the systems you use within your Kubernetes environment. Next, we will dive into both categories and some examples.

General Back-up solutions

A general back-up solution is capable of creating a back-up for nearly any volume in Kubernetes. This is usually done at one of two levels; 1) at the volume or block level; and 2) at the filesystem level. Combining these two levels as part of your 2+1 back-up strategy offers good protection against corruption or data loss due to a wide range of reasons.

Storing the back-ups on different storage systems and/or cloud providers will also help you spread out risk and increase your disaster recovery capabilities. For this you could for example store filesystem back-ups in S3 buckets, while you would additionally create volume snapshots, providing you with two differently created back-ups.

There are several Open-Source solutions available to implement these strategies. In the following sections, we’ll explore some commonly used solutions within the Kubernetes ecosystem:

Velero & Restic

Velero is an Open-Source tool that provides backup, restore, and disaster recovery capabilities for Kubernetes clusters. It allows you to take snapshots of your entire cluster or specific namespaces and store them in a variety of locations, including cloud storage.

Features:

• Automated scheduled backups.
• Backup and restore of persistent volumes.
• Integration with cloud storage services like AWS, Azure, and Google Cloud.
• File System backup

Velero supports backing up and restoring Kubernetes volumes attached to pods from the file system of the volumes, called File System Backup (FSB shortly) or Pod Volume Backup. For this, Velero utilizes Restic - an Open-Source filesystem back-up solution. Additionally, Velero supports integration with CSI Volume Snapshots.

Container Storage Interface (CSI)

CSI is a standard for exposing storage systems to containerized workloads on Kubernetes. By leveraging CSI drivers, Kubernetes can interact with various storage systems, making it easier to manage backups across different storage solutions.

Features:

• Standardized interface for storage operations.
• Support for dynamic provisioning, snapshotting, and cloning of volumes.
• Compatibility with various storage providers.

By utilizing the CSI drivers using the CSI Volume Snapshot functionality, it is possible to quickly create raw disk snasphots that can be utilized for quick restore and recovery in minor incidents When creating a backup strategy with CSI VolumeSnapshots, you would commonly create a periodic snapshot (e.g. every hour, every day, etc), for which each have their own retention periods.

Fast restores

Depending on the Cloud platform used, snapshots are quickly available for restore purposes, and restores happen near instantly. For example, restoring an snapshot on AWS is ready for use within seconds or minutes (depending on the disk size). This makes snapshots ideal as an additional all-purpose backup solution for Kubernetes Persistent Volumes.

Limited Point-in-Time recovery

Since however Snapshots are created periodically, they do not support advanced point-in-time restore capabilities that allow you to restore to any point in time, including between two back-up points.

System specific backup solutions

In addition to general backup strategies, it is crucial to implement system-specific backup tooling for databases like PostgreSQL and MySQL. These tools are designed to address the unique requirements and intricacies of database management, ensuring data integrity, consistency, and recovery. Here’s a closer look at some of the most effective system-specific backup solutions for PostgreSQL and MySQL.

PostgreSQL Backup Solutions

pg_dump

pg_dump is a PostgreSQL utility for backing up a single database. It generates a logical backup, meaning it creates a set of SQL commands that can be used to recreate the database from scratch. It supports backing up entire databases or specific schemas and tables. You would use it in conjunction with cron jobs for scheduled backups.

pg_basebackup

pg_basebackup is a utility for taking physical backups of a PostgreSQL database cluster. It is particularly useful for setting up replication or creating a base backup for PITR (Point-in-Time Recovery). pg_basebackup allows full cluster backup, including configuration files and WAL segments. It offers simple command-line usage for easy integration into backup scripts.

Barman (Backup and Recovery Manager)

Barman is an Open-Source tool specifically designed for PostgreSQL backup and recovery. It simplifies the process of managing backups and ensures data safety through automated backup schedules and retention policies. Among it’s features are Support for both full and incremental backups, advanced Point-in-Time Recovery (PITR) capabilities. It utilizes pg_basebackup for creating the full-backup.

MySQL Backup Solutions

mysqldump

mysqldump is a command-line utility provided by MySQL for backing up databases. It produces a logical backup by creating SQL statements that can be used to recreate the original database.

Features:

• Capable of backing up entire databases or selected tables.
• Supports various output formats, including plain SQL and XML.
• Can be integrated into automated scripts for regular backups.

Implementing the 2+1 Strategy in Kubernetes

With a variety of backup solutions available, the next step is to integrate them into a cohesive and effective backup strategy for your Kubernetes environment.

Deploying your back-up solutions

When deploying your backup tooling and solutions, consider the following best practices:

Regular Scheduling

Automate backups using cron jobs or scheduling tools to ensure regular, consistent backups without manual intervention. Advanced backup solutions like Barman can be configured for streaming replication. Make sure you schedule periodic full backups of your systems to capture all data changes. Consistent scheduling helps to avoid data loss by creating regular snapshots of your data.

Data Consistency

Utilize tools that support consistent backups, such as pg_basebackup for PostgreSQL and Percona XtraBackup for MySQL, to avoid data corruption. Ensuring data consistency during backups is crucial to prevent corrupted data states, which could lead to failures in restoring data during disaster recovery. These tools ensure that the data captured is complete and reliable, even when backups are taken from live systems.

Automated Monitoring and Alerts

Implement monitoring and alerting systems to track backup status and receive notifications of any failures or issues. Tools like Prometheus and Alertmanager are effective for this purpose. By setting up automated monitoring, you can quickly detect and respond to issues, minimizing the risk of data loss. Alerts can be configured to notify your team immediately if a backup fails or if anomalies are detected.

Testing and Validation

Regularly test backup and restore processes to ensure data can be recovered accurately and quickly in the event of data loss. Conducting regular tests of your backup and restore processes ensures that your data recovery plan is effective and that your team is prepared to respond to real-world data loss scenarios. Testing helps identify potential issues before they impact your operations and validates that backups are complete and usable.

Storing Backups

When managing different types of backups and storage solutions, it’s important to consider more than just how the backups are made. Focus on ensuring that each backup method contributes to overall system security and reliability. This includes verifying that your data remains intact and protected from unauthorized access. Taking these factors into account helps maintain the integrity and safety of your entire system.

Local and Remote Storage

To ensure your data is fully protected, use both local and remote storage for your backups. Local storage provides quick access and fast recovery, which is ideal for day-to-day needs. Using high-speed storage for these local backups will help you restore data swiftly when needed.

Remote storage safeguards your data against major issues like site-specific failures or disasters. This means your data remains safe even if something goes wrong with your local infrastructure. By combining both types of storage, you balance quick recovery with strong protection against unexpected events.

Though be mindful of how bandwidth can affect your backup performance. Proper management ensures that backups are both efficient and effective, giving you peace of mind that your data is secure and easily recoverable.

Offsite Storage

To protect your data from disasters, store at least one backup copy offsite, such as in a different data center or with a cloud service like Amazon S3. This ensures your data remains safe from events like fires or floods at your primary site.

For added security, use versioned storage in S3 to keep multiple backup versions and manage cloud costs with tiered storage. Tools like rclone can help transfer backups to a remote S3 bucket, ensuring long-term and reliable backup storage.

Encryption and Security

To keep your backups safe, always use strong encryption to protect sensitive data. Make sure your encryption keys are stored securely, such as in a trusted system like Vault or a cloud provider’s key management service.

Encrypting your backups ensures that your data is protected from unauthorized access, maintaining its confidentiality and integrity. Proper key management is crucial to ensure only authorized individuals can access your backup data.