Zero Downtime Backups

Packaging an application
1

Replicated provides a way to achieve zero downtime backups by combining two of our more powerful replicated features: Admin Commands and Snapshots.

In this example we will demonstrate how to backup redis without having to stop the redis process itself:

Step 1: Create Redis Container with 2 volumes.

Note: This YAML creates 2 Docker volumes: 1) A primary volume (“data”) 2) a secondary volume (“backup”) that will be used to store the redis dump. Make sure that your primary volume (ie “data”) has is_excluded_from_backup: true to ensure that it isn’t paused during the backup process.

components:
- name: DB
  containers:
  - source: public
    image_name: redis
    version: latest
    cmd: "[\"redis-server\", \"--appendonly\", \"yes\"]"
    volumes:
    - host_path: /data
      container_path: /data:rw
      is_excluded_from_backup: true
    - host_path: /backup
      container_path: /backup
    support_files: []

Step 2: Create your admin Commands to backup and move data

admin_commands:
- alias: backup-redis-to-rdb
  command: [redis-cli, bgsave]
  run_type: exec
  component: DB
  container: redis
- alias: mv-backup-rdb-to-safe-place
  command: [mv, /data/dump.rdb, /backup/dump.rdb]
  run_type: exec
  component: DB
  container: redis

Step 3: Enable backups

We enable backups and inline a script that calls our admin commands (notice that we use the --no-tty flag). Note: pause_all is set to false thus enabling 0 downtime backups!

backup:
  enabled: true
  pause_all: false
  script: |
    #!/bin/sh
    replicated admin --no-tty backup-redis-to-rdb
    replicated admin --no-tty mv-backup-rdb-to-safe-place

And there you have it, zero downtime backup!

Download Full Replicated YAML Example.