Redis backup and restore in kubernetes

redis-backup-and-restore.md

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Case

1 - old redis in k8s cluster #1

2 - fresh install of redis in Cluster #2

• Target backup data in old cluster and restore in new cluster

Info:

• No auth configured
• command redis-cli BGSAVE - Save the DB in background.
• docker image https://hub.docker.com/r/bitnami/redis

Backup

1. Goto k8s cluster #1
2. Goto redis pod and create redis dump

 $ kubectl  exec -ti redis-0 -- bash
 $ redis-cli
 $> BGSAVE
 $> exit

3. Copy dump from pod to local

 $ kubectl cp redis-0:/bitnami/redis/data/dump.rdb $(pwd)/dump.rdb

4. Done with backup

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Restore

In cluster #2, new redis

1. Copy redis dump file to new redis pods

$ kubectl cp ./dump.rdb redis-0:/bitnami/redis/data/dump.rdb-1

2. Modify k8s resource deployment or statefullset and add new ENV Var

$ kubectl edit deployments.apps redis

containers:
  - env:
    - name: REDIS_AOF_ENABLED
      value: "no"
    - name: REDIS_DISABLE_COMMANDS
      value: FLUSHDB,FLUSHALL

• edit and save resource
• pod should restart

3. Restore redis dump

$ kubectl  exec -ti redis-0 -- bash
$ cd /bitnami/redis/data/
$ chmod 777 dump.rdb-1
$ cp dump.rdb-1 dump.rdb
$ redis-cli
$> bgrewriteaof     # start restoring
$> info             # find status of 'aof_rewrite_in_progress'
$> keys *           # find new keys
$> exit

4. Modify k8s resource deployment or statefullset and delete ENV Var - REDIS_AOF_ENABLED,REDIS_DISABLE_COMMANDS

$ kubectl edit deployments.apps redis

5. Wait for new pod and goto into and check if data restored

$ kubectl  exec -ti redis-0 -- bash
$ redis-cli
$> keys *           # find new keys

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