Kubeflow

This guide describes how to back up the Charmed Kubeflow (CKF) control plane data to a compatible S3 storage.

Requirements

• Access to a S3 storage used for the backup data.
• Admin access to the Kubernetes cluster where CKF is deployed.
• Juju admin access to the kubeflow model.
• yq binary.
• Ensure the local storage is big enough to back up the data.

Configure rclone

rclone is a tool that allows file management in cloud storage. This tool will be used for backing up several files throughout this guide and it can be installed as a snap:

sudo snap install rclone

Connect to a shared S3 storage

1. Configure rclone to connect to the shared S3 storage. The following can be used as reference:

[remote-s3]
type = s3
provider = AWS
env_auth = true
access_key_id = ...
secret_access_key = ...
region = eu-central-1
acl = private
server_side_encryption = AES256

2. Save the name of the S3 remote in an ENV variable:

RCLONE_S3_REMOTE=remote-s3

Connect to CKF MinIO

1. The following steps require an accessible MinIO endpoint, which can be done port forwarding the minio service:

kubectl port-forward -n kubeflow svc/minio 9000:9000

2. Get minio’s secret-key value:

juju show-unit kfp-ui/0 \
        | yq '.kfp-ui/0.relation-info.[] | select (.endpoint == "object-storage") | .application-data.data' \
        | yq '.secret-key'

3. Get minio’s access-key:

juju config minio access-key

4. Configure rclone to connect to CKF MinIO. The following can be used as reference:

[minio-ckf]
type = s3
provider = Minio
access_key_id = minio
secret_access_key = ...
endpoint = http://localhost:9000
acl = private

5. Save the name of the MinIO remote in an ENV variable:

RCLONE_MINIO_CKF_REMOTE=minio-ckf

Back up CKF databases to S3 storage

CKF uses katib-db and kfp-db as databases for Katib and Kubeflow pipelines respectively.

1. Deploy and configure the s3-integrator to connect to the shared S3 storage.

See S3 AWS and S3 Radowsg configuration guides for this step.

2. Scale up kfp-db and katib-db.

This step avoids the Primary database from becoming unavailable during backup.

juju scale-application kfp-db 2
juju scale-application katib-db 2

3. Create a backup for each database.

Replace mysql-k8s with the name of the database you intend to create a backup for in the commands from that guide.

Back up ML metadata using sqlite3

The mlmd charm uses a SQLite database to store ML metadata generated from Kubeflow pipelines.

1. Install the required tools inside the application container:

# MLMD > 1.14, CKF 1.9
MLMD_POD="mlmd-0"
MLMD_CONTAINER="mlmd-grpc-server"

# MLMD 1.14, CKF 1.8
MLMD_POD="mlmd-0"
MLMD_CONTAINER="mlmd"

kubectl exec -n kubeflow $MLMD_POD -c $MLMD_CONTAINER -- \
    /bin/bash -c "apt update && apt install sqlite3 -y"

2. Scale down kfp-metadata-writer. This is done to prevent any additional writes to mlmd.

juju scale-application kfp-metadata-writer 0

3. Perform a database backup.

This moves all the database contents into a compressed text file inside the mlmd-0 container:

MLMD_BACKUP=mlmd-$(date -d "today" +"%Y-%m-%d-%H-%M").dump.gz

kubectl exec -n kubeflow $MLMD_POD -c $MLMD_CONTAINER -- \
	/bin/bash -c \
	"sqlite3 /data/mlmd.db .dump | gzip -c >/tmp/$MLMD_BACKUP"

4. Copy the backup file to local storage:

kubectl cp -n kubeflow -c $MLMD_CONTAINER \
	$MLMD_POD:/tmp/$MLMD_BACKUP \
	./$MLMD_BACKUP

5. Copy the mlmd backup data to the S3 storage:

S3_BUCKET=backup-bucket-2024
RCLONE_S3_REMOTE=remote-s3
RCLONE_BWIDTH_LIMIT=20M

rclone --size-only copy \
	--bwlimit $RCLONE_BWIDTH_LIMIT \
	./$MLMD_BACKUP \
	$RCLONE_S3_REMOTE:$S3_BUCKET

Optionally, you can remove the mlmd data from your local machine:

rm -rf $MLMD_BACKUP

6. Scale up kfp-metadata-writer:

juju scale-application kfp-metadata-writer 1

Back up mlpipeline MinIO bucket

Sync all files from minio to the shared S3 storage:

S3_BUCKET=backup-bucket-2024
RCLONE_S3_REMOTE=remote-s3
RCLONE_BWIDTH_LIMIT=20M

rclone --size-only sync \
	--bwlimit $RCLONE_BWIDTH_LIMIT \
	$RCLONE_MINIO_REMOTE:mlpipeline \
	$RCLONE_S3_REMOTE:$S3_BUCKET/mlpipeline

Back up ML metadata with kubectl

You can also perform the backup using kubectl.

1. Scale down kfp-metadata-writer. This is done to prevent any additional writes to mlmd:

juju scale-application kfp-metadata-writer 0

2. Copy the backup file to local storage:

# MLMD > 1.14, CKF 1.9
MLMD_POD="mlmd-0"
MLMD_CONTAINER="mlmd-grpc-server"

# MLMD 1.14, CKF 1.8
MLMD_POD="mlmd-0"
MLMD_CONTAINER="mlmd"

kubectl cp -n kubeflow -c $MLMD_CONTAINER \
	$MLMD_POD:/data/mlmd.db \
	./$MLMD_BACKUP

3. Copy the mlmd backup data to the S3 storage:

S3_BUCKET=backup-bucket-2024
RCLONE_S3_REMOTE=remote-s3
RCLONE_BWIDTH_LIMIT=20M

rclone --size-only copy \
	--bwlimit $RCLONE_BWIDTH_LIMIT \
	./$MLMD_BACKUP \
	$RCLONE_S3_REMOTE:$S3_BUCKET

Optionally, you can remove the `mlmd’ backup data from your local machine:

rm -rf $MLMD_BACKUP

4. Scale up kfp-metadata-writer:

juju scale-application kfp-metadata-writer 1

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