CHYT Update Guide

This document outlines how to update CHYT using the Kubernetes operator.

Important Information Before Updating

During a CHYT update:

• The YTsaurus cluster continues operating normally.
• YTsaurus server components aren’t restarted.
• Data access via the YTsaurus API remains available.
• CHYT clusters are temporarily unavailable.
• The update installs the new version alongside the current one without replacing it (Multiple CHYT Versions).
• Cliques automatically use the latest created resource with makeDefault: true as the default version.

Before updating:

1. Verify compatibility between CHYT, YTsaurus, and Strawberry versions.

   Refer to the compatibility table.

2. Ensure the strawberry controller is installed and configured — CHYT depends on it.

   Important

   Confirm that the strawberry controller is properly set up.

3. Review available CHYT versions and their changes.

   See the CHYT releases.

Preparation for the Update

1. Check the Current CHYT Version

Use the current CHYT specification to retrieve the version:

kubectl get chyt -n <namespace> -o yaml | grep image

Example output:

image: ghcr.io/ytsaurus/chyt:2.17.3

2. Check CHYT Status

Verify that CHYT is in the Finished state:

kubectl get chyt -n <namespace>

Example output:

NAME         STATUS
<chyt-name>  Finished

If CHYT isn’t in the Finished state, wait for ongoing operations to complete.

3. Save a Backup of the CHYT Specification

Save a backup of the current CHYT specification:

kubectl get chyt -n <namespace> -o yaml > chyt-backup.yaml

Updating CHYT

The operator doesn’t modify existing CHYT resources. Instead, it creates a new version as a separate resource.

1. Prepare the Specification for the New Version

Use the current CHYT specification as a basis:

kubectl get chyt <chyt-name> -n <namespace> -o yaml

Create a chyt-<new-version>.yaml file with:

• A new resource name in the metadata.name field.
• A new image version in the image field.
• makeDefault: true to set the new version as default for cliques.

Example specification for version 2.18.0:

apiVersion: cluster.ytsaurus.tech/v1
kind: Chyt
metadata:
  name: chyt-2-18-0
  namespace: <namespace>
spec:
  image: ghcr.io/ytsaurus/chyt:2.18.0
  makeDefault: true
  ytsaurus:
    name: <ytsaurus-name>

2. Apply the New Version

Apply the new version specification:

kubectl apply -f chyt-<new-version>.yaml -n <namespace>

The operator creates a new CHYT resource and uploads its artifacts to Cypress. The existing resource remains unchanged.

3. Track the Update Progress

Monitor the CHYT status during the update:

kubectl get chyt -n <namespace> -w

Update States:

4. Verify the Update

1. Confirm that both resources are in the Finished state:

   kubectl get chyt -n <namespace>
   

   Example output:

   NAME             STATUS
   <chyt-name>      Finished
   <new-chyt-name>  Finished
   

2. Check the new image version:

   kubectl get chyt -n <namespace> -o yaml | grep image
   

   Example output:

   image: ghcr.io/ytsaurus/chyt:2.18.0
   

Multiple CHYT Versions on a Single Cluster

The update process adds a new CHYT version as a separate resource, allowing multiple versions to coexist on the same YTsaurus cluster.

• Each version has its own image.
• Cliques use the latest resource with makeDefault: true as the default.
• You don’t need to modify the previous resource — it automatically loses default status.

Removing an Old CHYT Version

When the old CHYT version is no longer needed:

1. Delete the CHYT resource:

   kubectl delete chyt <old-chyt-name> -n <namespace>
   

2. Remove old artifacts from Cypress (if necessary):

   • Open the //sys/bin/ytserver-clickhouse and //sys/bin/clickhouse-trampoline directories.
   • Locate old version files by creation date.
   • Delete them from the context menu.