> For the complete documentation index, see [llms.txt](https://docs.syntho.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.syntho.ai/deploy-syntho/deploy-syntho-using-kubernetes/upgrade.md).

# Upgrade

Use this page to upgrade a Kubernetes (Helm) deployment.

{% hint style="warning" %}
Back up your PostgreSQL metadata databases before upgrading. See [Back up PostgreSQL](/deploy-syntho/deploy-syntho-using-kubernetes/back-up-postgresql.md).
{% endhint %}

{% hint style="warning" %}
**Reconfigure Databricks authentication.**

Syntho no longer supports Databricks personal access tokens. The upgrade removes the stored tokens, so Databricks connections fail until you configure workload identity federation, or a service principal client secret on each connection. Configure it as described in [Databricks](/setup-workspaces/create-a-workspace/connect-to-a-database/databricks.md#authentication) before upgrading, then test each Databricks connection.
{% endhint %}

{% hint style="warning" %}
**Review throughput settings after upgrading.**

The migration resets every workspace `default_data_batch_size` to `500000`, including customized values. It initializes `default_parallel_writing` to `true` and drops `default_simultaneous_read_write`. Review tuned settings after upgrading.
{% endhint %}

{% stepper %}
{% step %}
**Update values**

* **Syntho License key upgrade**
  * In `helm/ray/values.yaml`
    * <pre class="language-yaml"><code class="lang-yaml"><strong>SynthoLicense: &#x3C;new-license-key>
      </strong></code></pre>
  * In `helm/syntho-ui/values.yaml`
    * <pre class="language-yaml"><code class="lang-yaml"><strong>SynthoLicense: &#x3C;new-license-key>
      </strong></code></pre>
* **Application version upgrade**
  * `helm/ray/values.yaml`
    * ```yaml
      ray-cluster:
        image:
          tag: <new-version-number>
      ```
  * `helm/syntho-ui/values.yaml`
    * ```yaml
      frontend:
        image:
          tag: <new-version-number>
      backend:
        image:
          tag: <new-version-number>
      core:
        image:
          tag: <new-version-number>
      ```

{% endstep %}

{% step %}
**Rotate ImagePullSecret (if registry credentials changed)**

```bash
kubectl delete secret syntho-cr-secret -n syntho
kubectl create secret docker-registry syntho-cr-secret \
  --namespace syntho \
  --docker-server=<REGISTRY_HOST> \
  --docker-username=<USERNAME> \
  --docker-password=<PASSWORD>
```

{% endstep %}

{% step %}
**Apply the upgrade**

```bash
helm upgrade ray-cluster ./helm/ray/chart \
  --values helm/ray/values.yaml \
  --namespace syntho

helm upgrade syntho-ui ./helm/syntho-ui \
  --values helm/syntho-ui/values.yaml \
  --namespace syntho
```

{% endstep %}

{% step %}
**Recreate the Ray head**

KubeRay doesn't recreate the Ray head when the Ray chart changes, so it keeps running the previous version until it is recreated. Recreating it stops running jobs, so do it when no jobs are running:

```bash
kubectl delete pod -n syntho -l ray.io/node-type=head
```

{% endstep %}

{% step %}
**Verify**

```bash
kubectl get pods -n syntho
kubectl get events -n syntho --sort-by=.lastTimestamp | tail -n 30
```

If pods are restarting:

```bash
kubectl logs -n syntho <pod-name>
```

{% endstep %}
{% endstepper %}

<details>

<summary>Ray CRDs (only for some upgrades)</summary>

Some Ray/KubeRay upgrades require CRD changes.

If Helm reports CRD-related errors, upgrade the CRDs first (or reinstall Ray following the guidance from Syntho Support).

</details>


---

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