--- title: Basic upgrade --- This guide discusses how to upgrade Deephaven on one or more hosts. If your deployment uses Kubernetes, please refer to the [Kubernetes upgrade guide](../kubernetes/kubernetes-upgrade-guide.md). If your deployment uses Podman, consult the [Podman upgrade guide](./podman-upgrade.md). ## Before you upgrade > [!CAUTION] > Take a complete backup before upgrading. If the upgrade causes a critical issue, restoring from a pre-upgrade backup is your only supported recovery path. Downgrading by switching binaries without restoring from backup is not supported and may result in data corruption or an unrecoverable state. See [Backup and restoration](../backup-restore-migrate/backup-and-restore.md) for backup instructions, and [Reverting an upgrade](../backup-restore-migrate/backup-and-restore.md#reverting-an-upgrade) for the implications of reverting after an upgrade. When possible, test the upgrade process in a development or staging environment before applying it to production systems. ## Upgrading to Grizzly+ Carefully review the [list of breaking changes](../../reference/release-notes/rn-202601.md#breaking-changes) before upgrading to Grizzly+. These include: - The [removal of Java 11, legacy Python 3.9, and Ubuntu 20.04 support](../../reference/release-notes/rn-202601.md#removed-features). - Changes to the [handling of NULL and NaN](../../reference/release-notes/rn-202601.md#data-behavior-changes). - The need to [regenerate your loggers](../../reference/release-notes/rn-202601.md#api-changes). TLS certificate handling changed significantly in Grizzly+. Review the [TLS certificates](../security/tls-certificates.md) and [Native installation TLS certificate requirements](./basic-install.md#tls-certificates) documentation before upgrading. - Native installations now use [one certificate per machine](../security/tls-certificates.md#one-certificate-per-machine). Rather than supply a single `tls.crt` and `tls.key` for all machines, instead place one `.pem` and `.key` pair per machine in [`DH_LOCAL_CERT_DIR`](cluster-config-guide.md#dh_local_cert_dir). - The use of an explicit truststore file is now [optional and off by default](../security/tls-certificates.md#optional-truststore). If you choose to limit the scope of trusted TLS certificate through a truststore file, you must supply your [CA certificate bundle](../admin-glossary.md#certificate-authority-ca) via [`DH_CA_CERTIFICATE`](cluster-config-guide.md#dh_ca_certificate). - Generated keystores and truststores are always overwritten. On upgrades and certificate rotation, Deephaven [overwrites derived keystores and truststores](../security/tls-certificates.md#certificates-are-always-overwritten). If you previously modified files under `/etc/sysconfig/deephaven/{auth,auth-user,trust}` directly, you must instead supply those certificates to the installer. For complete details on all breaking changes and new features, see the [Grizzly+ release notes](../../reference/release-notes/rn-202601.md). As always, read the [release notes](../../reference/release-notes/rn-202601.md) and [version logs](../../reference/version-logs/vl-202601.md) for any releases being skipped during this upgrade. If upgrading from [Vermilion+](/enterprise/vplus/docs/reference/release-notes/rn-20231218/) or earlier releases, review the release notes and version logs for all intermediate releases. Deephaven recommends the following before upgrading to Grizzly Plus. - **Backup your data**: Always ensure you have a complete backup of your data and configuration before upgrading. - **Test in a non-production environment**: When possible, test the upgrade process in a development or staging environment before upgrading production systems. ## Upgrade process To upgrade Deephaven to a newer version, update [DH_VERSION](./cluster-config-guide.md#dh_version) to the desired version and re-run the process in the [basic install](./basic-install.md) document, replacing the installation media during the [installation node setup](./basic-install.md#prepare-the-installer-host). ## Related documentation - [Installation planning](./installation-planning.md) - [Basic install](./basic-install.md)