Canton Network MainNet v0.5.1 Major Upgrade Announcement And Advice

[Dave]

I want to inform everyone on the upcoming Canton Network MainNet major upgrade to Splice v0.5.1 / Canton v3.4 on December 10th, 2025. This is a major network upgrade and will cause network-wide downtime. Please familiarize yourself with the Splice documentation for rolling out major upgrades to ensure you are prepared for upgrading your validator node.

TestNet is performing the same major upgrade on November 26th. I strongly recommend that all wallet providers and exchanges participate in this network upgrade to practice the process ahead of the MainNet upgrade and gain some experience to ensure that the upgrade goes as smoothly as possible on MainNet. If you do not have a TestNet validator then please reach out to your Super Validator sponsor as soon as possible to get an IP whitelisted and a validator set up on TestNet so that you can participate in the upgrade.

The upgrade documentation in Splice focuses on the steps necessary for upgrading the validator node itself. Additional considerations apply for ensuring that your applications and integrations remain functional and consistent across major upgrades. Please read the Rolling out Major Splice Upgrades section of the Digital Asset Exchange Integration Guide to learn about the considerations and the runbook for exchange integrations to resume operations after the upgrade.

[bernhard]

Copying the announcement from Slack #validator-ops here.

PREPARING FOR THE MAJOR UPGRADE ON MAINNET DECEMBER 10THReminder that MainNet will go through a protocol-changing major upgrade on Wednesday, December 10th, starting at 9 am US Eastern (1400 UTC). Here are the most important things you need to know, and some recommendations on how to prepare.

• MainNet will pause and go offline at the start of the major upgrade

• MainNet will remain down between 3 and 6 hours

• This major upgrade with downtime was approved by a vote of the Super Validators to adopt CIP-0089

• Validators will stop processing transactions as soon as MainNet begins this pause.

• To rejoin the network and resume processing transactions, Validators must complete the migration steps outlined in the technical documentation for Major Upgrades, here:

  • https://docs.sync.global/validator_operator/validator_major_upgrades.html

• MainNet’s Migration ID will change as part of this upgrade. The Super Validators will announce the new Migration ID once MainNet comes back online. The default Migration_ID value will be 4, unless announced otherwise by the Super Validators.

• Every node should take a full backup of its node and identities before the upgrade. Details here:

  • https://docs.sync.global/validator_operator/validator_backups.html#backups

• Important Points:

  • Before initiating the upgrade procedure, Validators should confirm that their nodes do not have any Ledger API users without party-level permissions

    • See the example provided here:

      • https://github.com/global-synchronizer-foundation/docs/discussions/19#discussioncomment-15013845

  • Exchanges and other Application Providers should read closely through the additional guidance provided here:

    • https://docs.digitalasset.com/integrate/devnet/exchange-integration/node-operations.html#rolling-out-major-splice-upgrades

• The Super Validators strongly recommend that all node operators practice this major upgrade on TestNet: Wednesday, 26 November, starting at 9 am US Eastern. The following should consider the 26 November practice on TestNet to be mandatory:

  • Node as a Service providers

  • Wallet Providers

  • Application Providers

  • Exchanges