Hologres allows you to update Hologres instances in standard mode or hot update mode. This topic describes the two modes and the information required to update Hologres instances in each mode.

Background information

Hologres is backward compatible. Major version upgrades involve new features whereas minor version updates involve issue fixes. We recommend that you update your Hologres instances to the latest version.

Update modes

Update mode Update duration Instance status Impact on tasks Scenario Description
Standard mode 5 to 10 minutes Instances stop providing services when they are being updated.
  • Fully-managed Flink and DataHub tasks that involve data writes to Hologres must be stopped during instance updates and restarted after the updates are complete. Otherwise, data may be lost.
  • DataWorks data integration tasks and Blink tasks do not need to be stopped. During updates, failover is triggered and data is automatically restored based on the configured failover policy. We recommend that you set the number of failover retries to more than 10.
  • Minor version updates,

    such as an update from V0.10.25 to V0.10.36.

  • Major version upgrades,

    such as an upgrade from V0.10 to V1.1.

You must submit a ticket to contact the Hologres O&M personnel. The upgrades do not change the endpoints of the instances, but the IP addresses of the endpoints may change.
Hot update mode 10 to 30 minutes Instances are read-only when they are being updated. You can query data from the instances, but cannot write data to the instances. Hot update is supported only for Hologres V1.1 and later. You must submit a ticket to contact the Hologres O&M personnel. The updates do not change the endpoints of the instances, but the IP addresses of the endpoints may change.
Note We recommend that you pause real-time synchronization tasks during updates and restart them after the updates.

Information required for updates

You must provide required information when you submit a ticket to update Hologres instances. Different information is required in the following scenarios:

  • Minor version updates

    Pre-update instance checks are not required for minor version updates. Instances can be directly updated. In this scenario, you must provide your instance ID and the time window for the update in your ticket.

  • Major version upgrades
    Pre-update instance checks are required for major version upgrades. In this scenario, you must provide the information described in the following table in your ticket.
    Information Description
    Username The name of your Alibaba Cloud account or RAM user.
    Instance ID The ID of the Hologres instance that you want to update. You can query the instance ID on the Configurations tab of the instance details page in the Hologres console. For more information, see Instance configurations.
    Region ID The ID of the region in which the Hologres instance resides. You can query the region ID on the Configurations tab of the instance details page in the Hologres console. For more information, see Instance configurations.
    Instance version The current version of the Hologres instance. You can query the instance version on the Configurations tab of the instance details page in the Hologres console. For more information, see Instance configurations.
    Real-time writing
    • If you use a Blink or Flink engine to write data in real time, provide the version number of the engine.
      Note If the version of the engine is outdated, data may be lost during the updates. To prevent data loss, use Blink V3.7.9 or later, or Flink V3.0 or later.
    • If you use DataWorks to write data in real time, provide the real-time sync log and the region in which the resource group resides. If you use multiple exclusive resource groups for Data Integration, you must provide a log for each resource group.
    Expected update time The point in time at which you want the Hologres instance to start the update.
    Note
    • To ensure compatibility between different versions and retain the custom values of parameters, a pre-update check is required for the instance. The check window is one to three days before the update. Wait for the O&M personnel to inform you of the specific update time.
    • The instance stops providing services when it is being updated. The duration of an update varies based on the version and instance type of the instance. The update may take up to 20 minutes to complete.