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Configuring Impala catalog high availability

By default, the Impala Virtual Warehouse runs a single instance of the catalog. The catalog stores databases, tables, resource usage information, configuration settings, and other objects managed by Impala. You can optionally configure running an additional Impala catalog instance. One catalog instance operates in active mode, the other in passive mode. The passive instance serves as a backup and takes over if the active instance goes down.

You enable catalog high availability when you create a New Virtual Warehouse. You cannot turn on, but you can turn off catalog high availability after creating an Impala Virtual Warehouse.

When you create an Impala Virtual Warehouse, you use the same UI dropdown to configure Impala coordinator, covered in the previous topic, and Database Catalog high availability. You can choose one of the following options:
  • Disabled

    Disables Impala coordinator and Database Catalog high availability

  • Active-passive

    Runs multiple coordinators (one active, one passive) and Database Catalogs (one active, one passive)

  • Active-active coordinators

    Runs multiple coordinators (both active) and Database Catalogs (one active, one passive)

You must obtain the DWAdmin role.
  1. Follow instructions for Adding a new Virtual Warehouse.
  2. In Size, select the number of executors, for example xsmall-2Executors.
    A number of additional options appear, including High availability.
  3. In High availability (HA), accept the default Enabled (Active-Passive) or Enabled (Active-Active).
    Either option enables Database Catalog high availability in active-passive mode.
  4. Accept default values for other settings, or change the values to suit your use case.
    Click the tooltip for information about settings.
  5. Click Create Virtual Warehouse.