Managing Impala Admission Control

Minimum Required Role: Configurator (also provided by Cluster Administrator, Full Administrator)

Admission control is an Impala feature that imposes limits on concurrent SQL queries, to avoid resource usage spikes and out-of-memory conditions on busy CDH clusters. It is a form of "throttling". New queries are accepted and executed until certain conditions are met, such as too many queries or too much total memory used across the cluster. When one of these thresholds is reached, incoming queries wait to begin execution. These queries are queued and are admitted (that is, begin executing) when the resources become available.

For further information on Impala admission control, see Admission Control and Query Queuing.

Enabling and Disabling Impala Admission Control Using Cloudera Manager

  1. Go to the Impala service.
  2. Click the Configuration tab.
  3. Expand the Service-Wide category.
  4. Click the Admission Control subcategory.
  5. Click the Enable Impala Admission Control property and check or uncheck the checkbox.
  6. Click Save Changes to commit the changes.
  7. Restart the Impala service.

Configuring Impala Admission Control Using Cloudera Manager

  1. Go to the Impala service.
  2. Click the Configuration tab.
  3. Expand the Service-Wide category.
  4. Click the Admission Control subcategory. Configure the properties described in Admission Control Options.
  5. Click Save Changes to commit the changes.
  6. Restart the Impala service.