Configuring Dynamic Resource Pool
Admission control and dynamic resource pools are enabled by default. However, until you configure the settings for the dynamic resource pools, the admission control feature is effectively not enabled.
root.default. By default, all Impala queries run in
      this pool when the dynamic resource pool feature is enabled for Impala.
      You create additional pools when your workload includes identifiable
      groups of queries (such as from a particular application, or a particular
      group within your organization) that have their own requirements for
      concurrency, memory use, or service level agreement (SLA). Each pool has
      its own settings related to memory, number of queries, and timeout
      interval. 