Amazon Redshift
Database Developer Guide (API Version 2012-12-01)

Section 2: Modifying the WLM Query Queue Configuration

Now that you understand how queues work by default, you can learn how to configure query queues using manual WLM. In this section, you create and configure a new parameter group for your cluster. You create two additional user queues and configure them to accept queries based on the queries’ user group or query group labels. Any queries that don't get routed to one of these two queues are routed to the default queue at run time.

Step 1: Create a Parameter Group

In this step, you create a new parameter group to use to configure WLM for this tutorial.

To Create a Parameter Group

  1. Sign in to the AWS Management Console and open the Amazon Redshift console at

  2. In the navigation pane, choose Workload management.

  3. Choose Create parameter group.

  4. In the Create Cluster Parameter Group dialog box, enter wlmtutorial for Parameter group name and enter WLM tutorial for Description. You can leave the Parameter group family setting as is. Then choose Create.

Step 2: Configure WLM

In this step, you modify the default settings of your new parameter group. You add two new query queues to the WLM configuration and specify different settings for each queue.

To Modify Parameter Group Settings

  1. On the Parameter Groups page of the Amazon Redshift console, choose wlmtutorial. Doing this opens the Parameters page for wlmtutorial.

  2. Choose Switch WLM mode. On the WLM settings page, choose Manual WLM and Save.

  3. Choose the Workload Management tab. Choose Add queue twice to add two new queues to this WLM configuration. Configure the queues with the following values:

    • For queue 1, enter 2 for Concurrency on main, test for Query groups, and 30 for Memory (%). Leave the other settings with their default values.

    • For queue 2, enter 3 for Concurrency on main, admin for User groups, and 40 for Memory (%). Leave the other settings with their default values.

    • Don't make any changes to the Default queue. WLM assigns unallocated memory to the default queue.

  4. Choose Save.

Step 3: Associate the Parameter Group with Your Cluster

In this step, you open your sample cluster and associate it with the new parameter group. After you do this, you reboot the cluster so that Amazon Redshift can apply the new settings to the database.

To Associate the Parameter Group with Your Cluster

  1. In the navigation pane, choose Clusters, and then click your cluster to open it. If you are using the same cluster from Amazon Redshift Getting Started, your cluster is named examplecluster.

  2. On the Configuration tab, choose Modify for Cluster.

  3. In the Modify Cluster dialog box, choose wlmtutorial for Cluster Parameter Group, and then choose Modify.

    The statuses shown in the Cluster Parameter Group and Parameter Group Apply Status change from in-sync to applying as shown in the following.

    After the new parameter group is applied to the cluster, the Cluster Properties and Cluster Status show the new parameter group that you associated with the cluster. You need to reboot the cluster so that these settings can be applied to the database also.

  4. For Cluster, choose Reboot. The status shown in Cluster Status changes from available to rebooting. After the cluster is rebooted, the status returns to available.