Verifying instance groups

After creating an instance group, you may want to verify that all is well with the instance group. You can also verify the resource distribution plan to check how resources are allocated to consumers associated with the instance group.

1. From the cluster management console, select Workload > Instance Groups.
   In the instance group list, you can view a summary of each instance group; for example, its state, cores and memory used.

   Tip:

   • In an instance group with Spark and other instance group components (such as notebooks with CPUs or GPUs, and Dask), the resource usage information (hosts, slots, cores, CPU or GPU memory usage) on the Instance Group List tab are reflective of services for Spark applications, not the other components. For example, a dash (-) as the column value for Cores used in the Instance Group List tab indicates no Spark applications are using cores; it does not mean that no cores are used.

     You can apply IBM® Spectrum Conductor interim fix 600176 so that the information is reflective of all components.

   • Cores show only for services of a regular instance group, not for those running in Docker containers.
2. Click an instance group to view detailed information.
   • In the Overview tab, look for messages indicating next steps or problems with the instance group. In the Resource usage section, click the Slot-based or Multidimensional resource plan links to review consumer resource allocation. If the instance group is deployed, in the Spark deployment section, click the deployed timestamp link to check deployment details.
     Tip: In an instance group with Spark and other components (such as notebooks with CPUs or GPUs, and Dask), the resource usage information (hosts, slots, cores, CPU or GPU memory usage) on the Overview tab are reflective of services for Spark applications, not the other instance group components. For example, a message about GPU allocation not enabled on the Overview tab indicates no Spark applications are using GPUs; it does not mean that no GPUs are used.

     You can apply IBM Spectrum Conductor interim fix 600176 so that the information is reflective of all components.

   • In the Services tab, review the state of the services created by the instance group. You can also review details of instances for each service.
3. If you want to modify settings for the instance group, select Configure from the Manage list.