Enabling exclusive slots at the allocation level

An exclusive policy uses all free slots from a host, and each host is assigned to only one allocation. To enable this type of allocation policy, use the cluster management console to configure for each resource group in your resource plan. Configure on your management hosts.

Before you begin

Before enabling exclusive slots, note the following interactions between this type of policy and other IBM® Spectrum Symphony features:
  • The exclusive slot allocation policy at both the allocation and consumer levels, is not compatible with MaxInstancesPerHost and MaxInstancesPerSlot configuration, which specifies the number of slots provided on each host. If MaxInstancesPerHost and MaxInstancesPerSlot is configured in the EGO service profile, the service cannot use a resource group configured for the exclusive slot policy. If you continue to use both configurations together, the EGO service will not start because of the conflicting combined configurations.
  • The exclusive slot allocation policy at both the allocation and consumer levels, is not compatible with the rusage feature, which limits the number of service instances applications can run on a host.

About this task

By default, an exclusive policy uses exclusive slots at the allocation level (that is, each host is assigned to only one allocation). This topic covers allocation-level exclusive slots. Alternatively , you can enable exclusive slots at the consumer level (where free slots from the host can be shared and assigned to any number of allocations, but only amongst a select set of consumers within an exclusive consumer group). To use exclusive slots at the consumer level, refer to Configuring exclusive slots at the consumer level instead.

Procedure

  1. From the cluster management console Dashboard, click Resources > Resource Planning (Slot) > Resource Plan.
  2. Select the ManagementHosts resource group.

    You are prompted that the ManagementHost resource group is for reserved use only.

  3. Click OK.
  4. Select exclusive slot allocation:
    • Expand Slot allocation policy and click Exclusive.
    • If you have EGO_ENABLE_CONSUMER_LEVEL_EXCLUSIVE=Y set in your ego.conf file, click Exclusive > Allocation level.

    An information message displays to indicate that the slot allocation policy will not affect any system services that have already been started. Only system services that are started from this moment on will be allocated using exclusive slot allocation.

  5. Click OK.
  6. Click Apply to save your changes.