[HADOOP-17486] Provide fallbacks for callqueue ipc namespace properties

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.1.4
• Component/s: common
• Assignee: Unassigned
• Reporter: Jim Brennan
• Created: 21/Jan/21 20:16
• Updated: 21/Jan/21 20:16

Description

Filing this proposal on behalf of daryn, based on comments he made in one of our internal Jiras.

The following settings are currently specified per port:

  /**
   * CallQueue related settings. These are not used directly, but rather
   * combined with a namespace and port. For instance:
   * IPC_NAMESPACE + ".8020." + IPC_CALLQUEUE_IMPL_KEY
   */
  public static final String IPC_NAMESPACE = "ipc";
  public static final String IPC_CALLQUEUE_IMPL_KEY = "callqueue.impl";
  public static final String IPC_SCHEDULER_IMPL_KEY = "scheduler.impl";
  public static final String IPC_IDENTITY_PROVIDER_KEY = "identity-provider.impl";
  public static final String IPC_COST_PROVIDER_KEY = "cost-provider.impl";
  public static final String IPC_BACKOFF_ENABLE = "backoff.enable";
  public static final boolean IPC_BACKOFF_ENABLE_DEFAULT = false;
 

If one of these properties is not specified for the port, the defaults are hard-coded.
It would be nice to provide a way to specify a fallback default property that would be used for all ports. If the property for a specific port is not defined, the fallback would be used, and if the fallback is not defined it would use the hard-coded defaults.

We would likely need to make the same change for properties specified by these classes. For example, properties used in WeightedTimeCostProvider.

The fallback properties could be specified by dropping the port from the property name. For example, the fallback for ipc.8020.cost-provider.impl would be ipc.cost-provider.impl.
Another option would be to use something more explicit like ipc.default.cost-provider.impl.

Sub-Tasks

• Provide fallbacks for callqueue.impl and scheduler.impl: Resolved
• Provide fallbacks for identity/cost providers and backoff enable: Resolved