PP-587: Have only one mom report the compute node information to the server.

Overview:

This enhancement only applies to Cray systems.

In order to improve the performance of PBS on very large scale systems (20 K+ compute nodes), a number of changes were made to reduce

the time and CPU cycles required for the reporting of the list of compute nodes and resources (inventory) by the collective set of pbs_mom daemons

running on the system. The specific changes were mostly internal to PBS with the exception of the addition of a new node attribute (vnode_pool)

used to associate the inventory reported by a singe pbs_mom as applying to all pbs_moms on the same Cray system.

Interface #1: new node attribute: vnode_pool

Interface #2: new Mom log entry: "Hello (no inventory required) from server at <server address>"

Visibility: Public
Change Control: Experimental
Details:
- Comments on the Interface.
  - Interface standing: new interface.
  - Interface type: log message - log level: PBSEVENT_SYSTEM class PBS_EVENTCLASS_SERVER
- Recorded when Mom which is in a vnode_pool and not the 'Inventory' Mom is sent a Hello message by the Server.

Interface #3: new Server log entry: "invalid vnode_pool provided"

Interface #4: new Server log entry: "Unsupported actions for vnode_pool"

Interface #5: new Server log entry: "Error <#> setting attribute vnode_pool in update for vnode <name>"

Interface #6: new Server log entry: "POOL: IS_UPDATE<x> received"

Interface #7: new Server log entry: "write_single_node_mom_attr, Failed to update 'Mom' attribute"

Interface #8: new Server log entry: "Setting inventory_mom for vnode_pool <x> to <Mom name>"

Visibility: Public
Change Control: Experimental
Details:
- Comments on the interface:
  - Interface standing: new interface
  - Interface type: log message - log level: PBSEVENT_DEBUG
- Recorded when the inventory_mom is set (including each time the inventory_mom changes)

Interface #9: new Server log entry: "Mom <Mom name> added to vnode_pool <x>"

Visibility: Public
Change Control: Experimental
Details:
- Comments on the interface:
  - Interface standing: new interface
  - Interface type: log message - log level: PBSEVENT_DEBUG3
- Recorded when a mom is added to a vnode_pool

Interface #10: new Server log entry: "vnode_pool value is <x>"

Visibility: Public
Change Control: Experimental
Details:
- Comments on the interface:
  - Interface standing: new interface
  - Interface type: log message - log level: PBSEVENT_DEBUG3
- Recorded when a node is created or being recovered from the database

Interface #11: new Server log entry: "POOL: cross linking <x> vnodes from <mom>"

Visibility: Private
Change Control: Experimental
Details:
- Comments on the interface:
  - interface standing: new interface
  - Interface type: log message - log level: PBSEVENT_DEBUG4
- Recorded during mom creation when a mom is being added to a vnode_pool

Administrator's instructions.

Mixed versions of the PBS daemons cannot be run on the system. The pbs_server and all pbs_mom
daemons must be upgraded at once. An overlay upgrade is possible. The vnode_pool attribute should not be defined
in a vnode definition file. To do so will result in unspecified results. Specifying vnode_pool on a non Cray login node
is not recommended and will result in undefined behavior.

User's instructions and usage notes.