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Comment: Addressed jon and sam's comments

Forum discussion link :http://community.pbspro.org/t/external-design-document-for-pp-824-cray-ramp-rate-limiting/693

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  • Interface 1: Changes to Power hook.
    • Change control: Stable
    • Synopsis: Power hook PBS_power
    • Details: Enabling/disabling pbshook PBS_power will enable/disable power management feature.
      • Through qmgr changing hook attribute "enabled" would enable or disable the hook and power management feature.
      • This hook will use server periodic event to ramp up/down and power on/off nodes.
      • Example:
        • qmgr -c "s pbshook PBS_power enabled=true"
        • qmgr -c "s pbshook PBS_power enabled=false"
  • Interface 2: Hook configuration file 
    • Change Control: Stable
    • Synopsis: JSON hook config file
    • Details: The configuration file allows the administrator to set global parameters, which are used to modify the behavior of the PBS_power hook across all nodes in the PBS Pro complex. The file must conform to JSON syntax. A sample configuration file is displayed and described below:

      {

      "power_ramp_rate_enable": "True",

      "power_on_off_enable": "False",

      "node_idle_limit": "1000",

      "min_powernode_down_delay": "600",

      "max_jobs_per_queue_limit": "80"

      }

    • Parameters:

Parameter Name

Default value

Description

power_ramp_rate_enableFalse

Enabling would make PBS perform ramp rate limiting across the PBS cluster running on a CRAY CLE 6.0 platform.

Nodes will be ramped-up and kept at sleep state C1 and for ramp down nodes will be put to sleep state C6.

power_on_off_enableFalse

Enabling would make PBS power on and off nodes on the nodes where node attribute poweroff_eligible is true.

node_idle_limit1800How long any node should be left idle before it to be considered for powering down or ramp down.
min_powernode_down_delay1800The time limit before a powered-off node can be considered to be brought up.
max_jobs_per_queue_limit100Queue level limit indicating maximum number of queued jobs that are analyzed for power on/ramp-up in each queue.
max_concurrent_power_limitnodes10Defines how many nodes can be power on/off or ramped up/down at a time.
  • Interface 3: New node attribute: poweroff_eligible
    • Change control: Stable
    • Synopsis: Node attribute for power control.
    • Details: This new node attribute will control if a node can be allowed to power off or not.
      • PBS type: Boolean
      • Python type: Boolean
      • Default value: False
      • Manager has set permission. All have read permission.
      • To modify the default value use qmgr:
        • qmgr -c "set node <node_name> poweroff_eligible=True"
  • Interface 4: New node attribute: last_state_change_time
    • Change control: Stable
    • Synopsis: Read only node attribute to capture timestamp.
    • Details: This new node attribute will be updated with time stamp when the node changes from its current state to a new state.
      • Managers and Operators have read permission.
      • Node status command pbsnodes will convert internal date format (seconds since epoch) to human readable format and display the value of this attribute in “MON DD YY HH:MM:SS” format.
      • PBS type: long
      • Python type: int
  • Interface 5: New node attribute: last_used_time
    • Change Control: Stable
    • Synopsis: Read only node attribute to capture timestamp.
    • Details: This new node attribute will be updated with time stamp at the end of any job or reservation.
      • If node is released early from a running job this timestamp gets updated.
      • Node status command pbsnodes will convert internal date format (seconds since epoch) to human readable format and display the value of this attribute in "MON DD YY HH:MM:SS" format.
      • Attribute will be reset when node is ramped up.
      • Managers and Operators have read permission.
      • For vnodes this attribute will be updated for the first time with the current timestamp when they are created or when the nodes are rebooted.
      • This attribute can now be used in sched_config as a node_sort_key. This will help sort the nodes based on their last used time.
      • PBS type: long
      • Python type: int
      • Example:
        • node_sort_key: "last_used_time HIGH"
        • node_sort_key: "last_used_time LOW"
  • Interface 6: New node state: sleep
    • Change Control: Stable
    • Synopsis: New node state that shows node is put down by PBS.
    • Details: This new node state will be set when nodes are ramped down or powered-off by PBS via power ramp rate limiting or power on/off feature.
      • A server periodic hook (pbs hook PBS_power provided as part of PBS package) runs every $freq seconds and takes list of vnodes to power ramp down/power-off the nodes and marks them in new sleep node state.
      • At most max_concurrent_power_limit nodes will be ramped down/powered-off every freq seconds, freq being the server periodic hook frequency.
      • Scheduler can consider the nodes in sleep state to run jobs now.
      • Server periodic hook can ramp-up/power-on the nodes which are in sleep state based on the requirement. Requirement is calculated based on analyzing the jobs estimated start time and the exec_vnode list.

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