Job

Jobs in ElastiSim have a designated type that defines (1) whether the job supports reconfigurations (i.e., resource modifications during runtime) and (2) the responsible entity initiating the request. Reconfiguration requests are either initiated by the scheduler or the job itself. While jobs must accept reconfiguration requests initiated by the scheduler, the scheduler can decline those initiated by jobs (so-called evolving requests).

In addition to rigid, moldable, malleable, and evolving jobs, ElastiSim supports a fifth job type, introduced as adaptive jobs, combining the features of malleable and evolving jobs. The following table describes the job types with their corresponding characteristics:

Type	Number of resources	Reconfigurable during runtime	Accepts reconfiguration requests	Can request reconfigurations
Rigid	Fixed	No	-	-
Moldable	Variable	No	-	-
Malleable	Variable	Yes	Yes	No
Evolving	Variable	Yes	No	Yes
Adaptive	Variable	Yes	Yes	Yes

Each job holds properties that the scheduling algorithm can use to make scheduling decisions. Users can specify the following properties using the JSON format:

Property	Description	Value type	Default value	Mandatory
jobs	Array of all jobs (top-level structure)	array	-	Yes
type	Job type ("rigid", "moldable", "malleable", "evolving", or "adaptive")	string	-	Yes
submit_time	Submission time of the job (absolute value)	float (seconds)	-	Yes
application_model	Application model of the job (path to file)	string	-	Yes
walltime	Time limit of a job before it is killed (0 for no limit)	float (seconds)	0	No
arguments	Custom arguments (i.e., variables) used in performance models	map	empty map	No
attributes	Custom attributes forwarded to the scheduler (e.g., priority)	map	empty map	No

As rigid jobs have a fixed number of resources, they require the number of nodes or GPUs, respectively:

Property	Description	Value type	Default value	Mandatory
num_nodes	Requested number of nodes	integer	-	Yes
num_gpus_per_node	Requested number of GPUs per node	integer	0	No

Jobs make requests based on compute nodes, not CPUs or CPU cores, respectively.

Moldable, malleable, evolving and adaptive jobs have a variable number of resources, specified using the following properties:

Property	Description	Value type	Default value	Mandatory
num_nodes_min	Requested number of nodes (minimum)	integer	-	Yes
num_nodes_max	Requested number of nodes (maximum)	integer	-	Yes
num_gpus_per_node_min	Requested number of GPUs per node (minimum)	integer	0	No
num_gpus_per_node_max	Requested number of GPUs per node (maximum)	integer	0	No

ElastiSim allows minimum and maximum values to be the same (e.g., malleable jobs requesting a fixed number of GPUs per node).

Example job file

{
  "jobs": [
    {
      "type": "rigid",
      "submit_time": 0,
      "num_nodes": 12,
      "num_gpus_per_node": 4,
      "application_model": "/path/to/application_model_1.json",
      "arguments": {
        "x": 20,
        "y": 60.8
      },
      "attributes": {
        "priority": 50
      }
    },
    {
      "type": "rigid",
      "submit_time": 80,
      "num_nodes": 12,
      "application_model": "/path/to/application_model_2.json",
      "arguments": {
        "alpha": 15
      },
      "attributes": {
        "priority": 0
      }
    },
    {
      "type": "evolving",
      "submit_time": 120,
      "num_nodes_min": 8,
      "num_nodes_max": 24,
      "application_model": "/path/to/application_model_3.json",
      "attributes": {
        "priority": 40
      }
    },
    {
      "type": "malleable",
      "submit_time": 360,
      "num_nodes_min": 12,
      "num_nodes_max": 36,
      "application_model": "/path/to/application_model_3.json",
      "arguments": {
        "beta": 80.4
      },
      "attributes": {
        "name": "special_job",
        "priority": 110
      }
    },
    {
      "type": "adaptive",
      "submit_time": 480,
      "num_nodes_min": 10,
      "num_nodes_max": 20,
      "num_gpus_per_node_min": 2,
      "num_gpus_per_node_max": 4,
      "application_model": "/path/to/application_model_4.json",
      "arguments": {
        "gamma": 14.7
      },
      "attributes": {
        "name": "special_job_2",
        "dependency": "special_job",
        "priority": 30
      }
    },
    {
      "type": "moldable",
      "submit_time": 420,
      "num_nodes_min": 16,
      "num_nodes_max": 32,
      "num_gpus_per_node_min": 4,
      "num_gpus_per_node_max": 4,
      "application_model": "/path/to/application_model_5.json",
      "attributes": {
        "priority": 140
      }
    }
  ]
}