org.apache.hadoop.yarn.api.records

Enum ReservationRequestInterpreter

java.lang.Object

java.lang.Enum<ReservationRequestInterpreter>

org.apache.hadoop.yarn.api.records.ReservationRequestInterpreter

All Implemented Interfaces:

Serializable, Comparable<ReservationRequestInterpreter>

@InterfaceAudience.Public
@InterfaceStability.Evolving
public enum ReservationRequestInterpreter
extends Enum<ReservationRequestInterpreter>

Enumeration of various types of dependencies among multiple ReservationRequests within one ReservationDefinition (from least constraining to most constraining).

Enum Constant Summary

Enum Constants

Enum Constant and Description
R_ALL Requires that ALL of the ReservationRequest submitted as part of a ReservationDefinition are satisfied for the overall ReservationDefinition to be satisfied.
R_ANY Requires that exactly ONE among the ReservationRequest submitted as of a ReservationDefinition is satisfied to satisfy the overall ReservationDefinition.
R_ORDER Requires that ALL of the ReservationRequest submitted as part of a ReservationDefinition are satisfied for the overall ReservationDefinition to be satisfied.
R_ORDER_NO_GAP Requires that ALL of the ReservationRequest submitted as part of a ReservationDefinition are satisfied for the overall ReservationDefinition to be satisfied.

Method Summary

Methods

Modifier and Type	Method and Description
static ReservationRequestInterpreter	valueOf(String name) Returns the enum constant of this type with the specified name.
static ReservationRequestInterpreter[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

R_ANY

public static final ReservationRequestInterpreter R_ANY

Requires that exactly ONE among the ReservationRequest submitted as of a ReservationDefinition is satisfied to satisfy the overall ReservationDefinition.

WHEN TO USE THIS: This is useful when the user have multiple equivalent ways to run an application, and wants to expose to the ReservationAgent such flexibility. For example an application could use one <32GB,16core> container for 10min, or 16 <2GB,1core> containers for 15min, the ReservationAgent will decide which one of the two it is best for the system to place.

R_ALL

public static final ReservationRequestInterpreter R_ALL

Requires that ALL of the ReservationRequest submitted as part of a ReservationDefinition are satisfied for the overall ReservationDefinition to be satisfied. No constraints are imposed on the temporal ordering of the allocation used to satisfy the ResourceRequests.

WHEN TO USE THIS: This is useful to capture a scenario in which the user cares for multiple ReservationDefinition to be all accepted, or none. For example, a user might want a reservation R1: with 10 x <8GB,4core> for 10min, and a reservation R2: with 2 <1GB,1core> for 1h, and only if both are satisfied the workflow run in this reservation succeeds. The key differentiator from ALL and ORDER, ORDER_NO_GAP, is that ALL imposes no restrictions on the relative allocations used to place R1 and R2 above.

R_ORDER

public static final ReservationRequestInterpreter R_ORDER

Requires that ALL of the ReservationRequest submitted as part of a ReservationDefinition are satisfied for the overall ReservationDefinition to be satisfied. Moreover, it imposes a strict temporal ordering on the allocation used to satisfy the ReservationRequests. The allocations satisfying the ReservationRequest in position k must strictly precede the allocations for the ReservationRequest at position k+1. No constraints are imposed on temporal gaps between subsequent allocations (the last instant of the previous allocation can be an arbitrary long period of time before the first instant of the subsequent allocation).

WHEN TO USE THIS: Like ALL this requires all ReservationDefinitions to be placed, but it also imposes a time ordering on the allocations used. This is important if the ReservationDefinition(s) are used to describe a workflow with inherent inter-stage dependencies. For example, a first job runs in a ReservaitonDefinition R1 (10 x <1GB,1core> for 20min), and its output is consumed by a second job described by a ReservationDefinition R2 (5 x <1GB,1core>) for 50min). R2 allocation cannot overlap R1, as R2 models a job depending on the output of the job modeled by R1.

R_ORDER_NO_GAP

public static final ReservationRequestInterpreter R_ORDER_NO_GAP

Requires that ALL of the ReservationRequest submitted as part of a ReservationDefinition are satisfied for the overall ReservationDefinition to be satisfied. Moreover, it imposes a strict temporal ordering on the allocation used to satisfy the ReservationRequests. It imposes a strict temporal ordering on the allocation used to satisfy the ReservationRequests. The allocations satisfying the ReservationRequest in position k must strictly precede the allocations for the ReservationRequest at position k+1. Moreover it imposes a "zero-size gap" between subsequent allocations, i.e., the last instant in time of the allocations associated with the ReservationRequest at position k must be exactly preceding the first instant in time of the ReservationRequest at position k+1. Time ranges are interpreted as [a,b) inclusive left, exclusive right. WHEN TO USE THIS: This is a stricter version of R_ORDER, which allows no gaps between the allocations that satisfy R1 and R2. The use of this is twofold: 1) prevent long gaps between subsequent stages that produce very large intermediate output (e.g., the output of R1 is too large to be kept around for long before the job running in R2 consumes it, and disposes of it), 2) if the job being modeled has a time-varying resource need, one can combine multiple ResourceDefinition each approximating a portion of the job execution (think of using multiple rectangular bounding boxes to described an arbitrarily shaped area). By asking for no-gaps we guarantee "continuity" of resources given to this job. This still allow for some flexibility, as the entire "train" of allocations can be moved rigidly back or forth within the start-deadline time range (if there is slack).

Method Detail

values

public static ReservationRequestInterpreter[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ReservationRequestInterpreter c : ReservationRequestInterpreter.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ReservationRequestInterpreter valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null