scheduler

Documentation

Index

• Constants
• type CmpBasedTaskComparator
  • func NewCmpBasedTaskComparator() *CmpBasedTaskComparator
  • func (self *CmpBasedTaskComparator) Len() int
  • func (self *CmpBasedTaskComparator) Less(i, j int) bool
  • func (self *CmpBasedTaskComparator) Swap(i, j int)
• type CmpBasedTaskPrioritizer
  • func (prioritizer *CmpBasedTaskPrioritizer) PrioritizeTasks(settings *evergreen.Settings, tasks []task.Task) ([]task.Task, error)
• type CmpBasedTaskQueues
• type DBTaskDurationEstimator
  • func (self *DBTaskDurationEstimator) GetExpectedDurations(runnableTasks []task.Task) (model.ProjectTaskDurations, error)
• type DBTaskFinder
  • func (self *DBTaskFinder) FindRunnableTasks() ([]task.Task, error)
• type DBTaskQueuePersister
  • func (self *DBTaskQueuePersister) PersistTaskQueue(distro string, tasks []task.Task, taskDurations model.ProjectTaskDurations) ([]model.TaskQueueItem, error)
• type DeficitBasedHostAllocator
  • func (self *DeficitBasedHostAllocator) NewHostsNeeded(hostAllocatorData HostAllocatorData, settings *evergreen.Settings) (map[string]int, error)
• type DistroScheduleData
• type DurationBasedHostAllocator
  • func (self *DurationBasedHostAllocator) NewHostsNeeded(hostAllocatorData HostAllocatorData, settings *evergreen.Settings) (newHostsNeeded map[string]int, err error)
• type HostAllocator
• type HostAllocatorData
• type Runner
  • func (r *Runner) Description() string
  • func (r *Runner) Name() string
  • func (r *Runner) Run(config *evergreen.Settings) error
• type ScheduledDistroTasksData
• type Scheduler
  • func (s *Scheduler) Schedule() error
• type TaskDurationEstimator
• type TaskFinder
• type TaskPrioritizer
• type TaskQueuePersister

Constants

const (
	// maximum turnaround we want to maintain for all hosts for a given distro
	MaxDurationPerDistroHost = time.Hour

	// for distro queues with tasks that appear on other queues, this constant
	// indicates the fraction of the total duration of shared tasks that we want
	// to account for when alternate distros are unable to satisfy the
	// turnaround requirement as determined by MaxDurationPerDistroHost
	SharedTasksAllocationProportion = 0.8
)

const (
	RunnerName  = "scheduler"
	Description = "queue tasks for execution and allocate hosts"
)

Types

type CmpBasedTaskComparator

type CmpBasedTaskComparator struct {
	// contains filtered or unexported fields
}

CmpBasedTaskComparator runs the tasks through a slice of comparator functions determining which is more important.

func NewCmpBasedTaskComparator

func NewCmpBasedTaskComparator() *CmpBasedTaskComparator

NewCmpBasedTaskComparator returns a new task prioritizer, using the default set of comparators as well as the setup functions necessary for those comparators.

func (*CmpBasedTaskComparator) Len

func (self *CmpBasedTaskComparator) Len() int

func (*CmpBasedTaskComparator) Less

func (self *CmpBasedTaskComparator) Less(i, j int) bool

func (*CmpBasedTaskComparator) Swap

func (self *CmpBasedTaskComparator) Swap(i, j int)

type CmpBasedTaskPrioritizer

type CmpBasedTaskPrioritizer struct{}

func (*CmpBasedTaskPrioritizer) PrioritizeTasks

func (prioritizer *CmpBasedTaskPrioritizer) PrioritizeTasks(
	settings *evergreen.Settings, tasks []task.Task) ([]task.Task, error)

PrioritizeTask prioritizes the tasks to run. First splits the tasks into slices based on whether they are part of patch versions or automatically created versions. Then prioritizes each slice, and merges them. Returns a full slice of the prioritized tasks, and an error if one occurs.

type CmpBasedTaskQueues

type CmpBasedTaskQueues struct {
	HighPriorityTasks []task.Task
	PatchTasks        []task.Task
	RepotrackerTasks  []task.Task
}

CmpBasedTaskQueues represents the three types of queues that are created for merging together into one queue. The HighPriorityTasks list represent the tasks that are always placed at the front of the queue PatchTasks and RepotrackerTasks are interleaved after the high priority tasks.

type DBTaskDurationEstimator

type DBTaskDurationEstimator struct{}

DBTaskDurationEstimator retrives the estimated duration of runnable tasks. Implements TaskDurationEstimator.

func (*DBTaskDurationEstimator) GetExpectedDurations

func (self *DBTaskDurationEstimator) GetExpectedDurations(
	runnableTasks []task.Task) (model.ProjectTaskDurations, error)

GetExpectedDurations returns the expected duration of tasks (by display name) on a project, buildvariant basis.

type DBTaskFinder

type DBTaskFinder struct{}

DBTaskFinder fetches tasks from the database. Implements TaskFinder.

func (*DBTaskFinder) FindRunnableTasks

func (self *DBTaskFinder) FindRunnableTasks() ([]task.Task, error)

FindRunnableTasks finds all tasks that are ready to be run. This works by fetching all undispatched tasks from the database, and filtering out any whose dependencies are not met.

type DBTaskQueuePersister

type DBTaskQueuePersister struct{}

DBTaskQueuePersister saves a queue to the database.

func (*DBTaskQueuePersister) PersistTaskQueue

func (self *DBTaskQueuePersister) PersistTaskQueue(distro string,
	tasks []task.Task,
	taskDurations model.ProjectTaskDurations) ([]model.TaskQueueItem, error)

PersistTaskQueue saves the task queue to the database. Returns an error if the db call returns an error.

type DeficitBasedHostAllocator

type DeficitBasedHostAllocator struct{}

DeficitBasedHostAllocator uses the difference between the number of free hosts and the number of tasks that need to be run as a metric for how many new hosts need to be spun up

func (*DeficitBasedHostAllocator) NewHostsNeeded

func (self *DeficitBasedHostAllocator) NewHostsNeeded(
	hostAllocatorData HostAllocatorData, settings *evergreen.Settings) (map[string]int, error)

NewHostsNeeded decides how many new hosts are needed for a distro by seeing if the number of tasks that need to be run for the distro is greater than the number of hosts currently free to run a task. Returns a map of distro-># of hosts to spawn.

type DistroScheduleData

type DistroScheduleData struct {
	// contains filtered or unexported fields
}

DistroScheduleData contains bookkeeping data that is used by distros to determine whether or not to allocate more hosts

type DurationBasedHostAllocator

type DurationBasedHostAllocator struct{}

DurationBasedHostAllocator computes the total time to completion of tasks running - per distro - and then uses that as a heuristic in determining how many new hosts to spin up

func (*DurationBasedHostAllocator) NewHostsNeeded

func (self *DurationBasedHostAllocator) NewHostsNeeded(
	hostAllocatorData HostAllocatorData, settings *evergreen.Settings) (newHostsNeeded map[string]int,
	err error)

NewHostsNeeded decides if new hosts are needed for a distro while taking the duration of running/scheduled tasks into consideration. Returns a map of distro to number of hosts to spawn.

type HostAllocator

type HostAllocator interface {
	NewHostsNeeded(allocatorData HostAllocatorData,
		settings *evergreen.Settings) (map[string]int, error)
}

HostAllocator is responsible for determining how many new hosts should be spun up. Parameters:

distros: a map of distro name -> information on that distro (a model.Distro object)
existingDistroHosts: a map of distro name -> currently running hosts on that distro
taskQueueItems: a map of distro name -> task queue items for that distro (a TaskQueue object)
projectTaskDurations: the expected duration of tasks by project and variant
taskRunDistros: a map of task id -> distros the task is allowed to run on

Returns a map of distro name -> how many hosts need to be spun up for that distro.

type HostAllocatorData

type HostAllocatorData struct {
	// contains filtered or unexported fields
}

HostAllocatorData is the set of parameters passed to a HostAllocator.

type Runner

type Runner struct{}

Runner runs the scheduler process.

func (*Runner) Description

func (r *Runner) Description() string

func (*Runner) Name

func (r *Runner) Name() string

func (*Runner) Run

func (r *Runner) Run(config *evergreen.Settings) error

type ScheduledDistroTasksData

type ScheduledDistroTasksData struct {
	// contains filtered or unexported fields
}

ScheduledDistroTasksData contains data that is used to compute the expected duration of tasks within a distro's queue

type Scheduler

type Scheduler struct {
	*evergreen.Settings
	TaskFinder
	TaskPrioritizer
	TaskDurationEstimator
	TaskQueuePersister
	HostAllocator
}

Responsible for prioritizing and scheduling tasks to be run, on a per-distro basis.

func (*Scheduler) Schedule

func (s *Scheduler) Schedule() error

Schedule all of the tasks to be run. Works by finding all of the tasks that are ready to be run, splitting them by distro, prioritizing them, and saving the per-distro queues. Then determines the number of new hosts to spin up for each distro, and spins them up.

type TaskDurationEstimator

type TaskDurationEstimator interface {
	GetExpectedDurations(runnableTasks []task.Task) (
		model.ProjectTaskDurations, error)
}

TaskDurationEstimator is responsible for fetching the expected duration for a given set of runnable tasks.

type TaskFinder

type TaskFinder interface {
	// Returns a slice of tasks that are ready to be run, and an error if
	// appropriate.
	FindRunnableTasks() ([]task.Task, error)
}

TaskFinder finds all tasks that are ready to be run.

type TaskPrioritizer

type TaskPrioritizer interface {
	// Takes in a slice of tasks and the current MCI settings.
	// Returns the slice of tasks, sorted in the order in which they should
	// be run, as well as an error if appropriate.
	PrioritizeTasks(settings *evergreen.Settings, tasks []task.Task) (
		[]task.Task, error)
}

TaskPrioritizer is responsible for taking in a slice of tasks, and ordering them according to which should be run first.

type TaskQueuePersister

type TaskQueuePersister interface {
	PersistTaskQueue(distro string, tasks []task.Task,
		taskExpectedDuration model.ProjectTaskDurations) ([]model.TaskQueueItem,
		error)
}

TaskQueuePersister is responsible for taking a task queue for a particular distro and saving it.