lotus/storage/sealer/sched_assigner_common.go
2022-06-14 20:03:38 +02:00

193 lines
5.0 KiB
Go

package sealer
import (
"context"
"math/rand"
"sort"
"sync"
)
type WindowSelector func(sh *Scheduler, queueLen int, acceptableWindows [][]int, windows []SchedWindow) int
// AssignerCommon is a task assigner with customizable parts
type AssignerCommon struct {
WindowSel WindowSelector
}
var _ Assigner = &AssignerCommon{}
func (a *AssignerCommon) TrySched(sh *Scheduler) {
/*
This assigns tasks to workers based on:
- Task priority (achieved by handling sh.SchedQueue in order, since it's already sorted by priority)
- Worker resource availability
- Task-specified worker preference (acceptableWindows array below sorted by this preference)
- Window request age
1. For each task in the SchedQueue find windows which can handle them
1.1. Create list of windows capable of handling a task
1.2. Sort windows according to task selector preferences
2. Going through SchedQueue again, assign task to first acceptable window
with resources available
3. Submit windows with scheduled tasks to workers
*/
windowsLen := len(sh.OpenWindows)
queueLen := sh.SchedQueue.Len()
log.Debugf("SCHED %d queued; %d open windows", queueLen, windowsLen)
if windowsLen == 0 || queueLen == 0 {
// nothing to schedule on
return
}
windows := make([]SchedWindow, windowsLen)
for i := range windows {
windows[i].Allocated = *NewActiveResources()
}
acceptableWindows := make([][]int, queueLen) // QueueIndex -> []OpenWindowIndex
// Step 1
throttle := make(chan struct{}, windowsLen)
var wg sync.WaitGroup
wg.Add(queueLen)
for i := 0; i < queueLen; i++ {
throttle <- struct{}{}
go func(sqi int) {
defer wg.Done()
defer func() {
<-throttle
}()
task := (*sh.SchedQueue)[sqi]
task.IndexHeap = sqi
var havePreferred bool
for wnd, windowRequest := range sh.OpenWindows {
worker, ok := sh.Workers[windowRequest.Worker]
if !ok {
log.Errorf("worker referenced by windowRequest not found (worker: %s)", windowRequest.Worker)
// TODO: How to move forward here?
continue
}
if !worker.Enabled {
log.Debugw("skipping disabled worker", "worker", windowRequest.Worker)
continue
}
needRes := worker.Info.Resources.ResourceSpec(task.Sector.ProofType, task.TaskType)
// TODO: allow bigger windows
if !windows[wnd].Allocated.CanHandleRequest(task.SealTask(), needRes, windowRequest.Worker, "schedAcceptable", worker.Info) {
continue
}
rpcCtx, cancel := context.WithTimeout(task.Ctx, SelectorTimeout)
ok, preferred, err := task.Sel.Ok(rpcCtx, task.TaskType, task.Sector.ProofType, worker)
cancel()
if err != nil {
log.Errorf("trySched(1) req.Sel.Ok error: %+v", err)
continue
}
if !ok {
continue
}
if havePreferred && !preferred {
// we have a way better worker for this task
continue
}
if preferred && !havePreferred {
// all workers we considered previously are much worse choice
acceptableWindows[sqi] = acceptableWindows[sqi][:0]
havePreferred = true
}
acceptableWindows[sqi] = append(acceptableWindows[sqi], wnd)
}
if len(acceptableWindows[sqi]) == 0 {
return
}
// Pick best worker (shuffle in case some workers are equally as good)
rand.Shuffle(len(acceptableWindows[sqi]), func(i, j int) {
acceptableWindows[sqi][i], acceptableWindows[sqi][j] = acceptableWindows[sqi][j], acceptableWindows[sqi][i] // nolint:scopelint
})
sort.SliceStable(acceptableWindows[sqi], func(i, j int) bool {
wii := sh.OpenWindows[acceptableWindows[sqi][i]].Worker // nolint:scopelint
wji := sh.OpenWindows[acceptableWindows[sqi][j]].Worker // nolint:scopelint
if wii == wji {
// for the same worker prefer older windows
return acceptableWindows[sqi][i] < acceptableWindows[sqi][j] // nolint:scopelint
}
wi := sh.Workers[wii]
wj := sh.Workers[wji]
rpcCtx, cancel := context.WithTimeout(task.Ctx, SelectorTimeout)
defer cancel()
r, err := task.Sel.Cmp(rpcCtx, task.TaskType, wi, wj)
if err != nil {
log.Errorf("selecting best worker: %s", err)
}
return r
})
}(i)
}
wg.Wait()
log.Debugf("SCHED windows: %+v", windows)
log.Debugf("SCHED Acceptable win: %+v", acceptableWindows)
// Step 2
scheduled := a.WindowSel(sh, queueLen, acceptableWindows, windows)
// Step 3
if scheduled == 0 {
return
}
scheduledWindows := map[int]struct{}{}
for wnd, window := range windows {
if len(window.Todo) == 0 {
// Nothing scheduled here, keep the window open
continue
}
scheduledWindows[wnd] = struct{}{}
window := window // copy
select {
case sh.OpenWindows[wnd].Done <- &window:
default:
log.Error("expected sh.OpenWindows[wnd].Done to be buffered")
}
}
// Rewrite sh.OpenWindows array, removing scheduled windows
newOpenWindows := make([]*SchedWindowRequest, 0, windowsLen-len(scheduledWindows))
for wnd, window := range sh.OpenWindows {
if _, scheduled := scheduledWindows[wnd]; scheduled {
// keep unscheduled windows open
continue
}
newOpenWindows = append(newOpenWindows, window)
}
sh.OpenWindows = newOpenWindows
}