package sectorstorage import ( "context" "fmt" "math/rand" "sort" "sync" "time" "golang.org/x/xerrors" "github.com/filecoin-project/specs-actors/actors/abi" "github.com/filecoin-project/lotus/extern/sector-storage/sealtasks" "github.com/filecoin-project/lotus/extern/sector-storage/storiface" ) type schedPrioCtxKey int var SchedPriorityKey schedPrioCtxKey var DefaultSchedPriority = 0 var SelectorTimeout = 5 * time.Second var InitWait = 3 * time.Second var ( SchedWindows = 2 ) func getPriority(ctx context.Context) int { sp := ctx.Value(SchedPriorityKey) if p, ok := sp.(int); ok { return p } return DefaultSchedPriority } func WithPriority(ctx context.Context, priority int) context.Context { return context.WithValue(ctx, SchedPriorityKey, priority) } const mib = 1 << 20 type WorkerAction func(ctx context.Context, w Worker) error type WorkerSelector interface { Ok(ctx context.Context, task sealtasks.TaskType, spt abi.RegisteredSealProof, a *workerHandle) (bool, error) // true if worker is acceptable for performing a task Cmp(ctx context.Context, task sealtasks.TaskType, a, b *workerHandle) (bool, error) // true if a is preferred over b } type scheduler struct { spt abi.RegisteredSealProof workersLk sync.RWMutex nextWorker WorkerID workers map[WorkerID]*workerHandle newWorkers chan *workerHandle watchClosing chan WorkerID workerClosing chan WorkerID schedule chan *workerRequest windowRequests chan *schedWindowRequest // owned by the sh.runSched goroutine schedQueue *requestQueue openWindows []*schedWindowRequest info chan func(interface{}) closing chan struct{} closed chan struct{} testSync chan struct{} // used for testing } type workerHandle struct { w Worker info storiface.WorkerInfo preparing *activeResources active *activeResources lk sync.Mutex wndLk sync.Mutex activeWindows []*schedWindow // stats / tracking wt *workTracker // for sync manager goroutine closing cleanupStarted bool closedMgr chan struct{} closingMgr chan struct{} } type schedWindowRequest struct { worker WorkerID done chan *schedWindow } type schedWindow struct { allocated activeResources todo []*workerRequest } type activeResources struct { memUsedMin uint64 memUsedMax uint64 gpuUsed bool cpuUse uint64 cond *sync.Cond } type workerRequest struct { sector abi.SectorID taskType sealtasks.TaskType priority int // larger values more important sel WorkerSelector prepare WorkerAction work WorkerAction start time.Time index int // The index of the item in the heap. indexHeap int ret chan<- workerResponse ctx context.Context } type workerResponse struct { err error } func newScheduler(spt abi.RegisteredSealProof) *scheduler { return &scheduler{ spt: spt, nextWorker: 0, workers: map[WorkerID]*workerHandle{}, newWorkers: make(chan *workerHandle), watchClosing: make(chan WorkerID), workerClosing: make(chan WorkerID), schedule: make(chan *workerRequest), windowRequests: make(chan *schedWindowRequest, 20), schedQueue: &requestQueue{}, info: make(chan func(interface{})), closing: make(chan struct{}), closed: make(chan struct{}), } } func (sh *scheduler) Schedule(ctx context.Context, sector abi.SectorID, taskType sealtasks.TaskType, sel WorkerSelector, prepare WorkerAction, work WorkerAction) error { ret := make(chan workerResponse) select { case sh.schedule <- &workerRequest{ sector: sector, taskType: taskType, priority: getPriority(ctx), sel: sel, prepare: prepare, work: work, start: time.Now(), ret: ret, ctx: ctx, }: case <-sh.closing: return xerrors.New("closing") case <-ctx.Done(): return ctx.Err() } select { case resp := <-ret: return resp.err case <-sh.closing: return xerrors.New("closing") case <-ctx.Done(): return ctx.Err() } } func (r *workerRequest) respond(err error) { select { case r.ret <- workerResponse{err: err}: case <-r.ctx.Done(): log.Warnf("request got cancelled before we could respond") } } type SchedDiagRequestInfo struct { Sector abi.SectorID TaskType sealtasks.TaskType Priority int } type SchedDiagInfo struct { Requests []SchedDiagRequestInfo OpenWindows []WorkerID } func (sh *scheduler) runSched() { defer close(sh.closed) go sh.runWorkerWatcher() iw := time.After(InitWait) var initialised bool for { var doSched bool select { case w := <-sh.newWorkers: sh.newWorker(w) case wid := <-sh.workerClosing: sh.dropWorker(wid) case req := <-sh.schedule: sh.schedQueue.Push(req) doSched = true if sh.testSync != nil { sh.testSync <- struct{}{} } case req := <-sh.windowRequests: sh.openWindows = append(sh.openWindows, req) doSched = true case ireq := <-sh.info: ireq(sh.diag()) case <-iw: initialised = true iw = nil doSched = true case <-sh.closing: sh.schedClose() return } if doSched && initialised { // First gather any pending tasks, so we go through the scheduling loop // once for every added task loop: for { select { case req := <-sh.schedule: sh.schedQueue.Push(req) if sh.testSync != nil { sh.testSync <- struct{}{} } case req := <-sh.windowRequests: sh.openWindows = append(sh.openWindows, req) default: break loop } } sh.trySched() } } } func (sh *scheduler) diag() SchedDiagInfo { var out SchedDiagInfo for sqi := 0; sqi < sh.schedQueue.Len(); sqi++ { task := (*sh.schedQueue)[sqi] out.Requests = append(out.Requests, SchedDiagRequestInfo{ Sector: task.sector, TaskType: task.taskType, Priority: task.priority, }) } for _, window := range sh.openWindows { out.OpenWindows = append(out.OpenWindows, window.worker) } return out } func (sh *scheduler) trySched() { /* 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 */ windows := make([]schedWindow, len(sh.openWindows)) acceptableWindows := make([][]int, sh.schedQueue.Len()) log.Debugf("SCHED %d queued; %d open windows", sh.schedQueue.Len(), len(windows)) sh.workersLk.RLock() defer sh.workersLk.RUnlock() if len(sh.openWindows) == 0 { // nothing to schedule on return } // Step 1 concurrency := len(sh.openWindows) throttle := make(chan struct{}, concurrency) var wg sync.WaitGroup wg.Add(sh.schedQueue.Len()) for i := 0; i < sh.schedQueue.Len(); i++ { throttle <- struct{}{} go func(sqi int) { defer wg.Done() defer func() { <-throttle }() task := (*sh.schedQueue)[sqi] needRes := ResourceTable[task.taskType][sh.spt] task.indexHeap = sqi for wnd, windowRequest := range sh.openWindows { worker, ok := sh.workers[windowRequest.worker] if !ok { log.Errorf("worker referenced by windowRequest not found (worker: %d)", windowRequest.worker) // TODO: How to move forward here? continue } // TODO: allow bigger windows if !windows[wnd].allocated.canHandleRequest(needRes, windowRequest.worker, "schedAcceptable", worker.info.Resources) { continue } rpcCtx, cancel := context.WithTimeout(task.ctx, SelectorTimeout) ok, err := task.sel.Ok(rpcCtx, task.taskType, sh.spt, worker) cancel() if err != nil { log.Errorf("trySched(1) req.sel.Ok error: %+v", err) continue } if !ok { continue } 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.Error("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 := 0 for sqi := 0; sqi < sh.schedQueue.Len(); sqi++ { task := (*sh.schedQueue)[sqi] needRes := ResourceTable[task.taskType][sh.spt] selectedWindow := -1 for _, wnd := range acceptableWindows[task.indexHeap] { wid := sh.openWindows[wnd].worker wr := sh.workers[wid].info.Resources log.Debugf("SCHED try assign sqi:%d sector %d to window %d", sqi, task.sector.Number, wnd) // TODO: allow bigger windows if !windows[wnd].allocated.canHandleRequest(needRes, wid, "schedAssign", wr) { continue } log.Debugf("SCHED ASSIGNED sqi:%d sector %d task %s to window %d", sqi, task.sector.Number, task.taskType, wnd) windows[wnd].allocated.add(wr, needRes) // TODO: We probably want to re-sort acceptableWindows here based on new // workerHandle.utilization + windows[wnd].allocated.utilization (workerHandle.utilization is used in all // task selectors, but not in the same way, so need to figure out how to do that in a non-O(n^2 way), and // without additional network roundtrips (O(n^2) could be avoided by turning acceptableWindows.[] into heaps)) selectedWindow = wnd break } if selectedWindow < 0 { // all windows full continue } windows[selectedWindow].todo = append(windows[selectedWindow].todo, task) sh.schedQueue.Remove(sqi) sqi-- scheduled++ } // 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, len(sh.openWindows)-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 } func (sh *scheduler) runWorker(wid WorkerID) { var ready sync.WaitGroup ready.Add(1) defer ready.Wait() go func() { sh.workersLk.RLock() worker, found := sh.workers[wid] sh.workersLk.RUnlock() ready.Done() if !found { panic(fmt.Sprintf("worker %d not found", wid)) } defer close(worker.closedMgr) scheduledWindows := make(chan *schedWindow, SchedWindows) taskDone := make(chan struct{}, 1) windowsRequested := 0 ctx, cancel := context.WithCancel(context.TODO()) defer cancel() workerClosing, err := worker.w.Closing(ctx) if err != nil { return } defer func() { log.Warnw("Worker closing", "workerid", wid) // TODO: close / return all queued tasks }() for { // ask for more windows if we need them for ; windowsRequested < SchedWindows; windowsRequested++ { select { case sh.windowRequests <- &schedWindowRequest{ worker: wid, done: scheduledWindows, }: case <-sh.closing: return case <-workerClosing: return case <-worker.closingMgr: return } } select { case w := <-scheduledWindows: worker.wndLk.Lock() worker.activeWindows = append(worker.activeWindows, w) worker.wndLk.Unlock() case <-taskDone: log.Debugw("task done", "workerid", wid) case <-sh.closing: return case <-workerClosing: return case <-worker.closingMgr: return } sh.workersLk.RLock() worker.wndLk.Lock() windowsRequested -= sh.workerCompactWindows(worker, wid) assignLoop: // process windows in order for len(worker.activeWindows) > 0 { firstWindow := worker.activeWindows[0] // process tasks within a window, preferring tasks at lower indexes for len(firstWindow.todo) > 0 { tidx := -1 worker.lk.Lock() for t, todo := range firstWindow.todo { needRes := ResourceTable[todo.taskType][sh.spt] if worker.preparing.canHandleRequest(needRes, wid, "startPreparing", worker.info.Resources) { tidx = t break } } worker.lk.Unlock() if tidx == -1 { break assignLoop } todo := firstWindow.todo[tidx] log.Debugf("assign worker sector %d", todo.sector.Number) err := sh.assignWorker(taskDone, wid, worker, todo) if err != nil { log.Error("assignWorker error: %+v", err) go todo.respond(xerrors.Errorf("assignWorker error: %w", err)) } // Note: we're not freeing window.allocated resources here very much on purpose copy(firstWindow.todo[tidx:], firstWindow.todo[tidx+1:]) firstWindow.todo[len(firstWindow.todo)-1] = nil firstWindow.todo = firstWindow.todo[:len(firstWindow.todo)-1] } copy(worker.activeWindows, worker.activeWindows[1:]) worker.activeWindows[len(worker.activeWindows)-1] = nil worker.activeWindows = worker.activeWindows[:len(worker.activeWindows)-1] windowsRequested-- } worker.wndLk.Unlock() sh.workersLk.RUnlock() } }() } func (sh *scheduler) workerCompactWindows(worker *workerHandle, wid WorkerID) int { // move tasks from older windows to newer windows if older windows // still can fit them if len(worker.activeWindows) > 1 { for wi, window := range worker.activeWindows[1:] { lower := worker.activeWindows[wi] var moved []int for ti, todo := range window.todo { needRes := ResourceTable[todo.taskType][sh.spt] if !lower.allocated.canHandleRequest(needRes, wid, "compactWindows", worker.info.Resources) { continue } moved = append(moved, ti) lower.todo = append(lower.todo, todo) lower.allocated.add(worker.info.Resources, needRes) window.allocated.free(worker.info.Resources, needRes) } if len(moved) > 0 { newTodo := make([]*workerRequest, 0, len(window.todo)-len(moved)) for i, t := range window.todo { if len(moved) > 0 && moved[0] == i { moved = moved[1:] continue } newTodo = append(newTodo, t) } window.todo = newTodo } } } var compacted int var newWindows []*schedWindow for _, window := range worker.activeWindows { if len(window.todo) == 0 { compacted++ continue } newWindows = append(newWindows, window) } worker.activeWindows = newWindows return compacted } func (sh *scheduler) assignWorker(taskDone chan struct{}, wid WorkerID, w *workerHandle, req *workerRequest) error { needRes := ResourceTable[req.taskType][sh.spt] w.lk.Lock() w.preparing.add(w.info.Resources, needRes) w.lk.Unlock() go func() { err := req.prepare(req.ctx, w.wt.worker(w.w)) sh.workersLk.Lock() if err != nil { w.lk.Lock() w.preparing.free(w.info.Resources, needRes) w.lk.Unlock() sh.workersLk.Unlock() select { case taskDone <- struct{}{}: case <-sh.closing: log.Warnf("scheduler closed while sending response (prepare error: %+v)", err) } select { case req.ret <- workerResponse{err: err}: case <-req.ctx.Done(): log.Warnf("request got cancelled before we could respond (prepare error: %+v)", err) case <-sh.closing: log.Warnf("scheduler closed while sending response (prepare error: %+v)", err) } return } err = w.active.withResources(wid, w.info.Resources, needRes, &sh.workersLk, func() error { w.lk.Lock() w.preparing.free(w.info.Resources, needRes) w.lk.Unlock() sh.workersLk.Unlock() defer sh.workersLk.Lock() // we MUST return locked from this function select { case taskDone <- struct{}{}: case <-sh.closing: } err = req.work(req.ctx, w.wt.worker(w.w)) select { case req.ret <- workerResponse{err: err}: case <-req.ctx.Done(): log.Warnf("request got cancelled before we could respond") case <-sh.closing: log.Warnf("scheduler closed while sending response") } return nil }) sh.workersLk.Unlock() // This error should always be nil, since nothing is setting it, but just to be safe: if err != nil { log.Errorf("error executing worker (withResources): %+v", err) } }() return nil } func (sh *scheduler) newWorker(w *workerHandle) { w.closedMgr = make(chan struct{}) w.closingMgr = make(chan struct{}) sh.workersLk.Lock() id := sh.nextWorker sh.workers[id] = w sh.nextWorker++ sh.workersLk.Unlock() sh.runWorker(id) select { case sh.watchClosing <- id: case <-sh.closing: return } } func (sh *scheduler) dropWorker(wid WorkerID) { sh.workersLk.Lock() defer sh.workersLk.Unlock() w := sh.workers[wid] sh.workerCleanup(wid, w) delete(sh.workers, wid) } func (sh *scheduler) workerCleanup(wid WorkerID, w *workerHandle) { select { case <-w.closingMgr: default: close(w.closingMgr) } sh.workersLk.Unlock() select { case <-w.closedMgr: case <-time.After(time.Second): log.Errorf("timeout closing worker manager goroutine %d", wid) } sh.workersLk.Lock() if !w.cleanupStarted { w.cleanupStarted = true newWindows := make([]*schedWindowRequest, 0, len(sh.openWindows)) for _, window := range sh.openWindows { if window.worker != wid { newWindows = append(newWindows, window) } } sh.openWindows = newWindows log.Debugf("dropWorker %d", wid) go func() { if err := w.w.Close(); err != nil { log.Warnf("closing worker %d: %+v", err) } }() } } func (sh *scheduler) schedClose() { sh.workersLk.Lock() defer sh.workersLk.Unlock() log.Debugf("closing scheduler") for i, w := range sh.workers { sh.workerCleanup(i, w) } } func (sh *scheduler) Info(ctx context.Context) (interface{}, error) { ch := make(chan interface{}, 1) sh.info <- func(res interface{}) { ch <- res } select { case res := <-ch: return res, nil case <-ctx.Done(): return nil, ctx.Err() } } func (sh *scheduler) Close(ctx context.Context) error { close(sh.closing) select { case <-sh.closed: case <-ctx.Done(): return ctx.Err() } return nil }