Add pprof labels in processes and for lifecycles (#19202) Use pprof labelling to help identify goroutines with stacks. Signed-off-by: Andrew Thornton <art27@cantab.net>

Changes

4 changed files (+55/-48)

• modules/graceful/manager.go
  • @@ -6,6 +6,7 @@ package graceful
    import ( "context" + "runtime/pprof" "sync" "time"
  • @@ -62,7 +63,6 @@ type WithCallback func(callback func())
    // Similarly the callback function provided to atTerminate must return once termination is complete. // Please note that use of the atShutdown and atTerminate callbacks will create go-routines that will wait till their respective signals // - users must therefore be careful to only call these as necessary. - // If run is not expected to run indefinitely RunWithShutdownChan is likely to be more appropriate. type RunnableWithShutdownFns func(atShutdown, atTerminate func(func())) // RunWithShutdownFns takes a function that has both atShutdown and atTerminate callbacks
  • @@ -70,7 +70,6 @@ type RunnableWithShutdownFns func(atShutdown, atTerminate func(func()))
    // Similarly the callback function provided to atTerminate must return once termination is complete. // Please note that use of the atShutdown and atTerminate callbacks will create go-routines that will wait till their respective signals // - users must therefore be careful to only call these as necessary. - // If run is not expected to run indefinitely RunWithShutdownChan is likely to be more appropriate. func (g *Manager) RunWithShutdownFns(run RunnableWithShutdownFns) { g.runningServerWaitGroup.Add(1) defer g.runningServerWaitGroup.Done()
  • @@ -98,32 +97,6 @@ func (g *Manager) RunWithShutdownFns(run RunnableWithShutdownFns) {
    }) } - // RunnableWithShutdownChan is a runnable with functions to run at shutdown and terminate. - // After the atShutdown channel is closed, the main function must return once shutdown is complete. - // (Optionally IsHammer may be waited for instead however, this should be avoided if possible.) - // The callback function provided to atTerminate must return once termination is complete. - // Please note that use of the atTerminate function will create a go-routine that will wait till terminate - users must therefore be careful to only call this as necessary. - type RunnableWithShutdownChan func(atShutdown <-chan struct{}, atTerminate WithCallback) - - // RunWithShutdownChan takes a function that has channel to watch for shutdown and atTerminate callbacks - // After the atShutdown channel is closed, the main function must return once shutdown is complete. - // (Optionally IsHammer may be waited for instead however, this should be avoided if possible.) - // The callback function provided to atTerminate must return once termination is complete. - // Please note that use of the atTerminate function will create a go-routine that will wait till terminate - users must therefore be careful to only call this as necessary. - func (g *Manager) RunWithShutdownChan(run RunnableWithShutdownChan) { - g.runningServerWaitGroup.Add(1) - defer g.runningServerWaitGroup.Done() - defer func() { - if err := recover(); err != nil { - log.Critical("PANIC during RunWithShutdownChan: %v\nStacktrace: %s", err, log.Stack(2)) - g.doShutdown() - } - }() - run(g.IsShutdown(), func(atTerminate func()) { - g.RunAtTerminate(atTerminate) - }) - } - // RunWithShutdownContext takes a function that has a context to watch for shutdown. // After the provided context is Done(), the main function must return once shutdown is complete. // (Optionally the HammerContext may be obtained and waited for however, this should be avoided if possible.)
  • @@ -136,7 +109,9 @@ func (g *Manager) RunWithShutdownContext(run func(context.Context)) {
    g.doShutdown() } }() - run(g.ShutdownContext()) + ctx := g.ShutdownContext() + pprof.SetGoroutineLabels(ctx) // We don't have a label to restore back to but I think this is fine + run(ctx) } // RunAtTerminate adds to the terminate wait group and creates a go-routine to run the provided function at termination
  • @@ -198,6 +173,8 @@ func (g *Manager) doShutdown() {
    } g.lock.Lock() g.shutdownCtxCancel() + atShutdownCtx := pprof.WithLabels(g.hammerCtx, pprof.Labels("graceful-lifecycle", "post-shutdown")) + pprof.SetGoroutineLabels(atShutdownCtx) for _, fn := range g.toRunAtShutdown { go fn() }
  • @@ -214,7 +191,7 @@ func (g *Manager) doShutdown() {
    g.doTerminate() g.WaitForTerminate() g.lock.Lock() - g.doneCtxCancel() + g.managerCtxCancel() g.lock.Unlock() }() }
  • @@ -227,6 +204,8 @@ func (g *Manager) doHammerTime(d time.Duration) {
    default: log.Warn("Setting Hammer condition") g.hammerCtxCancel() + atHammerCtx := pprof.WithLabels(g.terminateCtx, pprof.Labels("graceful-lifecycle", "post-hammer")) + pprof.SetGoroutineLabels(atHammerCtx) for _, fn := range g.toRunAtHammer { go fn() }
  • @@ -244,6 +223,9 @@ func (g *Manager) doTerminate() {
    default: log.Warn("Terminating") g.terminateCtxCancel() + atTerminateCtx := pprof.WithLabels(g.managerCtx, pprof.Labels("graceful-lifecycle", "post-terminate")) + pprof.SetGoroutineLabels(atTerminateCtx) + for _, fn := range g.toRunAtTerminate { go fn() }
  • @@ -331,20 +313,20 @@ func (g *Manager) InformCleanup() {
    // Done allows the manager to be viewed as a context.Context, it returns a channel that is closed when the server is finished terminating func (g *Manager) Done() <-chan struct{} { - return g.doneCtx.Done() + return g.managerCtx.Done() } // Err allows the manager to be viewed as a context.Context done at Terminate func (g *Manager) Err() error { - return g.doneCtx.Err() + return g.managerCtx.Err() } // Value allows the manager to be viewed as a context.Context done at Terminate func (g *Manager) Value(key interface{}) interface{} { - return g.doneCtx.Value(key) + return g.managerCtx.Value(key) } // Deadline returns nil as there is no fixed Deadline for the manager, it allows the manager to be viewed as a context.Context func (g *Manager) Deadline() (deadline time.Time, ok bool) { - return g.doneCtx.Deadline() + return g.managerCtx.Deadline() }
• modules/graceful/manager_unix.go
  • @@ -12,6 +12,7 @@ import (
    "errors" "os" "os/signal" + "runtime/pprof" "sync" "syscall" "time"
  • @@ -29,11 +30,11 @@ type Manager struct {
    shutdownCtx context.Context hammerCtx context.Context terminateCtx context.Context - doneCtx context.Context + managerCtx context.Context shutdownCtxCancel context.CancelFunc hammerCtxCancel context.CancelFunc terminateCtxCancel context.CancelFunc - doneCtxCancel context.CancelFunc + managerCtxCancel context.CancelFunc runningServerWaitGroup sync.WaitGroup createServerWaitGroup sync.WaitGroup terminateWaitGroup sync.WaitGroup
  • @@ -58,7 +59,17 @@ func (g *Manager) start(ctx context.Context) {
    g.terminateCtx, g.terminateCtxCancel = context.WithCancel(ctx) g.shutdownCtx, g.shutdownCtxCancel = context.WithCancel(ctx) g.hammerCtx, g.hammerCtxCancel = context.WithCancel(ctx) - g.doneCtx, g.doneCtxCancel = context.WithCancel(ctx) + g.managerCtx, g.managerCtxCancel = context.WithCancel(ctx) + + // Next add pprof labels to these contexts + g.terminateCtx = pprof.WithLabels(g.terminateCtx, pprof.Labels("graceful-lifecycle", "with-terminate")) + g.shutdownCtx = pprof.WithLabels(g.shutdownCtx, pprof.Labels("graceful-lifecycle", "with-shutdown")) + g.hammerCtx = pprof.WithLabels(g.hammerCtx, pprof.Labels("graceful-lifecycle", "with-hammer")) + g.managerCtx = pprof.WithLabels(g.managerCtx, pprof.Labels("graceful-lifecycle", "with-manager")) + + // Now label this and all goroutines created by this goroutine with the graceful-lifecycle manager + pprof.SetGoroutineLabels(g.managerCtx) + defer pprof.SetGoroutineLabels(ctx) // Set the running state & handle signals g.setState(stateRunning)
• modules/graceful/manager_windows.go
  • @@ -11,6 +11,7 @@ package graceful
    import ( "context" "os" + "runtime/pprof" "strconv" "sync" "time"
  • @@ -40,11 +41,11 @@ type Manager struct {
    shutdownCtx context.Context hammerCtx context.Context terminateCtx context.Context - doneCtx context.Context + managerCtx context.Context shutdownCtxCancel context.CancelFunc hammerCtxCancel context.CancelFunc terminateCtxCancel context.CancelFunc - doneCtxCancel context.CancelFunc + managerCtxCancel context.CancelFunc runningServerWaitGroup sync.WaitGroup createServerWaitGroup sync.WaitGroup terminateWaitGroup sync.WaitGroup
  • @@ -71,7 +72,17 @@ func (g *Manager) start() {
    g.terminateCtx, g.terminateCtxCancel = context.WithCancel(g.ctx) g.shutdownCtx, g.shutdownCtxCancel = context.WithCancel(g.ctx) g.hammerCtx, g.hammerCtxCancel = context.WithCancel(g.ctx) - g.doneCtx, g.doneCtxCancel = context.WithCancel(g.ctx) + g.managerCtx, g.managerCtxCancel = context.WithCancel(g.ctx) + + // Next add pprof labels to these contexts + g.terminateCtx = pprof.WithLabels(g.terminateCtx, pprof.Labels("graceful-lifecycle", "with-terminate")) + g.shutdownCtx = pprof.WithLabels(g.shutdownCtx, pprof.Labels("graceful-lifecycle", "with-shutdown")) + g.hammerCtx = pprof.WithLabels(g.hammerCtx, pprof.Labels("graceful-lifecycle", "with-hammer")) + g.managerCtx = pprof.WithLabels(g.managerCtx, pprof.Labels("graceful-lifecycle", "with-manager")) + + // Now label this and all goroutines created by this goroutine with the graceful-lifecycle manager + pprof.SetGoroutineLabels(g.managerCtx) + defer pprof.SetGoroutineLabels(g.ctx) // Make channels g.shutdownRequested = make(chan struct{})
• modules/process/manager.go
  • @@ -11,6 +11,7 @@ import (
    "fmt" "io" "os/exec" + "runtime/pprof" "sort" "strconv" "sync"
  • @@ -66,11 +67,9 @@ func GetManager() *Manager {
    // Most processes will not need to use the cancel function but there will be cases whereby you want to cancel the process but not immediately remove it from the // process table. func (pm *Manager) AddContext(parent context.Context, description string) (ctx context.Context, cancel context.CancelFunc, finished FinishedFunc) { - parentPID := GetParentPID(parent) - ctx, cancel = context.WithCancel(parent) - pid, finished := pm.Add(parentPID, description, cancel) + ctx, pid, finished := pm.Add(ctx, description, cancel) return &Context{ Context: ctx,
  • @@ -87,11 +86,9 @@ func (pm *Manager) AddContext(parent context.Context, description string) (ctx c
    // Most processes will not need to use the cancel function but there will be cases whereby you want to cancel the process but not immediately remove it from the // process table. func (pm *Manager) AddContextTimeout(parent context.Context, timeout time.Duration, description string) (ctx context.Context, cancel context.CancelFunc, finshed FinishedFunc) { - parentPID := GetParentPID(parent) - ctx, cancel = context.WithTimeout(parent, timeout) - pid, finshed := pm.Add(parentPID, description, cancel) + ctx, pid, finshed := pm.Add(ctx, description, cancel) return &Context{ Context: ctx,
  • @@ -100,7 +97,9 @@ func (pm *Manager) AddContextTimeout(parent context.Context, timeout time.Durati
    } // Add create a new process - func (pm *Manager) Add(parentPID IDType, description string, cancel context.CancelFunc) (IDType, FinishedFunc) { + func (pm *Manager) Add(ctx context.Context, description string, cancel context.CancelFunc) (context.Context, IDType, FinishedFunc) { + parentPID := GetParentPID(ctx) + pm.mutex.Lock() start, pid := pm.nextPID()
  • @@ -120,6 +119,7 @@ func (pm *Manager) Add(parentPID IDType, description string, cancel context.Canc
    finished := func() { cancel() pm.remove(process) + pprof.SetGoroutineLabels(ctx) } if parent != nil {
  • @@ -128,7 +128,10 @@ func (pm *Manager) Add(parentPID IDType, description string, cancel context.Canc
    pm.processes[pid] = process pm.mutex.Unlock() - return pid, finished + pprofCtx := pprof.WithLabels(ctx, pprof.Labels("process-description", description, "ppid", string(parentPID), "pid", string(pid))) + pprof.SetGoroutineLabels(pprofCtx) + + return pprofCtx, pid, finished } // nextPID will return the next available PID. pm.mutex should already be locked.