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>
This commit is contained in:
zeripath 2022-03-25 12:47:12 +00:00 committed by GitHub
parent e48f3b0527
commit 5fe764b1eb
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4 changed files with 55 additions and 48 deletions

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@ -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()
}

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@ -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)

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@ -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{})

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@ -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.