Improve queue & process & stacktrace (#24636)

Although some features are mixed together in this PR, this PR is not
that large, and these features are all related.

Actually there are more than 70 lines are for a toy "test queue", so
this PR is quite simple.

Major features:

1. Allow site admin to clear a queue (remove all items in a queue)
* Because there is no transaction, the "unique queue" could be corrupted
in rare cases, that's unfixable.
* eg: the item is in the "set" but not in the "list", so the item would
never be able to be pushed into the queue.
* Now site admin could simply clear the queue, then everything becomes
correct, the lost items could be re-pushed into queue by future
operations.
3. Split the "admin/monitor" to separate pages
4. Allow to download diagnosis report
* In history, there were many users reporting that Gitea queue gets
stuck, or Gitea's CPU is 100%
    * With diagnosis report, maintainers could know what happens clearly

The diagnosis report sample:
[gitea-diagnosis-20230510-192913.zip](https://github.com/go-gitea/gitea/files/11441346/gitea-diagnosis-20230510-192913.zip)
, use "go tool pprof profile.dat" to view the report.


Screenshots:


![image](https://github.com/go-gitea/gitea/assets/2114189/320659b4-2eda-4def-8dc0-5ea08d578063)


![image](https://github.com/go-gitea/gitea/assets/2114189/c5c46fae-9dc0-44ca-8cd3-57beedc5035e)


![image](https://github.com/go-gitea/gitea/assets/2114189/6168a811-42a1-4e64-a263-0617a6c8c4fe)

---------

Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: Giteabot <teabot@gitea.io>

20 files changed, 387 insertions, 228 deletions

diff --git a/modules/queue/base_channel.go b/modules/queue/base_channel.go
index 27055faf4b..d03c72bdae 100644
--- a/modules/queue/base_channel.go
+++ b/modules/queue/base_channel.go
@@ -87,7 +87,9 @@ func (q *baseChannel) PopItem(ctx context.Context) ([]byte, error) {
 func (q *baseChannel) HasItem(ctx context.Context, data []byte) (bool, error) {
 	q.mu.Lock()
 	defer q.mu.Unlock()
-
+	if !q.isUnique {
+		return false, nil
+	}
 	return q.set.Contains(string(data)), nil
 }
 
@@ -107,7 +109,9 @@ func (q *baseChannel) Close() error {
 	defer q.mu.Unlock()
 
 	close(q.c)
-	q.set = container.Set[string]{}
+	if q.isUnique {
+		q.set = container.Set[string]{}
+	}
 
 	return nil
 }
@@ -119,5 +123,9 @@ func (q *baseChannel) RemoveAll(ctx context.Context) error {
 	for q.c != nil && len(q.c) > 0 {
 		<-q.c
 	}
+
+	if q.isUnique {
+		q.set = container.Set[string]{}
+	}
 	return nil
 }
diff --git a/modules/queue/base_levelqueue_unique.go b/modules/queue/base_levelqueue_unique.go
index 7546221631..1acd504e32 100644
--- a/modules/queue/base_levelqueue_unique.go
+++ b/modules/queue/base_levelqueue_unique.go
@@ -77,6 +77,14 @@ func (q *baseLevelQueueUnique) RemoveAll(ctx context.Context) error {
 	}
 	lq := (*levelUniqueQueue)(unsafe.Pointer(q.internal))
 
+	for lq.q.Len() > 0 {
+		if _, err := lq.q.LPop(); err != nil {
+			return err
+		}
+	}
+
+	// the "set" must be cleared after the "list" because there is no transaction.
+	// it's better to have duplicate items than losing items.
 	members, err := lq.set.Members()
 	if err != nil {
 		return err // seriously corrupted
@@ -84,10 +92,5 @@ func (q *baseLevelQueueUnique) RemoveAll(ctx context.Context) error {
 	for _, v := range members {
 		_, _ = lq.set.Remove(v)
 	}
-	for lq.q.Len() > 0 {
-		if _, err = lq.q.LPop(); err != nil {
-			return err
-		}
-	}
 	return nil
 }
diff --git a/modules/queue/base_redis.go b/modules/queue/base_redis.go
index a294077cc6..a1e234943d 100644
--- a/modules/queue/base_redis.go
+++ b/modules/queue/base_redis.go
@@ -123,7 +123,10 @@ func (q *baseRedis) Close() error {
 func (q *baseRedis) RemoveAll(ctx context.Context) error {
 	q.mu.Lock()
 	defer q.mu.Unlock()
+
 	c1 := q.client.Del(ctx, q.cfg.QueueFullName)
+	// the "set" must be cleared after the "list" because there is no transaction.
+	// it's better to have duplicate items than losing items.
 	c2 := q.client.Del(ctx, q.cfg.SetFullName)
 	if c1.Err() != nil {
 		return c1.Err()
diff --git a/modules/queue/manager.go b/modules/queue/manager.go
index 03dbc72da4..95b3bad57b 100644
--- a/modules/queue/manager.go
+++ b/modules/queue/manager.go
@@ -33,6 +33,9 @@ type ManagedWorkerPoolQueue interface {
 	// FlushWithContext tries to make the handler process all items in the queue synchronously.
 	// It is for testing purpose only. It's not designed to be used in a cluster.
 	FlushWithContext(ctx context.Context, timeout time.Duration) error
+
+	// RemoveAllItems removes all items in the base queue (on-the-fly items are not affected)
+	RemoveAllItems(ctx context.Context) error
 }
 
 var manager *Manager
diff --git a/modules/queue/workerqueue.go b/modules/queue/workerqueue.go
index 493bea17aa..de4485fa51 100644
--- a/modules/queue/workerqueue.go
+++ b/modules/queue/workerqueue.go
@@ -130,6 +130,11 @@ func (q *WorkerPoolQueue[T]) FlushWithContext(ctx context.Context, timeout time.
 	}
 }
 
+// RemoveAllItems removes all items in the baes queue
+func (q *WorkerPoolQueue[T]) RemoveAllItems(ctx context.Context) error {
+	return q.baseQueue.RemoveAll(ctx)
+}
+
 func (q *WorkerPoolQueue[T]) marshal(data T) []byte {
 	bs, err := json.Marshal(data)
 	if err != nil {
diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index f825220839..e5963e34c6 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -3040,8 +3040,9 @@ monitor.next = Next Time
 monitor.previous = Previous Time
 monitor.execute_times = Executions
 monitor.process = Running Processes
-monitor.stacktrace = Stacktraces
-monitor.goroutines = %d Goroutines
+monitor.stacktrace = Stacktrace
+monitor.processes_count = %d Processes
+monitor.download_diagnosis_report = Download diagnosis report
 monitor.desc = Description
 monitor.start = Start Time
 monitor.execute_time = Execution Time
@@ -3050,6 +3051,7 @@ monitor.process.cancel = Cancel process
 monitor.process.cancel_desc =  Cancelling a process may cause data loss
 monitor.process.cancel_notices =  Cancel: <strong>%s</strong>?
 monitor.process.children = Children
+
 monitor.queues = Queues
 monitor.queue = Queue: %s
 monitor.queue.name = Name
@@ -3060,56 +3062,15 @@ monitor.queue.maxnumberworkers = Max Number of Workers
 monitor.queue.numberinqueue = Number in Queue
 monitor.queue.review = Review Config
 monitor.queue.review_add = Review/Add Workers
-monitor.queue.configuration = Initial Configuration
-monitor.queue.nopool.title = No Worker Pool
-monitor.queue.nopool.desc = This queue wraps other queues and does not itself have a worker pool.
-monitor.queue.wrapped.desc = A wrapped queue wraps a slow starting queue, buffering queued requests in a channel. It does not have a worker pool itself.
-monitor.queue.persistable-channel.desc = A persistable-channel wraps two queues, a channel queue that has its own worker pool and a level queue for persisted requests from previous shutdowns. It does not have a worker pool itself.
-monitor.queue.flush = Flush worker
-monitor.queue.pool.timeout = Timeout
-monitor.queue.pool.addworkers.title = Add Workers
-monitor.queue.pool.addworkers.submit = Add Workers
-monitor.queue.pool.addworkers.desc = Add Workers to this pool with or without a timeout. If you set a timeout these workers will be removed from the pool after the timeout has lapsed.
-monitor.queue.pool.addworkers.numberworkers.placeholder = Number of Workers
-monitor.queue.pool.addworkers.timeout.placeholder = Set to 0 for no timeout
-monitor.queue.pool.addworkers.mustnumbergreaterzero = Number of Workers to add must be greater than zero
-monitor.queue.pool.addworkers.musttimeoutduration = Timeout must be a golang duration eg. 5m or be 0
-monitor.queue.pool.flush.title = Flush Queue
-monitor.queue.pool.flush.desc = Flush will add a worker that will terminate once the queue is empty, or it times out.
-monitor.queue.pool.flush.submit = Add Flush Worker
-monitor.queue.pool.flush.added = Flush Worker added for %[1]s
-monitor.queue.pool.pause.title = Pause Queue
-monitor.queue.pool.pause.desc = Pausing a Queue will prevent it from processing data
-monitor.queue.pool.pause.submit = Pause Queue
-monitor.queue.pool.resume.title = Resume Queue
-monitor.queue.pool.resume.desc = Set this queue to resume work
-monitor.queue.pool.resume.submit = Resume Queue
-
 monitor.queue.settings.title = Pool Settings
-monitor.queue.settings.desc = Pools dynamically grow with a boost in response to their worker queue blocking. These changes will not affect current worker groups.
-monitor.queue.settings.timeout = Boost Timeout
-monitor.queue.settings.timeout.placeholder = Currently %[1]v
-monitor.queue.settings.timeout.error = Timeout must be a golang duration eg. 5m or be 0
-monitor.queue.settings.numberworkers = Boost Number of Workers
-monitor.queue.settings.numberworkers.placeholder = Currently %[1]d
-monitor.queue.settings.numberworkers.error = Number of Workers to add must be greater than or equal to zero
+monitor.queue.settings.desc = Pools dynamically grow in response to their worker queue blocking.
 monitor.queue.settings.maxnumberworkers = Max Number of workers
 monitor.queue.settings.maxnumberworkers.placeholder = Currently %[1]d
 monitor.queue.settings.maxnumberworkers.error = Max number of workers must be a number
 monitor.queue.settings.submit = Update Settings
 monitor.queue.settings.changed = Settings Updated
-monitor.queue.settings.blocktimeout = Current Block Timeout
-monitor.queue.settings.blocktimeout.value = %[1]v
-
-monitor.queue.pool.none = This queue does not have a Pool
-monitor.queue.pool.added = Worker Group Added
-monitor.queue.pool.max_changed = Maximum number of workers changed
-monitor.queue.pool.workers.title = Active Worker Groups
-monitor.queue.pool.workers.none = No worker groups.
-monitor.queue.pool.cancel = Shutdown Worker Group
-monitor.queue.pool.cancelling = Worker Group shutting down
-monitor.queue.pool.cancel_notices = Shutdown this group of %s workers?
-monitor.queue.pool.cancel_desc = Leaving a queue without any worker groups may cause requests to block indefinitely.
+monitor.queue.settings.remove_all_items = Remove all
+monitor.queue.settings.remove_all_items_done = All items in the queue have been removed.
 
 notices.system_notice_list = System Notices
 notices.view_detail_header = View Notice Details
diff --git a/routers/web/admin/admin.go b/routers/web/admin/admin.go
index cbe1482a24..1ada4deefc 100644
--- a/routers/web/admin/admin.go
+++ b/routers/web/admin/admin.go
@@ -13,8 +13,6 @@ import (
 	activities_model "code.gitea.io/gitea/models/activities"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/context"
-	"code.gitea.io/gitea/modules/process"
-	"code.gitea.io/gitea/modules/queue"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/updatechecker"
 	"code.gitea.io/gitea/modules/web"
@@ -24,7 +22,8 @@ import (
 
 const (
 	tplDashboard   base.TplName = "admin/dashboard"
-	tplMonitor     base.TplName = "admin/monitor"
+	tplCron        base.TplName = "admin/cron"
+	tplQueue       base.TplName = "admin/queue"
 	tplStacktrace  base.TplName = "admin/stacktrace"
 	tplQueueManage base.TplName = "admin/queue_manage"
 )
@@ -142,47 +141,15 @@ func DashboardPost(ctx *context.Context) {
 		}
 	}
 	if form.From == "monitor" {
-		ctx.Redirect(setting.AppSubURL + "/admin/monitor")
+		ctx.Redirect(setting.AppSubURL + "/admin/monitor/cron")
 	} else {
 		ctx.Redirect(setting.AppSubURL + "/admin")
 	}
 }
 
-// Monitor show admin monitor page
-func Monitor(ctx *context.Context) {
-	ctx.Data["Title"] = ctx.Tr("admin.monitor")
-	ctx.Data["PageIsAdminMonitor"] = true
-	ctx.Data["Processes"], ctx.Data["ProcessCount"] = process.GetManager().Processes(false, true)
+func CronTasks(ctx *context.Context) {
+	ctx.Data["Title"] = ctx.Tr("admin.monitor.cron")
+	ctx.Data["PageIsAdminMonitorCron"] = true
 	ctx.Data["Entries"] = cron.ListTasks()
-	ctx.Data["Queues"] = queue.GetManager().ManagedQueues()
-
-	ctx.HTML(http.StatusOK, tplMonitor)
-}
-
-// GoroutineStacktrace show admin monitor goroutines page
-func GoroutineStacktrace(ctx *context.Context) {
-	ctx.Data["Title"] = ctx.Tr("admin.monitor")
-	ctx.Data["PageIsAdminMonitor"] = true
-
-	processStacks, processCount, goroutineCount, err := process.GetManager().ProcessStacktraces(false, false)
-	if err != nil {
-		ctx.ServerError("GoroutineStacktrace", err)
-		return
-	}
-
-	ctx.Data["ProcessStacks"] = processStacks
-
-	ctx.Data["GoroutineCount"] = goroutineCount
-	ctx.Data["ProcessCount"] = processCount
-
-	ctx.HTML(http.StatusOK, tplStacktrace)
-}
-
-// MonitorCancel cancels a process
-func MonitorCancel(ctx *context.Context) {
-	pid := ctx.Params("pid")
-	process.GetManager().Cancel(process.IDType(pid))
-	ctx.JSON(http.StatusOK, map[string]interface{}{
-		"redirect": setting.AppSubURL + "/admin/monitor",
-	})
+	ctx.HTML(http.StatusOK, tplCron)
 }
diff --git a/routers/web/admin/diagnosis.go b/routers/web/admin/diagnosis.go
new file mode 100644
index 0000000000..5637894e6d
--- /dev/null
+++ b/routers/web/admin/diagnosis.go
@@ -0,0 +1,61 @@
+// Copyright 2023 The Gitea Authors.
+// SPDX-License-Identifier: MIT
+
+package admin
+
+import (
+	"archive/zip"
+	"fmt"
+	"runtime/pprof"
+	"time"
+
+	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/httplib"
+)
+
+func MonitorDiagnosis(ctx *context.Context) {
+	seconds := ctx.FormInt64("seconds")
+	if seconds <= 5 {
+		seconds = 5
+	}
+	if seconds > 300 {
+		seconds = 300
+	}
+
+	httplib.ServeSetHeaders(ctx.Resp, &httplib.ServeHeaderOptions{
+		ContentType: "application/zip",
+		Disposition: "attachment",
+		Filename:    fmt.Sprintf("gitea-diagnosis-%s.zip", time.Now().Format("20060102-150405")),
+	})
+
+	zipWriter := zip.NewWriter(ctx.Resp)
+	defer zipWriter.Close()
+
+	f, err := zipWriter.CreateHeader(&zip.FileHeader{Name: "goroutine-before.txt", Method: zip.Deflate, Modified: time.Now()})
+	if err != nil {
+		ctx.ServerError("Failed to create zip file", err)
+		return
+	}
+	_ = pprof.Lookup("goroutine").WriteTo(f, 1)
+
+	f, err = zipWriter.CreateHeader(&zip.FileHeader{Name: "cpu-profile.dat", Method: zip.Deflate, Modified: time.Now()})
+	if err != nil {
+		ctx.ServerError("Failed to create zip file", err)
+		return
+	}
+
+	err = pprof.StartCPUProfile(f)
+	if err == nil {
+		time.Sleep(time.Duration(seconds) * time.Second)
+		pprof.StopCPUProfile()
+	} else {
+		_, _ = f.Write([]byte(err.Error()))
+	}
+
+	f, err = zipWriter.CreateHeader(&zip.FileHeader{Name: "goroutine-after.txt", Method: zip.Deflate, Modified: time.Now()})
+	if err != nil {
+		ctx.ServerError("Failed to create zip file", err)
+		return
+	}
+	_ = pprof.Lookup("goroutine").WriteTo(f, 1)
+}
diff --git a/routers/web/admin/queue.go b/routers/web/admin/queue.go
index 1d57bc54c9..4e01846ba8 100644
--- a/routers/web/admin/queue.go
+++ b/routers/web/admin/queue.go
@@ -12,8 +12,18 @@ import (
 	"code.gitea.io/gitea/modules/setting"
 )
 
-// Queue shows details for a specific queue
-func Queue(ctx *context.Context) {
+func Queues(ctx *context.Context) {
+	if !setting.IsProd {
+		initTestQueueOnce()
+	}
+	ctx.Data["Title"] = ctx.Tr("admin.monitor.queue")
+	ctx.Data["PageIsAdminMonitorQueue"] = true
+	ctx.Data["Queues"] = queue.GetManager().ManagedQueues()
+	ctx.HTML(http.StatusOK, tplQueue)
+}
+
+// QueueManage shows details for a specific queue
+func QueueManage(ctx *context.Context) {
 	qid := ctx.ParamsInt64("qid")
 	mq := queue.GetManager().GetManagedQueue(qid)
 	if mq == nil {
@@ -57,3 +67,23 @@ func QueueSet(ctx *context.Context) {
 	ctx.Flash.Success(ctx.Tr("admin.monitor.queue.settings.changed"))
 	ctx.Redirect(setting.AppSubURL + "/admin/monitor/queue/" + strconv.FormatInt(qid, 10))
 }
+
+func QueueRemoveAllItems(ctx *context.Context) {
+	// Gitea's queue doesn't have transaction support
+	// So in rare cases, the queue could be corrupted/out-of-sync
+	// Site admin could remove all items from the queue to make it work again
+	qid := ctx.ParamsInt64("qid")
+	mq := queue.GetManager().GetManagedQueue(qid)
+	if mq == nil {
+		ctx.Status(http.StatusNotFound)
+		return
+	}
+
+	if err := mq.RemoveAllItems(ctx); err != nil {
+		ctx.ServerError("RemoveAllItems", err)
+		return
+	}
+
+	ctx.Flash.Success(ctx.Tr("admin.monitor.queue.settings.remove_all_items_done"))
+	ctx.Redirect(setting.AppSubURL + "/admin/monitor/queue/" + strconv.FormatInt(qid, 10))
+}
diff --git a/routers/web/admin/queue_tester.go b/routers/web/admin/queue_tester.go
new file mode 100644
index 0000000000..96373c4d5f
--- /dev/null
+++ b/routers/web/admin/queue_tester.go
@@ -0,0 +1,72 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package admin
+
+import (
+	gocontext "context"
+	"sync"
+	"time"
+
+	"code.gitea.io/gitea/modules/graceful"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/queue"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+var testQueueOnce sync.Once
+
+// initTestQueueOnce initializes the test queue for dev mode
+// the test queue will also be shown in the queue list
+// developers could see the queue length / worker number / items number on the admin page and try to remove the items
+func initTestQueueOnce() {
+	testQueueOnce.Do(func() {
+		qs := setting.QueueSettings{
+			Name:        "test-queue",
+			Type:        "channel",
+			Length:      20,
+			BatchLength: 2,
+			MaxWorkers:  3,
+		}
+		testQueue, err := queue.NewWorkerPoolQueueBySetting("test-queue", qs, func(t ...int64) (unhandled []int64) {
+			for range t {
+				select {
+				case <-graceful.GetManager().ShutdownContext().Done():
+				case <-time.After(5 * time.Second):
+				}
+			}
+			return nil
+		}, true)
+		if err != nil {
+			log.Error("unable to create test queue: %v", err)
+			return
+		}
+
+		queue.GetManager().AddManagedQueue(testQueue)
+		testQueue.SetWorkerMaxNumber(5)
+		go graceful.GetManager().RunWithShutdownFns(testQueue.Run)
+		go graceful.GetManager().RunWithShutdownContext(func(ctx gocontext.Context) {
+			cnt := int64(0)
+			adding := true
+			for {
+				select {
+				case <-ctx.Done():
+				case <-time.After(500 * time.Millisecond):
+					if adding {
+						if testQueue.GetQueueItemNumber() == qs.Length {
+							adding = false
+						}
+					} else {
+						if testQueue.GetQueueItemNumber() == 0 {
+							adding = true
+						}
+					}
+					if adding {
+						_ = testQueue.Push(cnt)
+						cnt++
+					}
+				}
+			}
+		})
+	})
+}
diff --git a/routers/web/admin/stacktrace.go b/routers/web/admin/stacktrace.go
new file mode 100644
index 0000000000..4b225c2c8a
--- /dev/null
+++ b/routers/web/admin/stacktrace.go
@@ -0,0 +1,48 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package admin
+
+import (
+	"net/http"
+	"runtime"
+
+	"code.gitea.io/gitea/modules/context"
+	"code.gitea.io/gitea/modules/process"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+// Stacktrace show admin monitor goroutines page
+func Stacktrace(ctx *context.Context) {
+	ctx.Data["Title"] = ctx.Tr("admin.monitor")
+	ctx.Data["PageIsAdminMonitorStacktrace"] = true
+
+	ctx.Data["GoroutineCount"] = runtime.NumGoroutine()
+
+	show := ctx.FormString("show")
+	ctx.Data["ShowGoroutineList"] = show
+	// by default, do not do anything which might cause server errors, to avoid unnecessary 500 pages.
+	// this page is the entrance of the chance to collect diagnosis report.
+	if show != "" {
+		showNoSystem := show == "process"
+		processStacks, processCount, _, err := process.GetManager().ProcessStacktraces(false, showNoSystem)
+		if err != nil {
+			ctx.ServerError("GoroutineStacktrace", err)
+			return
+		}
+
+		ctx.Data["ProcessStacks"] = processStacks
+		ctx.Data["ProcessCount"] = processCount
+	}
+
+	ctx.HTML(http.StatusOK, tplStacktrace)
+}
+
+// StacktraceCancel cancels a process
+func StacktraceCancel(ctx *context.Context) {
+	pid := ctx.Params("pid")
+	process.GetManager().Cancel(process.IDType(pid))
+	ctx.JSON(http.StatusOK, map[string]interface{}{
+		"redirect": setting.AppSubURL + "/admin/monitor/stacktrace",
+	})
+}
diff --git a/routers/web/web.go b/routers/web/web.go
index b0db8892ea..d0deb845fc 100644
--- a/routers/web/web.go
+++ b/routers/web/web.go
@@ -546,13 +546,16 @@ func registerRoutes(m *web.Route) {
 		})
 
 		m.Group("/monitor", func() {
-			m.Get("", admin.Monitor)
-			m.Get("/stacktrace", admin.GoroutineStacktrace)
-			m.Post("/cancel/{pid}", admin.MonitorCancel)
+			m.Get("/cron", admin.CronTasks)
+			m.Get("/stacktrace", admin.Stacktrace)
+			m.Post("/stacktrace/cancel/{pid}", admin.StacktraceCancel)
+			m.Get("/queue", admin.Queues)
 			m.Group("/queue/{qid}", func() {
-				m.Get("", admin.Queue)
+				m.Get("", admin.QueueManage)
 				m.Post("/set", admin.QueueSet)
+				m.Post("/remove-all-items", admin.QueueRemoveAllItems)
 			})
+			m.Get("/diagnosis", admin.MonitorDiagnosis)
 		})
 
 		m.Group("/users", func() {
diff --git a/templates/admin/cron.tmpl b/templates/admin/cron.tmpl
index a7f4405620..fe3c88aec1 100644
--- a/templates/admin/cron.tmpl
+++ b/templates/admin/cron.tmpl
@@ -1,35 +1,39 @@
-<h4 class="ui top attached header">
-	{{.locale.Tr "admin.monitor.cron"}}
-</h4>
-<div class="ui attached table segment">
-	<form method="post" action="{{AppSubUrl}}/admin">
-		<table class="ui very basic striped table unstackable">
-			<thead>
-				<tr>
-					<th></th>
-					<th>{{.locale.Tr "admin.monitor.name"}}</th>
-					<th>{{.locale.Tr "admin.monitor.schedule"}}</th>
-					<th>{{.locale.Tr "admin.monitor.next"}}</th>
-					<th>{{.locale.Tr "admin.monitor.previous"}}</th>
-					<th>{{.locale.Tr "admin.monitor.execute_times"}}</th>
-					<th>{{.locale.Tr "admin.monitor.last_execution_result"}}</th>
-				</tr>
-			</thead>
-			<tbody>
-				{{range .Entries}}
+{{template "admin/layout_head" (dict "ctxData" . "pageClass" "admin monitor")}}
+<div class="admin-setting-content">
+	<h4 class="ui top attached header">
+		{{.locale.Tr "admin.monitor.cron"}}
+	</h4>
+	<div class="ui attached table segment">
+		<form method="post" action="{{AppSubUrl}}/admin">
+			<table class="ui very basic striped table unstackable">
+				<thead>
 					<tr>
-						<td><button type="submit" class="ui green button" name="op" value="{{.Name}}" title="{{$.locale.Tr "admin.dashboard.operation_run"}}">{{svg "octicon-triangle-right"}}</button></td>
-						<td>{{$.locale.Tr (printf "admin.dashboard.%s" .Name)}}</td>
-						<td>{{.Spec}}</td>
-						<td>{{DateTime "full" .Next}}</td>
-						<td>{{if gt .Prev.Year 1}}{{DateTime "full" .Prev}}{{else}}-{{end}}</td>
-						<td>{{.ExecTimes}}</td>
-						<td {{if ne .Status ""}}data-tooltip-content="{{.FormatLastMessage $.locale}}"{{end}} >{{if eq .Status ""}}—{{else if eq .Status "finished"}}{{svg "octicon-check" 16}}{{else}}{{svg "octicon-x" 16}}{{end}}</td>
+						<th></th>
+						<th>{{.locale.Tr "admin.monitor.name"}}</th>
+						<th>{{.locale.Tr "admin.monitor.schedule"}}</th>
+						<th>{{.locale.Tr "admin.monitor.next"}}</th>
+						<th>{{.locale.Tr "admin.monitor.previous"}}</th>
+						<th>{{.locale.Tr "admin.monitor.execute_times"}}</th>
+						<th>{{.locale.Tr "admin.monitor.last_execution_result"}}</th>
 					</tr>
-				{{end}}
-			</tbody>
-		</table>
-		<input type="hidden" name="from" value="monitor">
-		{{.CsrfTokenHtml}}
-	</form>
+				</thead>
+				<tbody>
+					{{range .Entries}}
+						<tr>
+							<td><button type="submit" class="ui green button" name="op" value="{{.Name}}" title="{{$.locale.Tr "admin.dashboard.operation_run"}}">{{svg "octicon-triangle-right"}}</button></td>
+							<td>{{$.locale.Tr (printf "admin.dashboard.%s" .Name)}}</td>
+							<td>{{.Spec}}</td>
+							<td>{{DateTime "full" .Next}}</td>
+							<td>{{if gt .Prev.Year 1}}{{DateTime "full" .Prev}}{{else}}-{{end}}</td>
+							<td>{{.ExecTimes}}</td>
+							<td {{if ne .Status ""}}data-tooltip-content="{{.FormatLastMessage $.locale}}"{{end}} >{{if eq .Status ""}}—{{else if eq .Status "finished"}}{{svg "octicon-check" 16}}{{else}}{{svg "octicon-x" 16}}{{end}}</td>
+						</tr>
+					{{end}}
+				</tbody>
+			</table>
+			<input type="hidden" name="from" value="monitor">
+			{{.CsrfTokenHtml}}
+		</form>
+	</div>
 </div>
+{{template "admin/layout_footer" .}}
diff --git a/templates/admin/monitor.tmpl b/templates/admin/monitor.tmpl
deleted file mode 100644
index 6a13b7b552..0000000000
--- a/templates/admin/monitor.tmpl
+++ /dev/null
@@ -1,19 +0,0 @@
-{{template "admin/layout_head" (dict "ctxData" . "pageClass" "admin monitor")}}
-	<div class="admin-setting-content">
-		{{template "admin/cron" .}}
-		{{template "admin/queue" .}}
-		{{template "admin/process" .}}
-	</div>
-
-<div class="ui g-modal-confirm delete modal">
-	<div class="header">
-		{{.locale.Tr "admin.monitor.process.cancel"}}
-	</div>
-	<div class="content">
-		<p>{{$.locale.Tr "admin.monitor.process.cancel_notices" `<span class="name"></span>` | Safe}}</p>
-		<p>{{$.locale.Tr "admin.monitor.process.cancel_desc"}}</p>
-	</div>
-	{{template "base/modal_actions_confirm" .}}
-</div>
-
-{{template "admin/layout_footer" .}}
diff --git a/templates/admin/navbar.tmpl b/templates/admin/navbar.tmpl
index 51a93bacd7..eff5f1d83a 100644
--- a/templates/admin/navbar.tmpl
+++ b/templates/admin/navbar.tmpl
@@ -50,8 +50,19 @@
 		<a class="{{if .PageIsAdminNotices}}active {{end}}item" href="{{AppSubUrl}}/admin/notices">
 			{{.locale.Tr "admin.notices"}}
 		</a>
-		<a class="{{if .PageIsAdminMonitor}}active {{end}}item" href="{{AppSubUrl}}/admin/monitor">
+		<div class="item">
 			{{.locale.Tr "admin.monitor"}}
-		</a>
+			<div class="menu">
+				<a class="{{if .PageIsAdminMonitorCron}}active {{end}}item" href="{{AppSubUrl}}/admin/monitor/cron">
+					{{.locale.Tr "admin.monitor.cron"}}
+				</a>
+				<a class="{{if .PageIsAdminMonitorQueue}}active {{end}}item" href="{{AppSubUrl}}/admin/monitor/queue">
+					{{.locale.Tr "admin.monitor.queues"}}
+				</a>
+				<a class="{{if .PageIsAdminMonitorStacktrace}}active {{end}}item" href="{{AppSubUrl}}/admin/monitor/stacktrace">
+					{{.locale.Tr "admin.monitor.stacktrace"}}
+				</a>
+			</div>
+		</div>
 	</div>
 </div>
diff --git a/templates/admin/process-row.tmpl b/templates/admin/process-row.tmpl
deleted file mode 100644
index 8fd2d1af70..0000000000
--- a/templates/admin/process-row.tmpl
+++ /dev/null
@@ -1,23 +0,0 @@
-<div class="item">
-	<div class="gt-df gt-ac">
-		<div class="icon gt-ml-3 gt-mr-3">{{if eq .Process.Type "request"}}{{svg "octicon-globe" 16}}{{else if eq .Process.Type "system"}}{{svg "octicon-cpu" 16}}{{else}}{{svg "octicon-terminal" 16}}{{end}}</div>
-		<div class="content gt-f1">
-			<div class="header">{{.Process.Description}}</div>
-			<div class="description">{{TimeSince .Process.Start .root.locale}}</div>
-		</div>
-		<div>
-			{{if ne .Process.Type "system"}}
-				<a class="delete-button icon" href="" data-url="{{.root.Link}}/cancel/{{.Process.PID}}" data-id="{{.Process.PID}}" data-name="{{.Process.Description}}">{{svg "octicon-trash" 16 "text-red"}}</a>
-			{{end}}
-		</div>
-	</div>
-
-	{{$children := .Process.Children}}
-	{{if $children}}
-		<div class="divided list">
-			{{range $children}}
-				{{template "admin/process-row" dict "Process" . "root" $.root}}
-			{{end}}
-		</div>
-	{{end}}
-</div>
diff --git a/templates/admin/process.tmpl b/templates/admin/process.tmpl
deleted file mode 100644
index bd5bcfb3a2..0000000000
--- a/templates/admin/process.tmpl
+++ /dev/null
@@ -1,13 +0,0 @@
-<h4 class="ui top attached header">
-	{{.locale.Tr "admin.monitor.process"}}
-	<div class="ui right">
-		<a class="ui primary tiny button" href="{{AppSubUrl}}/admin/monitor/stacktrace">{{.locale.Tr "admin.monitor.stacktrace"}}</a>
-	</div>
-</h4>
-<div class="ui attached segment">
-	<div class="ui relaxed divided list">
-			{{range .Processes}}
-				{{template "admin/process-row" dict "Process" . "root" $}}
-			{{end}}
-	</div>
-</div>
diff --git a/templates/admin/queue.tmpl b/templates/admin/queue.tmpl
index 5bd507e69f..f58f25e4ae 100644
--- a/templates/admin/queue.tmpl
+++ b/templates/admin/queue.tmpl
@@ -1,29 +1,34 @@
-<h4 class="ui top attached header">
-	{{.locale.Tr "admin.monitor.queues"}}
-</h4>
-<div class="ui attached table segment">
-	<table class="ui very basic striped table unstackable">
-		<thead>
-		<tr>
-			<th>{{.locale.Tr "admin.monitor.queue.name"}}</th>
-			<th>{{.locale.Tr "admin.monitor.queue.type"}}</th>
-			<th>{{.locale.Tr "admin.monitor.queue.exemplar"}}</th>
-			<th>{{.locale.Tr "admin.monitor.queue.numberworkers"}}</th>
-			<th>{{.locale.Tr "admin.monitor.queue.numberinqueue"}}</th>
-			<th></th>
-		</tr>
-		</thead>
-		<tbody>
-		{{range $qid, $q := .Queues}}
-		<tr>
-			<td>{{$q.GetName}}</td>
-			<td>{{$q.GetType}}</td>
-			<td>{{$q.GetItemTypeName}}</td>
-			<td>{{$sum := $q.GetWorkerNumber}}{{if lt $sum 0}}-{{else}}{{$sum}}{{end}}</td>
-			<td>{{$sum = $q.GetQueueItemNumber}}{{if lt $sum 0}}-{{else}}{{$sum}}{{end}}</td>
-			<td><a href="{{$.Link}}/queue/{{$qid}}" class="button">{{if lt $sum 0}}{{$.locale.Tr "admin.monitor.queue.review"}}{{else}}{{$.locale.Tr "admin.monitor.queue.review_add"}}{{end}}</a>
-		</tr>
-		{{end}}
-		</tbody>
-	</table>
+{{template "admin/layout_head" (dict "ctxData" . "pageClass" "admin monitor")}}
+<div class="admin-setting-content">
+	<h4 class="ui top attached header">
+		{{.locale.Tr "admin.monitor.queues"}}
+	</h4>
+	<div class="ui attached table segment">
+		<table class="ui very basic striped table unstackable">
+			<thead>
+			<tr>
+				<th>{{.locale.Tr "admin.monitor.queue.name"}}</th>
+				<th>{{.locale.Tr "admin.monitor.queue.type"}}</th>
+				<th>{{.locale.Tr "admin.monitor.queue.exemplar"}}</th>
+				<th>{{.locale.Tr "admin.monitor.queue.numberworkers"}}</th>
+				<th>{{.locale.Tr "admin.monitor.queue.numberinqueue"}}</th>
+				<th></th>
+			</tr>
+			</thead>
+			<tbody>
+			{{range $qid, $q := .Queues}}
+			<tr>
+				<td>{{$q.GetName}}</td>
+				<td>{{$q.GetType}}</td>
+				<td>{{$q.GetItemTypeName}}</td>
+				<td>{{$sum := $q.GetWorkerNumber}}{{if lt $sum 0}}-{{else}}{{$sum}}{{end}}</td>
+				<td>{{$sum = $q.GetQueueItemNumber}}{{if lt $sum 0}}-{{else}}{{$sum}}{{end}}</td>
+				<td><a href="{{$.Link}}/{{$qid}}" class="button">{{if lt $sum 0}}{{$.locale.Tr "admin.monitor.queue.review"}}{{else}}{{$.locale.Tr "admin.monitor.queue.review_add"}}{{end}}</a>
+			</tr>
+			{{end}}
+			</tbody>
+		</table>
+	</div>
 </div>
+{{template "admin/layout_footer" .}}
+
diff --git a/templates/admin/queue_manage.tmpl b/templates/admin/queue_manage.tmpl
index 60d6b426b9..d456c2fbab 100644
--- a/templates/admin/queue_manage.tmpl
+++ b/templates/admin/queue_manage.tmpl
@@ -22,7 +22,18 @@
 						<td>{{.Queue.GetItemTypeName}}</td>
 						<td>{{$sum := .Queue.GetWorkerNumber}}{{if lt $sum 0}}-{{else}}{{$sum}}{{end}}</td>
 						<td>{{if lt $sum 0}}-{{else}}{{.Queue.GetWorkerMaxNumber}}{{end}}</td>
-						<td>{{$sum = .Queue.GetQueueItemNumber}}{{if lt $sum 0}}-{{else}}{{$sum}}{{end}}</td>
+						<td>
+							{{$sum = .Queue.GetQueueItemNumber}}
+							{{if lt $sum 0}}
+								-
+							{{else}}
+								{{$sum}}
+								<form action="{{$.Link}}/remove-all-items" method="post" class="gt-dib gt-ml-4">
+									{{$.CsrfTokenHtml}}
+									<button class="ui tiny basic red button">{{.locale.Tr "admin.monitor.queue.settings.remove_all_items"}}</button>
+								</form>
+							{{end}}
+						</td>
 					</tr>
 				</tbody>
 			</table>
diff --git a/templates/admin/stacktrace.tmpl b/templates/admin/stacktrace.tmpl
index 2ffb9982f2..46ad421587 100644
--- a/templates/admin/stacktrace.tmpl
+++ b/templates/admin/stacktrace.tmpl
@@ -1,19 +1,38 @@
 {{template "admin/layout_head" (dict "ctxData" . "pageClass" "admin monitor")}}
-	<div class="admin-setting-content">
-		<h4 class="ui top attached header">
-			{{.locale.Tr "admin.monitor.stacktrace"}}: {{.locale.Tr "admin.monitor.goroutines" .GoroutineCount}}
-			<div class="ui right">
-				<a class="ui primary tiny button" href="{{AppSubUrl}}/admin/monitor">{{.locale.Tr "admin.monitor"}}</a>
+<div class="admin-setting-content">
+
+	<div class="gt-df gt-ac">
+		<div class="gt-f1">
+			<div class="ui compact small menu">
+				<a class="{{if eq .ShowGoroutineList "process"}}active {{end}}item" href="{{.Link}}?show=process">{{.locale.Tr "admin.monitor.process"}}</a>
+				<a class="{{if eq .ShowGoroutineList "stacktrace"}}active {{end}}item" href="{{.Link}}?show=stacktrace">{{.locale.Tr "admin.monitor.stacktrace"}}</a>
 			</div>
-		</h4>
-		<div class="ui attached segment">
-			<div class="ui relaxed divided list">
-				{{range .ProcessStacks}}
-					{{template "admin/stacktrace-row" dict "Process" . "root" $}}
-				{{end}}
+		</div>
+		<form target="_blank" action="{{AppSubUrl}}/admin/monitor/diagnosis" class="ui form">
+			<div class="ui inline field">
+				<button class="ui primary small button">{{.locale.Tr "admin.monitor.download_diagnosis_report"}}</button>
+				<input name="seconds" size="3" maxlength="3" value="10"> {{.locale.Tr "tool.raw_seconds"}}
 			</div>
+		</form>
+	</div>
+
+	<div class="ui divider"></div>
+
+	<h4 class="ui top attached header">
+		{{printf "%d Goroutines" .GoroutineCount}}{{/* Goroutine is non-translatable*/}}
+		{{- if .ProcessCount -}}, {{.locale.Tr "admin.monitor.processes_count" .ProcessCount}}{{- end -}}
+	</h4>
+
+	{{if .ProcessStacks}}
+	<div class="ui attached segment">
+		<div class="ui relaxed divided list">
+			{{range .ProcessStacks}}
+				{{template "admin/stacktrace-row" dict "Process" . "root" $}}
+			{{end}}
 		</div>
 	</div>
+	{{end}}
+</div>
 
 <div class="ui g-modal-confirm delete modal">
 	<div class="header">