Compare commits

..

3 commits

Author SHA1 Message Date
b5ed0b6eff
[#14] CODEOWNERS: Use core commiters and developers groups
Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
2025-03-31 11:04:22 +03:00
6c6e5bf4de
[#14] mclock: Allow to prohibit tag requests
It is now possible to restrict requests for a specific tag.
A separate field in `TagInfo` is used to avoid comparing float64 values with zero.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
2025-03-31 11:04:08 +03:00
57d895c321
[#13] mclock: Schedule requests as soon as possible
Let's assume that for some tag `limit = 1000 RPS` defined and each
request takes 10 ms to complete. At some point in time 1000 requests
were accepted. Then first request will be scheduled at `now()`, second -
at `now() + 1 ms`, third - at `now() + 2 ms` etc. Total processing
duration of 1000 requests will be 1 second + 10 ms.

After this fix scheduler looks forward to schedule requests within limit.
So for situation above total processing duration of 1000 requests will be
10 ms in ideal world.

The same for reservation scheduling.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>
2025-03-24 16:36:47 +03:00
3 changed files with 79 additions and 7 deletions

View file

@ -1,3 +1,3 @@
.* @fyrchik .* @TrueCloudLab/storage-core-committers @TrueCloudLab/storage-core-developers
.forgejo/.* @potyarkin .forgejo/.* @potyarkin
Makefile @potyarkin Makefile @potyarkin

View file

@ -22,6 +22,7 @@ var (
ErrMClockSchedulerUnknownTag = errors.New("unknown tag") ErrMClockSchedulerUnknownTag = errors.New("unknown tag")
ErrInvalidTagInfo = errors.New("invalid tag info: shares, limit and reservation must be greater than zero") ErrInvalidTagInfo = errors.New("invalid tag info: shares, limit and reservation must be greater than zero")
ErrInvalidRunLimit = errors.New("invalid run limit: must be greater than zero") ErrInvalidRunLimit = errors.New("invalid run limit: must be greater than zero")
ErrTagRequestsProhibited = errors.New("tag requests are prohibited")
) )
type request struct { type request struct {
@ -49,6 +50,7 @@ type TagInfo struct {
ReservedIOPS *float64 ReservedIOPS *float64
LimitIOPS *float64 LimitIOPS *float64
Share float64 Share float64
Prohibited bool
} }
// MClock is mClock scheduling algorithm implementation. // MClock is mClock scheduling algorithm implementation.
@ -196,6 +198,9 @@ func (q *MClock) pushRequest(tag string) (*request, ReleaseFunc, error) {
if !ok { if !ok {
return nil, nil, ErrMClockSchedulerUnknownTag return nil, nil, ErrMClockSchedulerUnknownTag
} }
if tagInfo.Prohibited {
return nil, nil, ErrTagRequestsProhibited
}
prev, ok := q.previous[tag] prev, ok := q.previous[tag]
assert.Cond(ok, "undefined previous:", tag) assert.Cond(ok, "undefined previous:", tag)
@ -306,7 +311,7 @@ func (q *MClock) setNextScheduleTimer(now float64) {
} }
func (q *MClock) scheduleByLimitAndWeight(now float64) { func (q *MClock) scheduleByLimitAndWeight(now float64) {
for q.limitQueue.Len() > 0 && q.limitQueue.items[0].ts() <= now { for q.limitQueue.Len() > 0 && q.limitQueue.items[0].ts() < now+1.0 {
ready := heap.Pop(q.limitQueue).(*limitMQueueItem) ready := heap.Pop(q.limitQueue).(*limitMQueueItem)
heap.Push(q.readyQueue, &readyMQueueItem{r: ready.r}) heap.Push(q.readyQueue, &readyMQueueItem{r: ready.r})
} }
@ -349,7 +354,7 @@ func (q *MClock) scheduleByLimitAndWeight(now float64) {
} }
func (q *MClock) scheduleByReservation(now float64) { func (q *MClock) scheduleByReservation(now float64) {
for q.inProgress < q.runLimit && q.reservationQueue.Len() > 0 && q.reservationQueue.items[0].ts() <= now { for q.inProgress < q.runLimit && q.reservationQueue.Len() > 0 && q.reservationQueue.items[0].ts() < now+1.0 {
next := heap.Pop(q.reservationQueue).(*reservationMQueueItem) next := heap.Pop(q.reservationQueue).(*reservationMQueueItem)
q.removeFromQueues(next.r) q.removeFromQueues(next.r)

View file

@ -210,7 +210,7 @@ func TestMClockReservationScheduling(t *testing.T) {
reqCount = (reqCount / 2) * 2 reqCount = (reqCount / 2) * 2
limit := 0.01 // 1 request in 100 seconds limit := 0.01 // 1 request in 100 seconds
resevation := 100.0 // 100 RPS resevation := 100.0 // 100 RPS
cl := &noopClock{} cl := &noopClock{v: float64(1.0)}
q, err := NewMClock(uint64(reqCount), math.MaxUint64, map[string]TagInfo{ q, err := NewMClock(uint64(reqCount), math.MaxUint64, map[string]TagInfo{
"class1": {Share: 2, LimitIOPS: &limit}, "class1": {Share: 2, LimitIOPS: &limit},
"class2": {Share: 1, LimitIOPS: &limit, ReservedIOPS: &resevation}, "class2": {Share: 1, LimitIOPS: &limit, ReservedIOPS: &resevation},
@ -237,15 +237,18 @@ func TestMClockReservationScheduling(t *testing.T) {
q.scheduleRequest() q.scheduleRequest()
count := 0
for _, req := range requests { for _, req := range requests {
select { select {
case <-req.scheduled: case <-req.scheduled:
require.Fail(t, "no request must be scheduled because of time is 0.0 but limit values are greater than 0.0") require.Equal(t, req.tag, "class2")
count++
default: default:
} }
} }
require.Equal(t, 100, count, "class2 has 100 requests reserved, so only 100 requests must be scheduled")
cl.v = 1.00001 // 1s elapsed cl.v = 1.9999 // 1s elapsed - 0.999 to take into account float64 accuracy
q.scheduleRequest() q.scheduleRequest()
var result []string var result []string
@ -258,7 +261,7 @@ func TestMClockReservationScheduling(t *testing.T) {
} }
} }
require.Equal(t, 100, len(result)) require.Equal(t, 200, len(result))
for _, res := range result { for _, res := range result {
require.Equal(t, "class2", res) require.Equal(t, "class2", res)
} }
@ -515,3 +518,67 @@ func TestMClockLowLimit(t *testing.T) {
}) })
require.NoError(t, eg.Wait()) require.NoError(t, eg.Wait())
} }
func TestMClockLimitTotalTime(t *testing.T) {
t.Parallel()
limit := 10.0 // 10 RPS -> 1 request per 100 ms
q, err := NewMClock(100, 100, map[string]TagInfo{
"class1": {Share: 50, LimitIOPS: &limit},
}, 5*time.Second)
require.NoError(t, err)
defer q.Close()
// 10 requests, each request runs for 500 ms,
// but they should be scheduled as soon as possible,
// so total duration must be less than 1 second
eg, ctx := errgroup.WithContext(context.Background())
startedAt := time.Now()
for range 10 {
eg.Go(func() error {
release, err := q.RequestArrival(ctx, "class1")
require.NoError(t, err)
time.Sleep(500 * time.Millisecond)
release()
return nil
})
}
require.NoError(t, eg.Wait())
require.True(t, time.Since(startedAt) <= 1*time.Second)
// 11 requests, limit = 10 RPS, so 10 requests should be
// scheduled as soon as possible, but last request should be
// scheduled at now + 1.0 s
eg, ctx = errgroup.WithContext(context.Background())
startedAt = time.Now()
for range 11 {
eg.Go(func() error {
release, err := q.RequestArrival(ctx, "class1")
require.NoError(t, err)
time.Sleep(500 * time.Millisecond)
release()
return nil
})
}
require.NoError(t, eg.Wait())
require.True(t, time.Since(startedAt) >= 1500*time.Millisecond)
require.True(t, time.Since(startedAt) <= 1600*time.Millisecond) // 100 ms offset to complete all requests
}
func TestMClockRestictTagRequests(t *testing.T) {
t.Parallel()
limit := 10.0
q, err := NewMClock(100, 100, map[string]TagInfo{
"class1": {Share: 50, LimitIOPS: &limit},
"class2": {Share: 50, LimitIOPS: &limit, Prohibited: true},
}, 5*time.Second)
require.NoError(t, err)
defer q.Close()
release, err := q.RequestArrival(context.Background(), "class1")
require.NoError(t, err)
release()
release, err = q.RequestArrival(context.Background(), "class2")
require.ErrorIs(t, err, ErrTagRequestsProhibited)
require.Nil(t, release)
}