From 97be5573aff20600cc35e582415fffab73a0e3e6 Mon Sep 17 00:00:00 2001
From: buffer <1045931706@qq.com>
Date: Fri, 22 Jul 2022 14:39:09 +0800
Subject: [PATCH] core:  clean some remain code about deviation filter. (#5329)

close tikv/pd#5328

Signed-off-by: bufferflies <1045931706@qq.com>
---
 server/core/store_stats.go            | 28 ++-------------------------
 server/core/store_stats_test.go       |  3 ---
 server/statistics/store_collection.go |  2 --
 3 files changed, 2 insertions(+), 31 deletions(-)

diff --git a/server/core/store_stats.go b/server/core/store_stats.go
index 2cc8099ce49..2416c4c4678 100644
--- a/server/core/store_stats.go
+++ b/server/core/store_stats.go
@@ -15,8 +15,6 @@
 package core
 
 import (
-	"math"
-
 	"github.com/pingcap/kvproto/pkg/pdpb"
 	"github.com/tikv/pd/pkg/movingaverage"
 	"github.com/tikv/pd/pkg/syncutil"
@@ -28,20 +26,12 @@ type storeStats struct {
 
 	// avgAvailable is used to make available smooth, aka no sudden changes.
 	avgAvailable *movingaverage.HMA
-	// Following two fields are used to trace the deviation when available
-	// records' deviation range to make scheduling able to converge.
-	// Here `MaxFilter` is used to make the scheduling more conservative, and
-	// `HMA` is used to make it smooth.
-	maxAvailableDeviation    *movingaverage.MaxFilter
-	avgMaxAvailableDeviation *movingaverage.HMA
 }
 
 func newStoreStats() *storeStats {
 	return &storeStats{
-		rawStats:                 &pdpb.StoreStats{},
-		avgAvailable:             movingaverage.NewHMA(60),        // take 10 minutes sample under 10s heartbeat rate
-		maxAvailableDeviation:    movingaverage.NewMaxFilter(120), // take 20 minutes sample under 10s heartbeat rate
-		avgMaxAvailableDeviation: movingaverage.NewHMA(60),        // take 10 minutes sample under 10s heartbeat rate
+		rawStats:     &pdpb.StoreStats{},
+		avgAvailable: movingaverage.NewHMA(60), // take 10 minutes sample under 10s heartbeat rate
 	}
 }
 
@@ -53,11 +43,7 @@ func (ss *storeStats) updateRawStats(rawStats *pdpb.StoreStats) {
 	if ss.avgAvailable == nil {
 		return
 	}
-
 	ss.avgAvailable.Add(float64(rawStats.GetAvailable()))
-	deviation := math.Abs(float64(rawStats.GetAvailable()) - ss.avgAvailable.Get())
-	ss.maxAvailableDeviation.Add(deviation)
-	ss.avgMaxAvailableDeviation.Add(ss.maxAvailableDeviation.Get())
 }
 
 // GetStoreStats returns the statistics information of the store.
@@ -157,16 +143,6 @@ func (ss *storeStats) GetAvgAvailable() uint64 {
 	return climp0(ss.avgAvailable.Get())
 }
 
-// GetAvailableDeviation returns approximate magnitude of available in the recent period.
-func (ss *storeStats) GetAvailableDeviation() uint64 {
-	ss.mu.RLock()
-	defer ss.mu.RUnlock()
-	if ss.avgMaxAvailableDeviation == nil {
-		return 0
-	}
-	return climp0(ss.avgMaxAvailableDeviation.Get())
-}
-
 func climp0(v float64) uint64 {
 	if v <= 0 {
 		return 0
diff --git a/server/core/store_stats_test.go b/server/core/store_stats_test.go
index bf12e12d78c..9f2969cd81f 100644
--- a/server/core/store_stats_test.go
+++ b/server/core/store_stats_test.go
@@ -36,7 +36,6 @@ func TestStoreStats(t *testing.T) {
 	re.Equal(uint64(50*units.GiB), store.GetUsedSize())
 	re.Equal(uint64(150*units.GiB), store.GetAvailable())
 	re.Equal(uint64(150*units.GiB), store.GetAvgAvailable())
-	re.Equal(uint64(0), store.GetAvailableDeviation())
 
 	store = store.Clone(SetStoreStats(&pdpb.StoreStats{
 		Capacity:  uint64(200 * units.GiB),
@@ -47,6 +46,4 @@ func TestStoreStats(t *testing.T) {
 	re.Equal(uint64(160*units.GiB), store.GetAvailable())
 	re.Greater(store.GetAvgAvailable(), uint64(150*units.GiB))
 	re.Less(store.GetAvgAvailable(), uint64(160*units.GiB))
-	re.Greater(store.GetAvailableDeviation(), uint64(0))
-	re.Less(store.GetAvailableDeviation(), uint64(10*units.GiB))
 }
diff --git a/server/statistics/store_collection.go b/server/statistics/store_collection.go
index aa98561c044..416d23916cb 100644
--- a/server/statistics/store_collection.go
+++ b/server/statistics/store_collection.go
@@ -119,8 +119,6 @@ func (s *storeStatistics) Observe(store *core.StoreInfo, stats *StoresStats) {
 	storeStatusGauge.WithLabelValues(storeAddress, id, "store_available").Set(float64(store.GetAvailable()))
 	storeStatusGauge.WithLabelValues(storeAddress, id, "store_used").Set(float64(store.GetUsedSize()))
 	storeStatusGauge.WithLabelValues(storeAddress, id, "store_capacity").Set(float64(store.GetCapacity()))
-	storeStatusGauge.WithLabelValues(storeAddress, id, "store_available_avg").Set(float64(store.GetAvgAvailable()))
-	storeStatusGauge.WithLabelValues(storeAddress, id, "store_available_deviation").Set(float64(store.GetAvailableDeviation()))
 
 	// Store flows.
 	storeFlowStats := stats.GetRollingStoreStats(store.GetID())