Recommend default_toast_compression=lz4 & jit=off

- Added to "misc" group
- Only provide recommendation on supported versions

Author: matthewmcnew

pkg/pgtune/misc.go

@@ -20,6 +20,10 @@ const (
 	AutovacuumNaptimeKey    = "autovacuum_naptime"
 	EffectiveIOKey          = "effective_io_concurrency" // linux only
 
+	// nonnumeric
+	DefaultToastCompression = "default_toast_compression"
+	Jit                     = "jit"
+
 	checkpointDefault           = "0.9"
 	statsTargetDefault          = "100"
 	randomPageCostDefault       = "1.1"
@@ -31,6 +35,8 @@ const (
 	// https://www.postgresql.org/message-id/20210422195232.GA25061%40momjian.us
 	effectiveIODefaultOldVersions = "200"
 	effectiveIODefault            = "256"
+	lz4Compression                = "lz4"
+	off                           = "off"
 
 	// If you want to lower this value, consider that Patroni will not accept anything less than 25 as
 	// a valid max_connections and will replace it with 100, per
@@ -59,12 +65,18 @@ func getMaxConns(totalMemory uint64) uint64 {
 	}
 }
 
+func getValueForVersion(currentVersion string, oldVersions []string, oldVersionValue, newVersionValue string) string {
+	for _, ov := range oldVersions {
+		if ov == currentVersion {
+			return oldVersionValue
+		}
+	}
+	return newVersionValue
+}
+
 func getEffectiveIOConcurrency(pgMajorVersion string) string {
 	switch pgMajorVersion {
-	case pgutils.MajorVersion96,
-		pgutils.MajorVersion10,
-		pgutils.MajorVersion11,
-		pgutils.MajorVersion12:
+	case pgutils.MajorVersion96, pgutils.MajorVersion10, pgutils.MajorVersion11, pgutils.MajorVersion12:
 		return effectiveIODefaultOldVersions
 	}
 	return effectiveIODefault
@@ -90,7 +102,10 @@ var MiscKeys = []string{
 	MaxLocksPerTxKey,
 	AutovacuumMaxWorkersKey,
 	AutovacuumNaptimeKey,
-	EffectiveIOKey,
+	DefaultToastCompression,
+	Jit,
+
+	EffectiveIOKey, //linux only
 }
 
 // MiscRecommender gives recommendations for MiscKeys based on system resources.
@@ -113,37 +128,49 @@ func (r *MiscRecommender) IsAvailable() bool {
 // Recommend returns the recommended PostgreSQL formatted value for the conf
 // file for a given key.
 func (r *MiscRecommender) Recommend(key string) string {
-	var val string
-	if key == CheckpointKey {
-		val = checkpointDefault
-	} else if key == StatsTargetKey {
-		val = statsTargetDefault
-	} else if key == MaxConnectionsKey {
-		conns := getMaxConns(r.totalMemory)
+	switch key {
+	case CheckpointKey:
+		return checkpointDefault
+	case StatsTargetKey:
+		return statsTargetDefault
+	case AutovacuumMaxWorkersKey:
+		return autovacuumMaxWorkersDefault
+	case AutovacuumNaptimeKey:
+		return autovacuumNaptimeDefault
+	case RandomPageCostKey:
+		return randomPageCostDefault
+	case EffectiveIOKey:
+		return getValueForVersion(r.pgMajorVersion, []string{
+			pgutils.MajorVersion96, pgutils.MajorVersion10, pgutils.MajorVersion11, pgutils.MajorVersion12},
+			effectiveIODefaultOldVersions, effectiveIODefault,
+		)
+	case DefaultToastCompression:
+		return getValueForVersion(r.pgMajorVersion, []string{
+			pgutils.MajorVersion96, pgutils.MajorVersion10, pgutils.MajorVersion11, pgutils.MajorVersion12, pgutils.MajorVersion13},
+			NoRecommendation, lz4Compression,
+		)
+	case Jit:
+		return getValueForVersion(r.pgMajorVersion, []string{
+			pgutils.MajorVersion96, pgutils.MajorVersion10, pgutils.MajorVersion11},
+			NoRecommendation, off,
+		)
+	case MaxConnectionsKey:
 		if r.maxConns != 0 {
-			conns = r.maxConns
+			return fmt.Sprintf("%d", r.maxConns)
 		}
-		val = fmt.Sprintf("%d", conns)
-	} else if key == RandomPageCostKey {
-		val = randomPageCostDefault
-	} else if key == MaxLocksPerTxKey {
+		return fmt.Sprintf("%d", getMaxConns(r.totalMemory))
+	case MaxLocksPerTxKey:
 		for i := len(maxLocksValues) - 1; i >= 1; i-- {
 			limit := uint64(math.Pow(2.0, float64(2+i)))
 			if r.totalMemory >= limit*parse.Gigabyte {
 				return maxLocksValues[i]
 			}
 		}
 		return maxLocksValues[0]
-	} else if key == AutovacuumMaxWorkersKey {
-		val = autovacuumMaxWorkersDefault
-	} else if key == AutovacuumNaptimeKey {
-		val = autovacuumNaptimeDefault
-	} else if key == EffectiveIOKey {
-		val = getEffectiveIOConcurrency(r.pgMajorVersion)
-	} else {
-		val = NoRecommendation
 	}
-	return val
+
+	//unknown key no recommendation
+	return NoRecommendation
 }
 
 // MiscSettingsGroup is the SettingsGroup to represent settings that do not fit in other SettingsGroups.

pkg/pgtune/misc_test.go

@@ -147,6 +147,68 @@ func TestGetEffectiveIOConcurrency(t *testing.T) {
 	}
 }
 
+func TestDefaultToastCompression(t *testing.T) {
+	cases := []struct {
+		pgMajorVersions []string
+		want            string
+	}{
+		{
+			[]string{pgutils.MajorVersion96, pgutils.MajorVersion10, pgutils.MajorVersion11, pgutils.MajorVersion12, pgutils.MajorVersion13},
+			NoRecommendation,
+		},
+		{
+			[]string{pgutils.MajorVersion14, pgutils.MajorVersion15, pgutils.MajorVersion16, pgutils.MajorVersion17,
+				"18", //future versions
+			},
+			"lz4",
+		},
+	}
+	for _, c := range cases {
+		for _, v := range c.pgMajorVersions {
+			t.Run("default_toast_compression:"+v, func(t *testing.T) {
+				r := NewMiscRecommender(1000, 32, v)
+
+				rec := r.Recommend(DefaultToastCompression)
+				if rec != c.want {
+					t.Errorf("wanted %s got: %s", c.want, rec)
+				}
+
+			})
+		}
+	}
+}
+
+func TestJIT(t *testing.T) {
+	cases := []struct {
+		pgMajorVersions []string
+		want            string
+	}{
+		{
+			[]string{pgutils.MajorVersion96, pgutils.MajorVersion10, pgutils.MajorVersion11},
+			NoRecommendation,
+		},
+		{
+			[]string{pgutils.MajorVersion12, pgutils.MajorVersion13, pgutils.MajorVersion14, pgutils.MajorVersion15, pgutils.MajorVersion16, pgutils.MajorVersion17,
+				"18", //future versions
+			},
+			"off",
+		},
+	}
+	for _, c := range cases {
+		for _, v := range c.pgMajorVersions {
+			t.Run("default_toast_compression:"+v, func(t *testing.T) {
+				r := NewMiscRecommender(1000, 32, v)
+
+				rec := r.Recommend(Jit)
+				if rec != c.want {
+					t.Errorf("wanted %s got: %s", c.want, rec)
+				}
+
+			})
+		}
+	}
+}
+
 func TestNewMiscRecommender(t *testing.T) {
 	for i := 0; i < 1000000; i++ {
 		mem := rand.Uint64()
@@ -173,7 +235,7 @@ func TestNewMiscRecommender(t *testing.T) {
 func TestMiscRecommenderRecommend(t *testing.T) {
 	for totalMemory, outerMatrix := range miscSettingsMatrix {
 		for maxConns, matrix := range outerMatrix {
-			r := &MiscRecommender{totalMemory, maxConns, pgutils.MajorVersion12}
+			r := &MiscRecommender{totalMemory, maxConns, pgutils.MajorVersion10}
 			testRecommender(t, r, MiscKeys, matrix)
 		}
 	}

pkg/tstune/tuner.go

@@ -444,26 +444,35 @@ func checkIfShouldShowSetting(keys []string, parseResults map[string]*tunablePar
 
 		rv := pgtune.GetFloatParser(recommender)
 
+		// get and parse our recommendation; fail if for we can't
+		rec := recommender.Recommend(k)
+
+		switch {
+		case rec == pgtune.NoRecommendation:
+			// don't bother adding it to the map. no recommendation
+			continue
+		case r.commented:
+			show[k] = true
+		case r.value == rec:
+			// don't bother adding it to the map. no recommendation
+			continue
+
+		}
+
 		// parse the value already there; if unparseable, should show our rec
 		curr, err := rv.ParseFloat(k, r.value)
 		if err != nil {
 			show[k] = true
 			continue
 		}
 
-		// get and parse our recommendation; fail if for we can't
-		rec := recommender.Recommend(k)
-		if rec == pgtune.NoRecommendation {
-			// don't bother adding it to the map. no recommendation
-			continue
-		}
 		target, err := rv.ParseFloat(k, rec)
 		if err != nil {
 			return nil, fmt.Errorf("unexpected parsing problem: %v", err)
 		}
 
 		// only show if our recommendation is significantly different, or config is commented
-		if !isCloseEnough(curr, target, fudgeFactor) || r.commented {
+		if !isCloseEnough(curr, target, fudgeFactor) {
 			show[k] = true
 		}
 	}