asim: enable random zone config event generation

Previously, zone config event generation used hardcoded span configurations.
This limits our ability to test the allocator more thoroughly.

To improve this, this patch enables random span configs to be generated and
applied as part of the simulation. These configurations are generated by
randomly selecting the primary region, region V.S. zone survival goal, and
leaseholder preference.

```
The following command is now supported:
"rand_events" [cycle_via_random_survival_goals]
```

Part of: #106192
Release Note: none
Epic: none

pkg/kv/kvserver/asim/tests/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
         "output.go",
         "rand_framework.go",
         "rand_gen.go",
+        "rand_util.go",
     ],
     importpath = "github.com/cockroachdb/cockroach/pkg/kv/kvserver/asim/tests",
     visibility = ["//visibility:public"],
@@ -20,6 +21,10 @@ go_library(
         "//pkg/kv/kvserver/asim/scheduled",
         "//pkg/kv/kvserver/asim/state",
         "//pkg/roachpb",
+        "//pkg/sql",
+        "//pkg/sql/catalog/catpb",
+        "//pkg/sql/catalog/descpb",
+        "//pkg/sql/catalog/multiregion",
     ],
 )
 

pkg/kv/kvserver/asim/tests/rand_framework.go

@@ -269,7 +269,9 @@ func (f randTestingFramework) randomEventSeriesGen(
 ) gen.StaticEvents {
 	switch eventsType := f.s.eventGen.eventsType; eventsType {
 	case cycleViaHardcodedSurvivalGoals:
-		return generateSurvivalGoalsEvents(cluster.Regions(), settings.Settings.StartTime, f.s.eventGen.durationToAssertOnEvent)
+		return generateHardcodedSurvivalGoalsEvents(cluster.Regions(), settings.Settings.StartTime, f.s.eventGen.durationToAssertOnEvent)
+	case cycleViaRandomSurvivalGoals:
+		return generateRandomSurvivalGoalsEvents(cluster.Regions(), settings.Settings.StartTime, f.s.eventGen.durationToAssertOnEvent, f.s.duration, f.s.randSource)
 	default:
 		panic("unknown event series type")
 	}

pkg/kv/kvserver/asim/tests/rand_gen.go

@@ -22,6 +22,10 @@ import (
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/asim/gen"
 	"github.com/cockroachdb/cockroach/pkg/kv/kvserver/asim/state"
 	"github.com/cockroachdb/cockroach/pkg/roachpb"
+	"github.com/cockroachdb/cockroach/pkg/sql"
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog/catpb"
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog/descpb"
+	"github.com/cockroachdb/cockroach/pkg/sql/catalog/multiregion"
 )
 
 // randomClusterInfoGen returns a randomly picked predefined configuration.
@@ -272,6 +276,9 @@ const (
 	// Cycle through predefined region and zone survival configurations. Note
 	// that only cluster_gen_type=multi_region can execute this event.
 	cycleViaHardcodedSurvivalGoals eventSeriesType = iota
+	// Cycle through randomly generated region and zone survival configurations.
+	// Note that only cluster_gen_type=multi_region can execute this event.
+	cycleViaRandomSurvivalGoals
 )
 
 type eventGenSettings struct {
@@ -288,6 +295,8 @@ func (e eventSeriesType) String() string {
 	switch e {
 	case cycleViaHardcodedSurvivalGoals:
 		return "cycle_via_hardcoded_survival_goals"
+	case cycleViaRandomSurvivalGoals:
+		return "cycle_via_random_survival_goals"
 	default:
 		panic("unknown event series type")
 	}
@@ -297,6 +306,8 @@ func getEventSeriesType(s string) eventSeriesType {
 	switch s {
 	case "cycle_via_hardcoded_survival_goals":
 		return cycleViaHardcodedSurvivalGoals
+	case "cycle_via_random_survival_goals":
+		return cycleViaRandomSurvivalGoals
 	default:
 		panic(fmt.Sprintf("unknown event series type: %s", s))
 	}
@@ -327,7 +338,12 @@ func constructSetZoneConfigEventWithConformanceAssertion(
 	}
 }
 
-func generateSurvivalGoalsEvents(
+// generateHardcodedSurvivalGoalsEvents sets up two MutationWithAssertionEvents.
+// The first mutation event starts at the beginning, followed by an assertion
+// event after some time (durationToAssert). Right after that, the second
+// MutationWithAssertionEvent happens. Both of these mutation events are
+// SetSpanConfig events which use two hardcoded zone configurations.
+func generateHardcodedSurvivalGoalsEvents(
 	regions []state.Region, startTime time.Time, durationToAssert time.Duration,
 ) gen.StaticEvents {
 	if len(regions) < 3 {
@@ -354,3 +370,88 @@ func generateSurvivalGoalsEvents(
 	}
 	return eventGen
 }
+
+// getRegionNames takes a list of regions and returns the extracted region names
+// in the catpb.RegionNames format.
+func getRegionNames(regions []state.Region) (regionNames catpb.RegionNames) {
+	for _, r := range regions {
+		regionNames = append(regionNames, catpb.RegionName(r.Name))
+	}
+	return regionNames
+}
+
+// randomlySelectSurvivalGoal randomly selects between SurvivalGoal_ZONE_FAILURE
+// and SurvivalGoal_REGION_FAILURE.
+func randomlySelectSurvivalGoal(randSource *rand.Rand) descpb.SurvivalGoal {
+	if randBool(randSource) {
+		return descpb.SurvivalGoal_ZONE_FAILURE
+	} else {
+		return descpb.SurvivalGoal_REGION_FAILURE
+	}
+}
+
+// randomlySelectDataPlacement randomly selects between DataPlacement_DEFAULT
+// and DataPlacement_RESTRICTED.
+func randomlySelectDataPlacement(randSource *rand.Rand) descpb.DataPlacement {
+	if randBool(randSource) {
+		return descpb.DataPlacement_DEFAULT
+	} else {
+		return descpb.DataPlacement_RESTRICTED
+	}
+}
+
+// generateRandomSurvivalGoalsEvents generates SetSpanConfig events spaced at
+// intervals defined by durationToAssert from the start time. These events apply
+// a randomly generated zone configuration followed by an assertion event. Note
+// that these random configurations might be unsatisfiable under the cluster
+// setup.
+func generateRandomSurvivalGoalsEvents(
+	regions []state.Region,
+	startTime time.Time,
+	durationToAssert time.Duration,
+	duration time.Duration,
+	randSource *rand.Rand,
+) gen.StaticEvents {
+	if len(regions) < 3 {
+		panic("iterate all zone configs is only possible for clusters with > 3 regions")
+	}
+	eventGen := gen.NewStaticEventsWithNoEvents()
+	delay := time.Duration(0)
+
+	span := roachpb.Span{
+		Key:    state.MinKey.ToRKey().AsRawKey(),
+		EndKey: state.MaxKey.ToRKey().AsRawKey(),
+	}
+
+	regionNames := getRegionNames(regions)
+	for delay < duration {
+		randomRegionIndex := randIndex(randSource, len(regions))
+		randomPrimaryRegion := regions[randomRegionIndex].Name
+		randomSurvivalGoal := randomlySelectSurvivalGoal(randSource)
+		randomDataPlacement := randomlySelectDataPlacement(randSource)
+		rc := multiregion.MakeRegionConfig(
+			regionNames,
+			catpb.RegionName(randomPrimaryRegion),
+			randomSurvivalGoal,
+			descpb.InvalidID,
+			randomDataPlacement,
+			nil,
+			descpb.ZoneConfigExtensions{},
+		)
+
+		zoneConfig, convertErr := sql.TestingConvertRegionToZoneConfig(rc)
+		if convertErr != nil {
+			panic(fmt.Sprintf("failed to convert region to zone config %s", convertErr.Error()))
+		}
+		if validateErr := zoneConfig.Validate(); validateErr != nil {
+			panic(fmt.Sprintf("zone config generated is invalid %s", validateErr.Error()))
+		}
+		if validateErr := zoneConfig.EnsureFullyHydrated(); validateErr != nil {
+			panic(fmt.Sprintf("zone config generated is not fully hydrated %s", validateErr.Error()))
+		}
+		eventGen.ScheduleMutationWithAssertionEvent(startTime, delay,
+			constructSetZoneConfigEventWithConformanceAssertion(span, zoneConfig, durationToAssert))
+		delay += durationToAssert
+	}
+	return eventGen
+}

pkg/kv/kvserver/asim/tests/rand_test.go

@@ -137,7 +137,8 @@ const (
 //	- height (default value is 15): height of the plot
 //	- width (default value is 80): width of the plot
 
-//  5. "rand_events" [type=<string>{cycle_via_hardcoded_survival_goals}]
+//  5. "rand_events" [type=<string>{cycle_via_hardcoded_survival_goals,
+//  cycle_via_random_survival_goals}]
 //  [duration_to_assert_on_event=<time.Duration>]
 //  e.g. rand_events type=cycle_via_hardcoded_survival_goals duration=5m
 //  - rand_events: generates interesting event series to be scheduled in the

pkg/kv/kvserver/asim/tests/rand_util.go

@@ -0,0 +1,29 @@
+// Copyright 2023 The Cockroach Authors.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+package tests
+
+import "math/rand"
+
+// randBool randomly picks between true and false.
+func randBool(randSource *rand.Rand) bool {
+	return randSource.Intn(2) == 0
+}
+
+// randBetweenMinMaxExclusive randomly selects a number∈[min, max).
+func randBetweenMinMaxExclusive(randSource *rand.Rand, min int, max int) int {
+	return randSource.Intn(max-min) + min
+}
+
+// randIndex randomly selects an index given the length of an array ∈[0,
+// lenOfArr).
+func randIndex(randSource *rand.Rand, lenOfArr int) int {
+	return randBetweenMinMaxExclusive(randSource, 0, lenOfArr)
+}

pkg/kv/kvserver/asim/tests/testdata/rand/rand_event

@@ -0,0 +1,131 @@
+rand_cluster cluster_gen_type=multi_region
+----
+
+change_static_option ranges=1
+----
+
+rand_events type=cycle_via_random_survival_goals duration_to_assert_on_event=5m
+----
+
+eval duration=60m num_iterations=1 verbose=(all)
+----
+test settings
+	num_iterations=1 duration=1h0m0s
+----------------------------------
+generating cluster configurations using randomized option
+	cluster_gen_type=multi_region
+generating ranges configurations using static option
+	placement_type=even, ranges=1, key_space=200000, replication_factor=3, bytes=0
+generating load configurations using static option
+	rw_ratio=0.00, rate=0.00, min_block=1, max_block=1, min_key=1, max_key=200000, skewed_access=false
+generating events configurations using randomized option
+	duration_to_assert_on_event=5m0s, type=cycle_via_random_survival_goals
+generating settings configurations using static option
+----------------------------------
+sample1: start running
+configurations generated using seed 7894140303635748408
+	loaded cluster with
+ 		region:US_East [zone=US_East_1(nodes=1,stores=0), zone=US_East_2(nodes=2,stores=0), zone=US_East_3(nodes=3,stores=0), zone=US_East_3(nodes=10,stores=0)]
+		region:US_West [zone=US_West_1(nodes=2,stores=0)]
+		region:EU [zone=EU_1(nodes=3,stores=0), zone=EU_2(nodes=3,stores=0), zone=EU_3(nodes=4,stores=0)]
+	basic ranges with placement_type=even, ranges=1, key_space=200000, replication_factor=3, bytes=0
+	basic load with rw_ratio=0.00, rate=0.00, skewed_access=false, min_block_size=1, max_block_size=1, min_key=1, max_key=200000
+	number of mutation events=12, number of assertion events=12
+initial state at 2022-03-21 11:00:00:
+	stores(28)=[s1n1=(replicas(0)),s2n2=(replicas(0)),s3n3=(replicas(0)),s4n4=(replicas(1)),s5n5=(replicas(0)),s6n6=(replicas(0)),s7n7=(replicas(0)),s8n8=(replicas(0)),s9n9=(replicas(0)),s10n10=(replicas(0)),s11n11=(replicas(0)),s12n12=(replicas(0)),s13n13=(replicas(0)),s14n14=(replicas(0)),s15n15=(replicas(0)),s16n16=(replicas(0)),s17n17=(replicas(1)),s18n18=(replicas(0)),s19n19=(replicas(0)),s20n20=(replicas(0)),s21n21=(replicas(0)),s22n22=(replicas(1)),s23n23=(replicas(0)),s24n24=(replicas(0)),s25n25=(replicas(1)),s26n26=(replicas(1)),s27n27=(replicas(0)),s28n28=(replicas(0))]
+topology:
+EU
+  EU_1
+  │ └── [19 20 21]
+  EU_2
+  │ └── [22 23 24]
+  EU_3
+  │ └── [25 26 27 28]
+US_East
+  US_East_1
+  │ └── [1]
+  US_East_2
+  │ └── [2 3]
+  US_East_3
+  │ └── [4 5 6 7 8 9 10 11 12 13 14 15 16]
+US_West
+  US_West_1
+    └── [17 18]
+24 events executed:
+	executed at: 2022-03-21 11:00:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:3 constraints:<num_replicas:1 constraints:<key:"region" value:"US_East" > > constraints:<num_replicas:1 constraints:<key:"region" value:"US_West" > > constraints:<num_replicas:1 constraints:<key:"region" value:"EU" > > voter_constraints:<constraints:<key:"region" value:"EU" > > lease_preferences:<constraints:<key:"region" value:"EU" > > 
+	executed at: 2022-03-21 11:05:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:05:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:5 voter_constraints:<num_replicas:2 constraints:<key:"region" value:"US_West" > > lease_preferences:<constraints:<key:"region" value:"US_West" > > 
+	executed at: 2022-03-21 11:10:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:10:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:3 num_voters:3 voter_constraints:<constraints:<key:"region" value:"EU" > > lease_preferences:<constraints:<key:"region" value:"EU" > > 
+	executed at: 2022-03-21 11:15:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:15:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:5 voter_constraints:<num_replicas:2 constraints:<key:"region" value:"US_West" > > lease_preferences:<constraints:<key:"region" value:"US_West" > > 
+	executed at: 2022-03-21 11:20:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:20:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:3 num_voters:3 voter_constraints:<constraints:<key:"region" value:"US_West" > > lease_preferences:<constraints:<key:"region" value:"US_West" > > 
+	executed at: 2022-03-21 11:25:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			failed:   conformance unavailable=0 under=0 over=0 violating=0 
+  actual unavailable=0 under=0, over=0 violating=1
+violating constraints:
+  r1:{0000000000-9999999999} [(n17,s17):14, (n18,s18):13, (n22,s22):7] applying num_voters=3 voter_constraints=[+region=US_West] lease_preferences=[+region=US_West]
+	executed at: 2022-03-21 11:25:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:5 voter_constraints:<num_replicas:2 constraints:<key:"region" value:"EU" > > lease_preferences:<constraints:<key:"region" value:"EU" > > 
+	executed at: 2022-03-21 11:30:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:30:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:3 constraints:<num_replicas:1 constraints:<key:"region" value:"US_East" > > constraints:<num_replicas:1 constraints:<key:"region" value:"US_West" > > constraints:<num_replicas:1 constraints:<key:"region" value:"EU" > > voter_constraints:<constraints:<key:"region" value:"EU" > > lease_preferences:<constraints:<key:"region" value:"EU" > > 
+	executed at: 2022-03-21 11:35:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:35:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:5 constraints:<num_replicas:1 constraints:<key:"region" value:"US_East" > > constraints:<num_replicas:1 constraints:<key:"region" value:"US_West" > > constraints:<num_replicas:1 constraints:<key:"region" value:"EU" > > voter_constraints:<num_replicas:2 constraints:<key:"region" value:"US_West" > > lease_preferences:<constraints:<key:"region" value:"US_West" > > 
+	executed at: 2022-03-21 11:40:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:40:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:3 num_voters:3 voter_constraints:<constraints:<key:"region" value:"EU" > > lease_preferences:<constraints:<key:"region" value:"EU" > > 
+	executed at: 2022-03-21 11:45:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:45:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:5 constraints:<num_replicas:1 constraints:<key:"region" value:"US_East" > > constraints:<num_replicas:1 constraints:<key:"region" value:"US_West" > > constraints:<num_replicas:1 constraints:<key:"region" value:"EU" > > voter_constraints:<num_replicas:2 constraints:<key:"region" value:"US_West" > > lease_preferences:<constraints:<key:"region" value:"US_West" > > 
+	executed at: 2022-03-21 11:50:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:50:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:5 constraints:<num_replicas:1 constraints:<key:"region" value:"US_East" > > constraints:<num_replicas:1 constraints:<key:"region" value:"US_West" > > constraints:<num_replicas:1 constraints:<key:"region" value:"EU" > > voter_constraints:<num_replicas:2 constraints:<key:"region" value:"EU" > > lease_preferences:<constraints:<key:"region" value:"EU" > > 
+	executed at: 2022-03-21 11:55:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+	executed at: 2022-03-21 11:55:00
+		event: set span config event with span={0000000000-9999999999}, config=range_min_bytes:134217728 range_max_bytes:536870912 gc_policy:<ttl_seconds:14400 > num_replicas:5 num_voters:3 constraints:<num_replicas:1 constraints:<key:"region" value:"US_East" > > constraints:<num_replicas:1 constraints:<key:"region" value:"US_West" > > constraints:<num_replicas:1 constraints:<key:"region" value:"EU" > > voter_constraints:<constraints:<key:"region" value:"EU" > > lease_preferences:<constraints:<key:"region" value:"EU" > > 
+	executed at: 2022-03-21 12:00:00
+		event: assertion checking event
+			1. assertion=conformance unavailable=0 under=0 over=0 violating=0 
+			passed
+sample1: pass
+----------------------------------

pkg/sql/region_util.go

@@ -118,6 +118,25 @@ func makeRequiredConstraintForRegion(r catpb.RegionName) zonepb.Constraint {
 	}
 }
 
+// TestingConvertRegionToZoneConfig converts a given region config into a zone
+// configuration, ensuring the result is fully hydrated. Refer to the
+// zoneConfigForMultiRegionDatabase function for details on how the conversion
+// is made. Note that this should only be used for testing purposes.
+func TestingConvertRegionToZoneConfig(
+	regionConfig multiregion.RegionConfig,
+) (zonepb.ZoneConfig, error) {
+	zc, err := zoneConfigForMultiRegionDatabase(regionConfig)
+
+	// Hardcode settings based on DefaultZoneConfig() to ensure that generated
+	// zone configuration is fully hydrated for AsSpanConfig() conversion.
+	defaultZoneConfig := zonepb.DefaultZoneConfig()
+	zc.RangeMinBytes = defaultZoneConfig.RangeMinBytes
+	zc.RangeMaxBytes = defaultZoneConfig.RangeMaxBytes
+	zc.GC = defaultZoneConfig.GC
+	zc.NullVoterConstraintsIsEmpty = defaultZoneConfig.NullVoterConstraintsIsEmpty
+	return zc, err
+}
+
 // zoneConfigForMultiRegionDatabase generates a ZoneConfig stub for a
 // multi-region database such that at least one replica (voting or non-voting)
 // is constrained to each region defined within the given `regionConfig` and