asim: add tests for constraints validation, asim determinism

This patch adds an asim datadriven test case which sets up zone constraints and
ensures its proper application and validation of these constraints.

Part Of: cockroachdb#105904
Release Note: None

Author: wenyihu6

pkg/kv/kvserver/asim/asim_test.go

@@ -39,17 +39,18 @@ func TestRunAllocatorSimulator(t *testing.T) {
 	sim.RunSim(ctx)
 }
 
-func TestAllocatorSimulatorDeterministic(t *testing.T) {
-	skip.WithIssue(t, 105904, "asim is non-deterministic")
+func TestAsimDeterministic(t *testing.T) {
+	skip.UnderRace(t, 105904, "asim is non-deterministic under race")
 	settings := config.DefaultSimulationSettings()
 
 	runs := 3
 	duration := 15 * time.Minute
 	settings.TickInterval = 2 * time.Second
 
-	stores := 7
+	stores := 21
 	replsPerRange := 3
-	replicasPerStore := 100
+	replicasPerStore := 600
+
 	// NB: We want 100 replicas per store, so the number of ranges required
 	// will be 1/3 of the total replicas.
 	ranges := (replicasPerStore * stores) / replsPerRange

pkg/kv/kvserver/asim/tests/testdata/example_zone_config

@@ -0,0 +1,76 @@
+# This test applies a configuration that prioritizes zone constraints, favoring
+# the US_East region. As a result, we expect a majority of replicas to be
+# distributed across stores numbered 1-12, all within the US_East region. The
+# allocation of replicas to stores outside of this region is expected to be
+# zero.
+
+load_cluster config=multi_region
+----
+
+# Create 200 ranges (RF=3) with zone preference set to US_East.
+set_span_config delay=1m
+[0,9999999999): num_replicas=3 constraints={'+region=US_East'}
+----
+
+assertion type=conformance under=0 violating=0
+----
+
+gen_ranges ranges=200
+----
+
+# Stores=(13-25) should have number of replicas close to zero.
+assertion type=stat stat=replicas ticks=5 exact_bound=0 stores=(13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30)
+----
+
+eval duration=10m samples=1 seed=42
+----
+OK
+
+
+topology
+----
+EU
+  EU_1
+  │ └── [25 26 27 28]
+  EU_2
+  │ └── [29 30 31 32]
+  EU_3
+  │ └── [33 34 35 36]
+US_East
+  US_East_1
+  │ └── [1 2 3 4]
+  US_East_2
+  │ └── [5 6 7 8]
+  US_East_3
+  │ └── [9 10 11 12]
+US_West
+  US_West_1
+    └── [13 14 15 16]
+  US_West_2
+    └── [17 18 19 20]
+  US_West_3
+    └── [21 22 23 24]
+
+plot stat=replicas
+----
+----
+
+ 51.00 ┤               ╭╭──────────────────────────────────────────────────────────────
+ 47.60 ┤           ╭╮╭─╭╯─────╯────────────────────────────────────────────────────────
+ 44.20 ┤           │╭──╯
+ 40.80 ┤          ╭╭╯╯
+ 37.40 ┤         ╭─╯
+ 34.00 ┤         │─╯
+ 30.60 ┤         │╯
+ 27.20 ┤        ╭│
+ 23.80 ┤        ╭╯
+ 20.40 ┤        │╯
+ 17.00 ┼────────╮╮
+ 13.60 ┤        ╰╮╮
+ 10.20 ┤        ╰│╰╮╮
+  6.80 ┤         ╰─╮───╮
+  3.40 ┤         ╰╰╰───╮──────╮
+  0.00 ┤          ╰╰╰╰─╰───────────────────────────────────────────────────────────────
+                                            replicas
+----
+----