roachtest: re-enable perturbation/full tests

The following tests were previously skipped via #149662 to focus on
stabilizing one test at a time:

- perturbation/full/intents
- perturbation/full/decommission
- perturbation/full/elasticWorkload
- perturbation/full/partition
- perturbation/full/slowDisk
- perturbation/full/addNode

Re-enable all of them. The metamorphic and dev variants remain
unchanged.

All re-enabled tests use the lenient defaultThresholds() (1.25x
throughput floor, p99/p50 disabled) for both the perturbation and
recovery intervals, with one exception: the partition test isolates an
entire region (4 of 12 nodes) and removes 1/3 of leaseholders, which
causes foreground throughput to drop sharply (~2x) while the partition
is in effect. The meaningful pass/fail signal for partition is whether
the cluster returns to baseline once the partition heals, so the
perturbation interval is left ungated (noImpactThresholds()) and the
1.25x floor is enforced only on the recovery interval, via the
recoveryImpact field.

While here, add a comment to slowDisk explaining why the default
threshold is appropriate for the full variant: with walFailover=true
and 2 disks per node, raft log writes fail over to the non-throttled
store and foreground throughput stays close to baseline. The lenient
1.25x floor is mainly to absorb noise from the slowLiveness leg.

Resolves: #149662
Epic: none

Release note: None

Author: tbg

pkg/cmd/roachtest/tests/perturbation/framework.go

@@ -419,7 +419,6 @@ func register(r registry.Registry, p perturbation, skipReason string) {
 
 func RegisterTests(r registry.Registry) {
 	const notSkipped = ""
-	const skippedByBankruptcy = "#149662"
 
 	register(r, restart{}, notSkipped)
 	addLong(r, restart{})
@@ -431,17 +430,13 @@ func RegisterTests(r registry.Registry) {
 	for _, asleep := range []bool{true, false} {
 		register(r, splits{asleep: asleep}, notSkipped)
 	}
-
-	// TODO(ssd): We skipped the majority of these tests so that we can focus on
-	// one at a time. These are vaguely ordered by their previous pass rate
-	// (highest first).
-	register(r, intents{}, skippedByBankruptcy)
-	register(r, decommission{}, skippedByBankruptcy)
-	register(r, elasticWorkload{}, skippedByBankruptcy)
-	register(r, partition{}, skippedByBankruptcy)
+	register(r, intents{}, notSkipped)
+	register(r, decommission{}, notSkipped)
+	register(r, elasticWorkload{}, notSkipped)
+	register(r, partition{}, notSkipped)
 	register(r, backfill{}, notSkipped)
-	register(r, &slowDisk{}, skippedByBankruptcy)
-	register(r, addNode{}, skippedByBankruptcy)
+	register(r, &slowDisk{}, notSkipped)
+	register(r, addNode{}, notSkipped)
 }
 
 func (v variations) makeClusterSpec() spec.ClusterSpec {

pkg/cmd/roachtest/tests/perturbation/network_partition.go

@@ -31,7 +31,13 @@ var _ perturbation = partition{}
 
 func (p partition) setup() variations {
 	p.partitionSite = true
-	v := setup(p, defaultThresholds())
+	// The partition test isolates an entire region (4 of 12 nodes), removing
+	// 1/3 of leaseholders. Foreground throughput naturally drops sharply
+	// while the partition is in effect, and the meaningful pass/fail signal
+	// is whether the cluster returns to baseline once the partition heals.
+	// Skip the perturbation-interval gate; keep the default recovery gate.
+	v := setup(p, noImpactThresholds())
+	v.recoveryImpact = defaultThresholds()
 	v.leaseType = registry.ExpirationLeases
 	// TODO(baptist): Remove this setting once #120073 is fixed.
 	v.clusterSettings["kv.lease.reject_on_leader_unknown.enabled"] = "true"

pkg/cmd/roachtest/tests/perturbation/slow_disk.go

@@ -32,6 +32,15 @@ var _ perturbation = &slowDisk{}
 func (s *slowDisk) setup() variations {
 	s.slowLiveness = true
 	s.walFailover = true
+	// With walFailover=true and 2 disks per node (the default for the full
+	// variant), raft log writes fail over to the non-throttled store, so
+	// foreground throughput is expected to stay close to baseline even
+	// while the staller is active. Default thresholds apply to both
+	// intervals; we keep the 1.25x floor (rather than tightening) only to
+	// avoid flakes from the slowLiveness leg, which routes liveness
+	// heartbeats through the slow disk. The metamorphic variant exercises
+	// configurations where walFailover is off and throughput can drop
+	// substantially -- those should override impact independently.
 	return setup(s, defaultThresholds())
 }