roachtest: enable schema changes in acceptance/version-upgrade

Previously, due to flakes we disabled schema changes inside
the version update test. This patch re-enables them, since
we are confident that the workload itslef is now stable in a
mixed version state.

Fixes: cockroachdb#58489
Release note: None

pkg/cmd/roachtest/roachtestutil/mixedversion/runner.go

@@ -476,6 +476,21 @@ func (h *Helper) Exec(rng *rand.Rand, query string, args ...interface{}) error {
 	return err
 }
 
+// Run performs `cluster.RunE` on a randomly picked node.
+func (h *Helper) Run(rng *rand.Rand, cmd ...string) error {
+	node := h.runner.crdbNodes[rng.Intn(len(h.runner.crdbNodes))]
+	h.stepLogger.Printf("executing command:\n%s\nNode: %v", cmd, node)
+	return h.runner.cluster.RunE(h.ctx, option.NodeListOption{node}, cmd...)
+}
+
+// InitLegacyWorkload initializes a legacy workload on all nodes.
+func (h *Helper) InitLegacyWorkload(workloadPath string, workload string) {
+	// Stage workload on all nodes as the load node to run workload is chosen
+	// randomly.
+	h.runner.cluster.Put(h.ctx, workloadPath, "./workload", h.runner.crdbNodes)
+	h.runner.cluster.Run(h.ctx, h.runner.crdbNodes, "./workload init", workload)
+}
+
 func (h *Helper) Connect(node int) *gosql.DB {
 	return h.runner.conn(node)
 }

pkg/cmd/roachtest/tests/versionupgrade.go

@@ -17,6 +17,7 @@ import (
 	"math/rand"
 	"path/filepath"
 	"runtime"
+	"sync"
 	"time"
 
 	"github.com/cockroachdb/cockroach/pkg/cmd/roachtest/cluster"
@@ -102,7 +103,7 @@ func runVersionUpgrade(ctx context.Context, t test.Test, c cluster.Cluster) {
 	if c.IsLocal() && runtime.GOARCH == "arm64" {
 		t.Skip("Skip under ARM64. See https://github.com/cockroachdb/cockroach/issues/89268")
 	}
-
+	initWorkload := sync.Once{}
 	mvt := mixedversion.NewTest(ctx, t, t.L(), c, c.All())
 	mvt.InMixedVersion("run backup", func(ctx context.Context, l *logger.Logger, rng *rand.Rand, h *mixedversion.Helper) error {
 		// Verify that backups can be created in various configurations. This is
@@ -126,6 +127,22 @@ func runVersionUpgrade(ctx context.Context, t test.Test, c cluster.Cluster) {
 			return nil
 		},
 	)
+	mvt.InMixedVersion(
+		"test schema change step",
+		func(ctx context.Context, l *logger.Logger, rng *rand.Rand, h *mixedversion.Helper) error {
+			initWorkload.Do(func() {
+				h.InitLegacyWorkload(t.DeprecatedWorkload(), "schemachange")
+			})
+			l.Printf("running schema workload step")
+			runCmd := []string{
+				"./workload run schemachange --verbose=1",
+				fmt.Sprintf("--max-ops %d", 10),
+				fmt.Sprintf("--concurrency %d", 2),
+				fmt.Sprintf("{pgurl:1-%d}", len(c.All())),
+			}
+			return h.Run(rng, runCmd...)
+		},
+	)
 	mvt.AfterUpgradeFinalized(
 		"check if GC TTL is pinned",
 		func(ctx context.Context, l *logger.Logger, rng *rand.Rand, h *mixedversion.Helper) error {