Parallelize integration tests (#9292)

## What changed?

Made integration tests run in parallel.

## Why?

Before: ~8min
[[run](https://github.com/temporalio/temporal/actions/runs/21930252400/job/63333789136#step:7:1)]
🐢
After: ~3m
[[run](https://github.com/temporalio/temporal/actions/runs/22114061618/job/63917852614?pr=9292)]
🐰

## How did you test it?
- [ ] built
- [ ] run locally and tested manually
- [x] covered by existing tests
- [ ] added new unit test(s)
- [ ] added new functional test(s)

## Potential risks

They are not known to be flaky; and anecdotally all passed on the first
run.

Author: stephanos

.github/workflows/linters.yml

@@ -128,6 +128,32 @@ jobs:
       - name: check yaml formatting
         run: make lint-yaml
 
+  parallelize-tests:
+    runs-on: ubuntu-24.04-arm
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-go@v6
+        with:
+          go-version-file: "go.mod"
+          check-latest: true
+          cache: true
+
+      - name: check test parallelization
+        run: make parallelize-tests
+
+      - name: check-is-dirty
+        run: |
+          if [[ -n $(git status --porcelain) ]]; then
+            echo "Detected uncommitted changes after running parallelize-tests."
+            echo "Run 'make parallelize-tests' locally and commit the changes."
+            git status
+            git diff
+            exit 1
+          fi
+
   golangci:
     runs-on: ubuntu-24.04-arm
     steps:
@@ -163,6 +189,7 @@ jobs:
       - fmt-imports
       - lint-yaml
       - golangci
+      - parallelize-tests
     runs-on: ubuntu-24.04-arm
     if: always()
     env:

Makefile

@@ -417,6 +417,10 @@ fmt-imports: $(GCI) # Don't get confused, there is a single linter called gci, w
 	@printf $(COLOR) "Formatting imports..."
 	@$(GCI) write --skip-generated -s standard -s default ./*
 
+parallelize-tests:
+	@printf $(COLOR) "Add t.Parallel() to tests..."
+	@go run ./cmd/tools/parallelize $(INTEGRATION_TEST_DIRS)
+
 fmt-yaml: $(YAMLFMT)
 	@printf $(COLOR) "Formatting YAML files..."
 	@$(YAMLFMT) -conf .github/.yamlfmt .

cmd/tools/parallelize/main.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"go.temporal.io/server/tools/parallelize"
+)
+
+func main() {
+	if err := parallelize.Main(); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+}

common/persistence/tests/cassandra_test.go

@@ -120,6 +120,7 @@ func (s *recordingSession) Query(query string, args ...any) gocql.Query {
 }
 
 func TestCassandraShardStoreSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -138,6 +139,7 @@ func TestCassandraShardStoreSuite(t *testing.T) {
 }
 
 func TestCassandraExecutionMutableStateStoreSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -161,6 +163,7 @@ func TestCassandraExecutionMutableStateStoreSuite(t *testing.T) {
 }
 
 func TestCassandraExecutionMutableStateTaskStoreSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -186,6 +189,7 @@ func TestCassandraExecutionMutableStateTaskStoreSuite(t *testing.T) {
 // TODO: Merge persistence-tests into the tests directory.
 
 func TestCassandraHistoryStoreSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -199,6 +203,7 @@ func TestCassandraHistoryStoreSuite(t *testing.T) {
 }
 
 func TestCassandraTaskQueueSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -212,6 +217,7 @@ func TestCassandraTaskQueueSuite(t *testing.T) {
 }
 
 func TestCassandraFairTaskQueueSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -225,6 +231,7 @@ func TestCassandraFairTaskQueueSuite(t *testing.T) {
 }
 
 func TestCassandraTaskQueueTaskSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -238,6 +245,7 @@ func TestCassandraTaskQueueTaskSuite(t *testing.T) {
 }
 
 func TestCassandraTaskQueueFairTaskSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -251,6 +259,7 @@ func TestCassandraTaskQueueFairTaskSuite(t *testing.T) {
 }
 
 func TestCassandraTaskQueueUserDataSuite(t *testing.T) {
+	t.Parallel()
 	testData, tearDown := setUpCassandraTest(t)
 	defer tearDown()
 
@@ -264,27 +273,31 @@ func TestCassandraTaskQueueUserDataSuite(t *testing.T) {
 }
 
 func TestCassandraHistoryV2Persistence(t *testing.T) {
+	t.Parallel()
 	s := new(persistencetests.HistoryV2PersistenceSuite)
 	s.TestBase = persistencetests.NewTestBaseWithCassandra(&persistencetests.TestBaseOptions{})
 	s.TestBase.Setup(nil)
 	suite.Run(t, s)
 }
 
 func TestCassandraMetadataPersistenceV2(t *testing.T) {
+	t.Parallel()
 	s := new(persistencetests.MetadataPersistenceSuiteV2)
 	s.TestBase = persistencetests.NewTestBaseWithCassandra(&persistencetests.TestBaseOptions{})
 	s.TestBase.Setup(nil)
 	suite.Run(t, s)
 }
 
 func TestCassandraClusterMetadataPersistence(t *testing.T) {
+	t.Parallel()
 	s := new(persistencetests.ClusterMetadataManagerSuite)
 	s.TestBase = persistencetests.NewTestBaseWithCassandra(&persistencetests.TestBaseOptions{})
 	s.TestBase.Setup(nil)
 	suite.Run(t, s)
 }
 
 func TestCassandraQueuePersistence(t *testing.T) {
+	t.Parallel()
 	s := new(persistencetests.QueuePersistenceSuite)
 	s.TestBase = persistencetests.NewTestBaseWithCassandra(&persistencetests.TestBaseOptions{})
 	s.TestBase.Setup(nil)
@@ -315,6 +328,7 @@ func TestCassandraQueueV2Persistence(t *testing.T) {
 }
 
 func TestCassandraNexusEndpointPersistence(t *testing.T) {
+	t.Parallel()
 	cluster := persistencetests.NewTestClusterForCassandra(&persistencetests.TestBaseOptions{}, log.NewNoopLogger())
 	cluster.SetupTestDatabase()
 	t.Cleanup(cluster.TearDownTestDatabase)