ddl, parser, executor, ddl worker: admin pause and resume ddl jobs

DEPS.bzl

@@ -786,8 +786,8 @@ def go_deps():
         name = "com_github_cznic_strutil",
         build_file_proto_mode = "disable_global",
         importpath = "github.com/cznic/strutil",
-        sum = "h1:0rkFMAbn5KBKNpJyHQ6Prb95vIKanmAe62KxsrN+sqA=",
-        version = "v0.0.0-20171016134553-529a34b1c186",
+        sum = "h1:MZRmHqDBd0vxNwenEbKSQqRVT24d3C05ft8kduSwlqM=",
+        version = "v0.0.0-20181122101858-275e90344537",
     )
     go_repository(
         name = "com_github_daixiang0_gci",
@@ -6076,8 +6076,8 @@ def go_deps():
         name = "org_modernc_golex",
         build_file_proto_mode = "disable_global",
         importpath = "modernc.org/golex",
-        sum = "h1:EYKY1a3wStt0RzHaH8mdSRNg78Ub0OHxYfCRWw35YtM=",
-        version = "v1.0.1",
+        sum = "h1:IaPGsXg0FX9vkth++hQ/YIHjj0v4eZGJwoMrejWR1Ts=",
+        version = "v1.0.4",
     )
     go_repository(
         name = "org_modernc_lex",
@@ -6097,8 +6097,8 @@ def go_deps():
         name = "org_modernc_mathutil",
         build_file_proto_mode = "disable_global",
         importpath = "modernc.org/mathutil",
-        sum = "h1:ij3fYGe8zBF4Vu+g0oT7mB06r8sqGWKuJu1yXeR4by8=",
-        version = "v1.4.1",
+        sum = "h1:rV0Ko/6SfM+8G+yKiyI830l3Wuz1zRutdslNoQ0kfiQ=",
+        version = "v1.5.0",
     )
     go_repository(
         name = "org_modernc_parser",
@@ -6118,15 +6118,15 @@ def go_deps():
         name = "org_modernc_sortutil",
         build_file_proto_mode = "disable_global",
         importpath = "modernc.org/sortutil",
-        sum = "h1:SUTM1sCR0Ldpv7dbB/KCPC2zHHsZ1KrSkhmGmmV22CQ=",
-        version = "v1.0.0",
+        sum = "h1:VQGxbQGcHaQeB/BX9TQjrHFmOA0bounO1X/jvOfRo6Q=",
+        version = "v1.1.1",
     )
     go_repository(
         name = "org_modernc_strutil",
         build_file_proto_mode = "disable_global",
         importpath = "modernc.org/strutil",
-        sum = "h1:+1/yCzZxY2pZwwrsbH+4T7BQMoLQ9QiBshRC9eicYsc=",
-        version = "v1.1.0",
+        sum = "h1:fNMm+oJklMGYfU9Ylcywl0CO5O6nTfaowNsh2wpPjzY=",
+        version = "v1.1.3",
     )
     go_repository(
         name = "org_modernc_y",

ddl/BUILD.bazel

@@ -197,6 +197,7 @@ go_test(
         "mv_index_test.go",
         "options_test.go",
         "partition_test.go",
+        "pause_test.go",
         "placement_policy_ddl_test.go",
         "placement_policy_test.go",
         "placement_sql_test.go",

ddl/backfilling.go

@@ -285,8 +285,8 @@ func (w *backfillWorker) handleBackfillTask(d *ddlCtx, task *reorgBackfillTask,
 	rc := d.getReorgCtx(jobID)
 
 	for {
-		// Give job chance to be canceled, if we not check it here,
-		// if there is panic in bf.BackfillData we will never cancel the job.
+		// Give job chance to be canceled or paused, if we not check it here,
+		// we will never cancel the job once there is panic in bf.BackfillData.
 		// Because reorgRecordTask may run a long time,
 		// we should check whether this ddl job is still runnable.
 		err := d.isReorgRunnable(jobID, false)
@@ -721,7 +721,6 @@ func (dc *ddlCtx) writePhysicalTableRecord(sessPool *sess.Pool, t table.Physical
 		if len(kvRanges) == 0 {
 			break
 		}
-
 		logutil.BgLogger().Info("[ddl] start backfill workers to reorg record",
 			zap.Stringer("type", bfWorkerType),
 			zap.Int("workerCnt", scheduler.currentWorkerSize()),

ddl/column.go

@@ -847,6 +847,10 @@ func doReorgWorkForModifyColumn(w *worker, d *ddlCtx, t *meta.Meta, job *model.J
 		return w.updateCurrentElement(tbl, reorgInfo)
 	})
 	if err != nil {
+		if dbterror.ErrPausedDDLJob.Equal(err) {
+			return false, ver, nil
+		}
+
 		if dbterror.ErrWaitReorgTimeout.Equal(err) {
 			// If timeout, we should return, check for the owner and re-wait job done.
 			return false, ver, nil
@@ -1100,7 +1104,7 @@ func (w *worker) updateCurrentElement(t table.Table, reorgInfo *reorgInfo) error
 			TestReorgGoroutineRunning <- a
 			for {
 				time.Sleep(30 * time.Millisecond)
-				if w.getReorgCtx(reorgInfo.Job.ID).isReorgCanceled() {
+				if w.isReorgCancelled(reorgInfo.Job.ID) {
 					// Job is cancelled. So it can't be done.
 					failpoint.Return(dbterror.ErrCancelledDDLJob)
 				}

ddl/db_test.go

@@ -1106,8 +1106,10 @@ func TestCancelJobWriteConflict(t *testing.T) {
 			stmt := fmt.Sprintf("admin cancel ddl jobs %d", job.ID)
 			require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/kv/mockCommitErrorInNewTxn", `return("no_retry")`))
 			defer func() { require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/kv/mockCommitErrorInNewTxn")) }()
-			require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/ddl/mockCancelConcurencyDDL", `return(true)`))
-			defer func() { require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/ddl/mockCancelConcurencyDDL")) }()
+			require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/ddl/mockFailedCommandOnConcurencyDDL", `return(true)`))
+			defer func() {
+				require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/ddl/mockFailedCommandOnConcurencyDDL"))
+			}()
 			rs, cancelErr = tk2.Session().Execute(context.Background(), stmt)
 		}
 	}
@@ -1131,6 +1133,72 @@ func TestCancelJobWriteConflict(t *testing.T) {
 	result.Check(testkit.Rows(fmt.Sprintf("%d successful", jobID)))
 }
 
+func TestPauseJobWriteConflict(t *testing.T) {
+	store, dom := testkit.CreateMockStoreAndDomainWithSchemaLease(t, dbTestLease)
+
+	tk1 := testkit.NewTestKit(t, store)
+	tk2 := testkit.NewTestKit(t, store)
+
+	tk1.MustExec("use test")
+
+	tk1.MustExec("create table t(id int)")
+
+	var jobID int64
+	var pauseErr error
+	var pauseRS []sqlexec.RecordSet
+	hook := &callback.TestDDLCallback{Do: dom}
+	d := dom.DDL()
+	originalHook := d.GetHook()
+	d.SetHook(hook)
+	defer d.SetHook(originalHook)
+
+	// Test when pause cannot be retried and adding index succeeds.
+	hook.OnJobRunBeforeExported = func(job *model.Job) {
+		if job.Type == model.ActionAddIndex && job.State == model.JobStateRunning && job.SchemaState == model.StateWriteReorganization {
+			require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/kv/mockCommitErrorInNewTxn", `return("no_retry")`))
+			defer func() { require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/kv/mockCommitErrorInNewTxn")) }()
+			require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/ddl/mockFailedCommandOnConcurencyDDL", `return(true)`))
+			defer func() {
+				require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/ddl/mockFailedCommandOnConcurencyDDL"))
+			}()
+
+			jobID = job.ID
+			stmt := fmt.Sprintf("admin pause ddl jobs %d", jobID)
+			pauseRS, pauseErr = tk2.Session().Execute(context.Background(), stmt)
+		}
+	}
+	tk1.MustExec("alter table t add index (id)")
+	require.EqualError(t, pauseErr, "mock commit error")
+
+	var cancelRS []sqlexec.RecordSet
+	var cancelErr error
+	hook.OnJobRunBeforeExported = func(job *model.Job) {
+		if job.Type == model.ActionAddIndex && job.State == model.JobStateRunning && job.SchemaState == model.StateWriteReorganization {
+			require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/kv/mockCommitErrorInNewTxn", `return("no_retry")`))
+			defer func() { require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/kv/mockCommitErrorInNewTxn")) }()
+			require.NoError(t, failpoint.Enable("github.com/pingcap/tidb/ddl/mockFailedCommandOnConcurencyDDL", `return(false)`))
+			defer func() {
+				require.NoError(t, failpoint.Disable("github.com/pingcap/tidb/ddl/mockFailedCommandOnConcurencyDDL"))
+			}()
+
+			jobID = job.ID
+			stmt := fmt.Sprintf("admin pause ddl jobs %d", jobID)
+			pauseRS, pauseErr = tk2.Session().Execute(context.Background(), stmt)
+
+			time.Sleep(5 * time.Second)
+			stmt = fmt.Sprintf("admin cancel ddl jobs %d", jobID)
+			cancelRS, cancelErr = tk2.Session().Execute(context.Background(), stmt)
+		}
+	}
+	tk1.MustGetErrCode("alter table t add index (id)", errno.ErrCancelledDDLJob)
+	require.NoError(t, pauseErr)
+	require.NoError(t, cancelErr)
+	result := tk2.ResultSetToResultWithCtx(context.Background(), pauseRS[0], "pause ddl job successfully")
+	result.Check(testkit.Rows(fmt.Sprintf("%d successful", jobID)))
+	result = tk2.ResultSetToResultWithCtx(context.Background(), cancelRS[0], "cancel ddl job successfully")
+	result.Check(testkit.Rows(fmt.Sprintf("%d successful", jobID)))
+}
+
 func TestTxnSavepointWithDDL(t *testing.T) {
 	store, _ := testkit.CreateMockStoreAndDomainWithSchemaLease(t, dbTestLease)
 	tk := testkit.NewTestKit(t, store)