diff --git a/ttl/ttlworker/BUILD.bazel b/ttl/ttlworker/BUILD.bazel
index 42a654e3b3343..8d031e22e6e4a 100644
--- a/ttl/ttlworker/BUILD.bazel
+++ b/ttl/ttlworker/BUILD.bazel
@@ -25,6 +25,7 @@ go_library(
         "//types",
         "//util",
         "//util/chunk",
+        "//util/hack",
         "//util/logutil",
         "//util/sqlexec",
         "//util/timeutil",
diff --git a/ttl/ttlworker/job.go b/ttl/ttlworker/job.go
index 5551984cceb08..92b659b788e18 100644
--- a/ttl/ttlworker/job.go
+++ b/ttl/ttlworker/job.go
@@ -16,6 +16,7 @@ package ttlworker
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"sync"
 	"time"
@@ -23,6 +24,7 @@ import (
 	"github.com/pingcap/errors"
 	"github.com/pingcap/tidb/ttl/cache"
 	"github.com/pingcap/tidb/ttl/session"
+	"github.com/pingcap/tidb/util/hack"
 	"github.com/pingcap/tidb/util/logutil"
 	"go.uber.org/zap"
 )
@@ -83,11 +85,11 @@ func (job *ttlJob) changeStatus(ctx context.Context, se session.Session, status
 }
 
 func (job *ttlJob) updateState(ctx context.Context, se session.Session) error {
-	jsonStatistics, err := job.statistics.MarshalJSON()
+	summary, err := job.summary()
 	if err != nil {
-		return err
+		logutil.Logger(job.ctx).Warn("fail to generate summary for ttl job", zap.Error(err))
 	}
-	_, err = se.ExecuteSQL(ctx, updateJobState(job.tbl.ID, job.id, string(jsonStatistics), job.ownerID))
+	_, err = se.ExecuteSQL(ctx, updateJobState(job.tbl.ID, job.id, summary, job.ownerID))
 	if err != nil {
 		return errors.Trace(err)
 	}
@@ -107,13 +109,13 @@ func (job *ttlJob) nextScanTask() {
 
 // finish turns current job into last job, and update the error message and statistics summary
 func (job *ttlJob) finish(se session.Session, now time.Time) {
-	summary := job.statistics.String()
-	if job.scanTaskErr != nil {
-		summary = fmt.Sprintf("Scan Error: %s, Statistics: %s", job.scanTaskErr.Error(), summary)
+	summary, err := job.summary()
+	if err != nil {
+		logutil.Logger(job.ctx).Warn("fail to generate summary for ttl job", zap.Error(err))
 	}
 	// at this time, the job.ctx may have been canceled (to cancel this job)
 	// even when it's canceled, we'll need to update the states, so use another context
-	_, err := se.ExecuteSQL(context.TODO(), finishJobSQL(job.tbl.ID, now, summary, job.id))
+	_, err = se.ExecuteSQL(context.TODO(), finishJobSQL(job.tbl.ID, now, summary, job.id))
 	if err != nil {
 		logutil.Logger(job.ctx).Error("fail to finish a ttl job", zap.Error(err), zap.Int64("tableID", job.tbl.ID), zap.String("jobID", job.id))
 	}
@@ -168,3 +170,38 @@ func findJobWithTableID(jobs []*ttlJob, id int64) *ttlJob {
 
 	return nil
 }
+
+type ttlSummary struct {
+	TotalRows   uint64 `json:"total_rows"`
+	SuccessRows uint64 `json:"success_rows"`
+	ErrorRows   uint64 `json:"error_rows"`
+
+	TotalScanTask     int `json:"total_scan_task"`
+	ScheduledScanTask int `json:"scheduled_scan_task"`
+	FinishedScanTask  int `json:"finished_scan_task"`
+
+	ScanTaskErr string `json:"scan_task_err,omitempty"`
+}
+
+func (job *ttlJob) summary() (string, error) {
+	summary := &ttlSummary{
+		TotalRows:   job.statistics.TotalRows.Load(),
+		SuccessRows: job.statistics.SuccessRows.Load(),
+		ErrorRows:   job.statistics.ErrorRows.Load(),
+
+		TotalScanTask:     len(job.tasks),
+		ScheduledScanTask: job.taskIter,
+		FinishedScanTask:  job.finishedScanTaskCounter,
+	}
+
+	if job.scanTaskErr != nil {
+		summary.ScanTaskErr = job.scanTaskErr.Error()
+	}
+
+	summaryJSON, err := json.Marshal(summary)
+	if err != nil {
+		return "", err
+	}
+
+	return string(hack.String(summaryJSON)), nil
+}
diff --git a/ttl/ttlworker/job_manager.go b/ttl/ttlworker/job_manager.go
index 89775b35f00aa..0a5a1b7a844d8 100644
--- a/ttl/ttlworker/job_manager.go
+++ b/ttl/ttlworker/job_manager.go
@@ -595,6 +595,11 @@ func (m *JobManager) updateHeartBeat(ctx context.Context, se session.Session) er
 		if err != nil {
 			return errors.Trace(err)
 		}
+		// also updates some internal state for this job
+		err = job.updateState(ctx, se)
+		if err != nil {
+			logutil.Logger(m.ctx).Warn("fail to update state of the job", zap.String("jobID", job.id))
+		}
 	}
 	return nil
 }
diff --git a/ttl/ttlworker/job_test.go b/ttl/ttlworker/job_test.go
index 5af5d0316eed2..48d1859a0d2b4 100644
--- a/ttl/ttlworker/job_test.go
+++ b/ttl/ttlworker/job_test.go
@@ -17,6 +17,7 @@ package ttlworker
 import (
 	"testing"
 
+	"github.com/pingcap/errors"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -35,3 +36,33 @@ func TestIterScanTask(t *testing.T) {
 	job.nextScanTask()
 	assert.True(t, job.AllSpawned())
 }
+
+func TestJobSummary(t *testing.T) {
+	statistics := &ttlStatistics{}
+	statistics.TotalRows.Store(1)
+	statistics.ErrorRows.Store(255)
+	statistics.SuccessRows.Store(128)
+
+	job := &ttlJob{
+		statistics: statistics,
+		tasks:      []*ttlScanTask{{}},
+	}
+	summary, err := job.summary()
+	assert.NoError(t, err)
+	assert.Equal(t, `{"total_rows":1,"success_rows":128,"error_rows":255,"total_scan_task":1,"scheduled_scan_task":0,"finished_scan_task":0}`, summary)
+
+	job.taskIter += 1
+	summary, err = job.summary()
+	assert.NoError(t, err)
+	assert.Equal(t, `{"total_rows":1,"success_rows":128,"error_rows":255,"total_scan_task":1,"scheduled_scan_task":1,"finished_scan_task":0}`, summary)
+
+	job.finishedScanTaskCounter += 1
+	summary, err = job.summary()
+	assert.NoError(t, err)
+	assert.Equal(t, `{"total_rows":1,"success_rows":128,"error_rows":255,"total_scan_task":1,"scheduled_scan_task":1,"finished_scan_task":1}`, summary)
+
+	job.scanTaskErr = errors.New("test error")
+	summary, err = job.summary()
+	assert.NoError(t, err)
+	assert.Equal(t, `{"total_rows":1,"success_rows":128,"error_rows":255,"total_scan_task":1,"scheduled_scan_task":1,"finished_scan_task":1,"scan_task_err":"test error"}`, summary)
+}
diff --git a/ttl/ttlworker/scan.go b/ttl/ttlworker/scan.go
index 242c51fb8b686..38a4fd544535d 100644
--- a/ttl/ttlworker/scan.go
+++ b/ttl/ttlworker/scan.go
@@ -16,7 +16,6 @@ package ttlworker
 
 import (
 	"context"
-	"encoding/json"
 	"fmt"
 	"strconv"
 	"sync/atomic"
@@ -72,20 +71,6 @@ func (s *ttlStatistics) String() string {
 	return fmt.Sprintf("Total Rows: %d, Success Rows: %d, Error Rows: %d", s.TotalRows.Load(), s.SuccessRows.Load(), s.ErrorRows.Load())
 }
 
-func (s *ttlStatistics) MarshalJSON() ([]byte, error) {
-	type jsonStatistics struct {
-		TotalRows   uint64 `json:"total_rows"`
-		SuccessRows uint64 `json:"success_rows"`
-		ErrorRows   uint64 `json:"error_rows"`
-	}
-
-	return json.Marshal(jsonStatistics{
-		TotalRows:   s.TotalRows.Load(),
-		SuccessRows: s.SuccessRows.Load(),
-		ErrorRows:   s.ErrorRows.Load(),
-	})
-}
-
 type ttlScanTask struct {
 	ctx context.Context
 
diff --git a/ttl/ttlworker/scan_test.go b/ttl/ttlworker/scan_test.go
index 34a25a2539612..66582084b18f3 100644
--- a/ttl/ttlworker/scan_test.go
+++ b/ttl/ttlworker/scan_test.go
@@ -403,13 +403,3 @@ func TestScanTaskDoScan(t *testing.T) {
 	task.schemaChangeInRetry = 2
 	task.runDoScanForTest(1, "table 'test.t1' meta changed, should abort current job: [schema:1146]Table 'test.t1' doesn't exist")
 }
-
-func TestTTLStatisticsMarshalJSON(t *testing.T) {
-	statistics := &ttlStatistics{}
-	statistics.TotalRows.Store(1)
-	statistics.ErrorRows.Store(255)
-	statistics.SuccessRows.Store(128)
-	j, err := statistics.MarshalJSON()
-	require.NoError(t, err)
-	require.Equal(t, `{"total_rows":1,"success_rows":128,"error_rows":255}`, string(j))
-}