scheduler: adjust Batch size when created by ConfigJSONDecoder (#…

…4747)

close #4610

adjust `Batch` size when created by `ConfigJSONDecoder`

Signed-off-by: Cabinfever_B <cabinfeveroier@gmail.com>

server/cluster/coordinator_test.go

@@ -16,6 +16,7 @@ package cluster
 
 import (
 	"context"
+	"encoding/json"
 	"math/rand"
 	"sync"
 	"testing"
@@ -675,6 +676,18 @@ func (s *testCoordinatorSuite) TestAddScheduler(c *C) {
 	c.Assert(tc.addLeaderRegion(3, 3, 1, 2), IsNil)
 
 	oc := co.opController
+
+	// test ConfigJSONDecoder create
+	bl, err := schedule.CreateScheduler(schedulers.BalanceLeaderType, oc, storage.NewStorageWithMemoryBackend(), schedule.ConfigJSONDecoder([]byte("{}")))
+	c.Assert(err, IsNil)
+	conf, err := bl.EncodeConfig()
+	c.Assert(err, IsNil)
+	data := make(map[string]interface{})
+	err = json.Unmarshal(conf, &data)
+	c.Assert(err, IsNil)
+	batch := data["batch"].(float64)
+	c.Assert(int(batch), Equals, 4)
+
 	gls, err := schedule.CreateScheduler(schedulers.GrantLeaderType, oc, storage.NewStorageWithMemoryBackend(), schedule.ConfigSliceDecoder(schedulers.GrantLeaderType, []string{"0"}))
 	c.Assert(err, IsNil)
 	c.Assert(co.addScheduler(gls), NotNil)

server/schedulers/balance_leader.go

@@ -76,6 +76,9 @@ func init() {
 		if err := decoder(conf); err != nil {
 			return nil, err
 		}
+		if conf.Batch == 0 {
+			conf.Batch = BalanceLeaderBatchSize
+		}
 		return newBalanceLeaderScheduler(opController, conf), nil
 	})
 }