Rename new shardmanager service to shard-distributor (#6496)

What changed?
Renamed the new shard-manager service to shard-distributor

Why?
We want to split the shard management system in two service, shard-distributor and a load-balancer. Also there is already a shard manager struct in the code, which would be quite confusing

How did you test it?
Unit tests

Potential risks
The change is NOT backwards compatible, the service is still prototyping so noone show rely on it. We need to change the names internally when we pull in this change.

Release notes

Documentation Changes

cmd/server/cadence/server.go

@@ -54,7 +54,7 @@ import (
 	"github.com/uber/cadence/service/frontend"
 	"github.com/uber/cadence/service/history"
 	"github.com/uber/cadence/service/matching"
-	"github.com/uber/cadence/service/shardmanager"
+	"github.com/uber/cadence/service/sharddistributor"
 	"github.com/uber/cadence/service/worker"
 )
 
@@ -272,8 +272,8 @@ func (s *server) startService() common.Daemon {
 		daemon, err = matching.NewService(&params)
 	case service.Worker:
 		daemon, err = worker.NewService(&params)
-	case service.ShardManager:
-		daemon, err = shardmanager.NewService(&params, resource.NewResourceFactory())
+	case service.ShardDistributor:
+		daemon, err = sharddistributor.NewService(&params, resource.NewResourceFactory())
 	}
 	if err != nil {
 		params.Logger.Fatal("Fail to start "+s.name+" service ", tag.Error(err))

common/metrics/defs.go

@@ -67,7 +67,7 @@ const (
 	History
 	Matching
 	Worker
-	ShardManager
+	ShardDistributor
 	NumServices
 )
 

common/service/metrics.go

@@ -36,8 +36,8 @@ func GetMetricsServiceIdx(serviceName string, logger log.Logger) metrics.Service
 		return metrics.Matching
 	case Worker:
 		return metrics.Worker
-	case ShardManager:
-		return metrics.ShardManager
+	case ShardDistributor:
+		return metrics.ShardDistributor
 	default:
 		logger.Fatal("Unknown service name for metrics!")
 	}

common/service/name.go

@@ -33,15 +33,15 @@ const (
 	Matching = "cadence-matching"
 	// Worker is the name of the worker service
 	Worker = "cadence-worker"
-	// ShardManager is the name of the shard manager service
-	ShardManager = "cadence-shard-manager"
+	// ShardDistributor is the name of the shard distributor service
+	ShardDistributor = "cadence-shard-distributor"
 )
 
 // ListWithRing contains the list of all cadence services that has a hash ring
 var ListWithRing = []string{Frontend, History, Matching, Worker}
 
 // List contains the list of all cadence services
-var List = []string{Frontend, History, Matching, Worker, ShardManager}
+var List = []string{Frontend, History, Matching, Worker, ShardDistributor}
 
 // ShortName returns cadence service name without "cadence-" prefix
 func ShortName(name string) string {

common/service/name_test.go

@@ -36,6 +36,6 @@ func TestServiceNames(t *testing.T) {
 	assert.Equal(t, fullName, FullName(shortName))
 	assert.Equal(t, fullName, FullName(fullName))
 
-	assert.Equal(t, []string{"cadence-frontend", "cadence-history", "cadence-matching", "cadence-worker", "cadence-shard-manager"}, List)
-	assert.Equal(t, []string{"frontend", "history", "matching", "worker", "shard-manager"}, ShortNames(List))
+	assert.Equal(t, []string{"cadence-frontend", "cadence-history", "cadence-matching", "cadence-worker", "cadence-shard-distributor"}, List)
+	assert.Equal(t, []string{"frontend", "history", "matching", "worker", "shard-distributor"}, ShortNames(List))
 }

config/development.yaml

@@ -75,7 +75,7 @@ services:
     pprof:
       port: ${WORKER_PORT_PPROF:7940}
 
-  shard-manager:
+  shard-distributor:
     rpc:
       port: 7941
       bindOnLocalHost: true

service/shardmanager/service.go → service/sharddistributor/service.go

@@ -18,7 +18,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-package shardmanager
+package sharddistributor
 
 import (
 	"sync/atomic"
@@ -27,10 +27,10 @@ import (
 	"github.com/uber/cadence/common/dynamicconfig"
 	"github.com/uber/cadence/common/resource"
 	"github.com/uber/cadence/common/service"
-	"github.com/uber/cadence/service/shardmanager/config"
+	"github.com/uber/cadence/service/sharddistributor/config"
 )
 
-// Service represents the shard manager service
+// Service represents the shard distributor service
 type Service struct {
 	resource.Resource
 
@@ -57,13 +57,13 @@ func NewService(
 
 	serviceResource, err := factory.NewResource(
 		params,
-		service.ShardManager,
+		service.ShardDistributor,
 		&service.Config{
 			PersistenceMaxQPS:        serviceConfig.PersistenceMaxQPS,
 			PersistenceGlobalMaxQPS:  serviceConfig.PersistenceGlobalMaxQPS,
 			ThrottledLoggerMaxRPS:    serviceConfig.ThrottledLogRPS,
 			IsErrorRetryableFunction: common.IsServiceTransientError,
-			// shard manager doesn't need visibility config as it never read or write visibility
+			// shard distributor doesn't need visibility config as it never read or write visibility
 		},
 	)
 	if err != nil {
@@ -85,7 +85,7 @@ func (s *Service) Start() {
 	}
 
 	logger := s.GetLogger()
-	logger.Info("shard manager starting")
+	logger.Info("shard distributor starting")
 
 	// setup the handler
 
@@ -103,5 +103,5 @@ func (s *Service) Stop() {
 
 	s.Resource.Stop()
 
-	s.GetLogger().Info("shard manager stopped")
+	s.GetLogger().Info("shard distributor stopped")
 }

service/shardmanager/service_test.go → service/sharddistributor/service_test.go

@@ -20,7 +20,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-package shardmanager
+package sharddistributor
 
 import (
 	"sync/atomic"