server: remove contention event registry from baseStatusServer

Previously, baseStatusServer holds a reference to contention.Registry.
This reference of contention.Registry is used to power the
/ListContentionEvents endpoint. However, this is not ideal for two
reasons:
1. baseStatusServer already holds a reference to *server.SQLServer,
   which in turn contains contention.Registry through its ExecutorConfig
   field. This means that there's no good reason to have another field
   in baseStatusServer to hold this additional reference.
2. The ongoing contention event registry work will make contention
   registry depend on status server to perform transaction ID resolution
   protocol. As it stand today, the status server's construction depends
   on the creation of contention.Registry. By introducing transaction ID
   resolution protocol into contention.Registry, we will be introducing
   a cyclical reference, which can lead to ugly API design.

This commit removes the baseStatusServer's reference on
contention.Registry, and instead directly fetching from executor config.

Release note: None

pkg/server/server.go

@@ -629,7 +629,6 @@ func NewServer(cfg Config, stopper *stop.Stopper) (*Server, error) {
 	sAdmin := newAdminServer(lateBoundServer, adminAuthzCheck, internalExecutor)
 	sHTTP := newHTTPServer(cfg)
 	sessionRegistry := sql.NewSessionRegistry()
-	contentionRegistry := contention.NewRegistry()
 	flowScheduler := flowinfra.NewFlowScheduler(cfg.AmbientCtx, stopper, st)
 
 	sStatus := newStatusServer(
@@ -647,10 +646,11 @@ func NewServer(cfg Config, stopper *stop.Stopper) (*Server, error) {
 		node.stores,
 		stopper,
 		sessionRegistry,
-		contentionRegistry,
 		flowScheduler,
 		internalExecutor,
 	)
+
+	contentionRegistry := contention.NewRegistry()
 	// TODO(tbg): don't pass all of Server into this to avoid this hack.
 	sAuth := newAuthenticationServer(lateBoundServer)
 	for i, gw := range []grpcGatewayServer{sAdmin, sStatus, sAuth, &sTS} {

pkg/server/status.go

@@ -135,14 +135,13 @@ type baseStatusServer struct {
 	serverpb.UnimplementedStatusServer
 
 	log.AmbientContext
-	privilegeChecker   *adminPrivilegeChecker
-	sessionRegistry    *sql.SessionRegistry
-	contentionRegistry *contention.Registry
-	flowScheduler      *flowinfra.FlowScheduler
-	st                 *cluster.Settings
-	sqlServer          *SQLServer
-	rpcCtx             *rpc.Context
-	stopper            *stop.Stopper
+	privilegeChecker *adminPrivilegeChecker
+	sessionRegistry  *sql.SessionRegistry
+	flowScheduler    *flowinfra.FlowScheduler
+	st               *cluster.Settings
+	sqlServer        *SQLServer
+	rpcCtx           *rpc.Context
+	stopper          *stop.Stopper
 }
 
 // getLocalSessions returns a list of local sessions on this node. Note that the
@@ -307,7 +306,7 @@ func (b *baseStatusServer) ListLocalContentionEvents(
 	}
 
 	return &serverpb.ListContentionEventsResponse{
-		Events: b.contentionRegistry.Serialize(),
+		Events: b.sqlServer.execCfg.ContentionRegistry.Serialize(),
 	}, nil
 }
 
@@ -415,21 +414,19 @@ func newStatusServer(
 	stores *kvserver.Stores,
 	stopper *stop.Stopper,
 	sessionRegistry *sql.SessionRegistry,
-	contentionRegistry *contention.Registry,
 	flowScheduler *flowinfra.FlowScheduler,
 	internalExecutor *sql.InternalExecutor,
 ) *statusServer {
 	ambient.AddLogTag("status", nil)
 	server := &statusServer{
 		baseStatusServer: &baseStatusServer{
-			AmbientContext:     ambient,
-			privilegeChecker:   adminAuthzCheck,
-			sessionRegistry:    sessionRegistry,
-			contentionRegistry: contentionRegistry,
-			flowScheduler:      flowScheduler,
-			st:                 st,
-			rpcCtx:             rpcCtx,
-			stopper:            stopper,
+			AmbientContext:   ambient,
+			privilegeChecker: adminAuthzCheck,
+			sessionRegistry:  sessionRegistry,
+			flowScheduler:    flowScheduler,
+			st:               st,
+			rpcCtx:           rpcCtx,
+			stopper:          stopper,
 		},
 		cfg:              cfg,
 		admin:            adminServer,

pkg/server/tenant.go

@@ -163,9 +163,10 @@ func StartTenant(
 	// the SQL server object.
 	tenantStatusServer := newTenantStatusServer(
 		baseCfg.AmbientCtx, &adminPrivilegeChecker{ie: args.circularInternalExecutor},
-		args.sessionRegistry, args.contentionRegistry, args.flowScheduler, baseCfg.Settings, nil,
+		args.sessionRegistry, args.flowScheduler, baseCfg.Settings, nil,
 		args.rpcContext, args.stopper,
 	)
+	args.contentionRegistry = contention.NewRegistry()
 	args.sqlStatusServer = tenantStatusServer
 	s, err := newSQLServer(ctx, args)
 	tenantStatusServer.sqlServer = s
@@ -493,7 +494,6 @@ func makeTenantSQLServerArgs(
 	// writing): the blob service and DistSQL.
 	dummyRPCServer := rpc.NewServer(rpcContext)
 	sessionRegistry := sql.NewSessionRegistry()
-	contentionRegistry := contention.NewRegistry()
 	flowScheduler := flowinfra.NewFlowScheduler(baseCfg.AmbientCtx, stopper, st)
 	return sqlServerArgs{
 		sqlServerOptionalKVArgs: sqlServerOptionalKVArgs{
@@ -529,7 +529,6 @@ func makeTenantSQLServerArgs(
 		registry:                 registry,
 		recorder:                 recorder,
 		sessionRegistry:          sessionRegistry,
-		contentionRegistry:       contentionRegistry,
 		flowScheduler:            flowScheduler,
 		circularInternalExecutor: circularInternalExecutor,
 		circularJobRegistry:      circularJobRegistry,

pkg/server/tenant_status.go

@@ -77,7 +77,6 @@ func newTenantStatusServer(
 	ambient log.AmbientContext,
 	privilegeChecker *adminPrivilegeChecker,
 	sessionRegistry *sql.SessionRegistry,
-	contentionRegistry *contention.Registry,
 	flowScheduler *flowinfra.FlowScheduler,
 	st *cluster.Settings,
 	sqlServer *SQLServer,
@@ -87,15 +86,14 @@ func newTenantStatusServer(
 	ambient.AddLogTag("tenant-status", nil)
 	return &tenantStatusServer{
 		baseStatusServer: baseStatusServer{
-			AmbientContext:     ambient,
-			privilegeChecker:   privilegeChecker,
-			sessionRegistry:    sessionRegistry,
-			contentionRegistry: contentionRegistry,
-			flowScheduler:      flowScheduler,
-			st:                 st,
-			sqlServer:          sqlServer,
-			rpcCtx:             rpcCtx,
-			stopper:            stopper,
+			AmbientContext:   ambient,
+			privilegeChecker: privilegeChecker,
+			sessionRegistry:  sessionRegistry,
+			flowScheduler:    flowScheduler,
+			st:               st,
+			sqlServer:        sqlServer,
+			rpcCtx:           rpcCtx,
+			stopper:          stopper,
 		},
 	}
 }