Actually disable the schedulers

command/agent/agent.go

@@ -144,8 +144,8 @@ func convertServerConfig(agentConfig *Config, logOutput io.Writer) (*nomad.Confi
 	if agentConfig.Server.RaftProtocol != 0 {
 		conf.RaftConfig.ProtocolVersion = raft.ProtocolVersion(agentConfig.Server.RaftProtocol)
 	}
-	if agentConfig.Server.NumSchedulers != 0 {
-		conf.NumSchedulers = agentConfig.Server.NumSchedulers
+	if agentConfig.Server.NumSchedulers != nil {
+		conf.NumSchedulers = *agentConfig.Server.NumSchedulers
 	}
 	if len(agentConfig.Server.EnabledSchedulers) != 0 {
 		// Convert to a set and require the core scheduler

command/agent/alloc_endpoint_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/golang/snappy"
 	"github.com/hashicorp/nomad/acl"
 	"github.com/hashicorp/nomad/client/allocdir"
+	"github.com/hashicorp/nomad/helper"
 	"github.com/hashicorp/nomad/helper/uuid"
 	"github.com/hashicorp/nomad/nomad/mock"
 	"github.com/hashicorp/nomad/nomad/structs"
@@ -437,7 +438,7 @@ func TestHTTP_AllocSnapshot_Atomic(t *testing.T) {
 	t.Parallel()
 	httpTest(t, func(c *Config) {
 		// Disable the schedulers
-		c.Server.NumSchedulers = 0
+		c.Server.NumSchedulers = helper.IntToPtr(0)
 	}, func(s *TestAgent) {
 		// Create an alloc
 		state := s.server.State()

command/agent/config.go

@@ -268,7 +268,7 @@ type ServerConfig struct {
 	// NumSchedulers is the number of scheduler thread that are run.
 	// This can be as many as one per core, or zero to disable this server
 	// from doing any scheduling work.
-	NumSchedulers int `mapstructure:"num_schedulers"`
+	NumSchedulers *int `mapstructure:"num_schedulers"`
 
 	// EnabledSchedulers controls the set of sub-schedulers that are
 	// enabled for this server to handle. This will restrict the evaluations
@@ -1009,8 +1009,8 @@ func (a *ServerConfig) Merge(b *ServerConfig) *ServerConfig {
 	if b.RaftProtocol != 0 {
 		result.RaftProtocol = b.RaftProtocol
 	}
-	if b.NumSchedulers != 0 {
-		result.NumSchedulers = b.NumSchedulers
+	if b.NumSchedulers != nil {
+		result.NumSchedulers = helper.IntToPtr(*b.NumSchedulers)
 	}
 	if b.NodeGCThreshold != "" {
 		result.NodeGCThreshold = b.NodeGCThreshold

command/agent/config_parse_test.go

@@ -88,7 +88,7 @@ func TestConfig_Parse(t *testing.T) {
 					DataDir:                "/tmp/data",
 					ProtocolVersion:        3,
 					RaftProtocol:           3,
-					NumSchedulers:          2,
+					NumSchedulers:          helper.IntToPtr(2),
 					EnabledSchedulers:      []string{"test"},
 					NodeGCThreshold:        "12h",
 					EvalGCThreshold:        "12h",

command/agent/config_test.go

@@ -105,7 +105,7 @@ func TestConfig_Merge(t *testing.T) {
 			DataDir:                "/tmp/data1",
 			ProtocolVersion:        1,
 			RaftProtocol:           1,
-			NumSchedulers:          1,
+			NumSchedulers:          helper.IntToPtr(1),
 			NodeGCThreshold:        "1h",
 			HeartbeatGrace:         30 * time.Second,
 			MinHeartbeatTTL:        30 * time.Second,
@@ -255,7 +255,7 @@ func TestConfig_Merge(t *testing.T) {
 			DataDir:                "/tmp/data2",
 			ProtocolVersion:        2,
 			RaftProtocol:           2,
-			NumSchedulers:          2,
+			NumSchedulers:          helper.IntToPtr(2),
 			EnabledSchedulers:      []string{structs.JobTypeBatch},
 			NodeGCThreshold:        "12h",
 			HeartbeatGrace:         2 * time.Minute,