feat(batch-predictor): remove CPU limits from SparkApplication resour…

…ce (#615)

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# Description

Similar to kserve models, this PR removes CPU limits for batch
prediction jobs. If limits are set, executors will experience
significant throttling because batch jobs tend to consume all available
CPU by its nature.

# Modifications
* SparkApplication resource no longer has `coreLimit` set in driver and
executor specs. This field is optional according to [the
specs](https://github.com/kubeflow/spark-operator/blob/master/docs/api-docs.md#sparkoperator.k8s.io/v1beta2.SparkPodSpec)
and it should be safe to simply remove it.

# Tests
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- [ ] Deploying PyFunc models
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# Checklist
- [x] Added PR label
- [x] Added unit test, integration, and/or e2e tests
- [x] Tested locally
- [ ] Updated documentation
- [ ] Update Swagger spec if the PR introduce API changes
- [ ] Regenerated Golang and Python client if the PR introduces API
changes

# Release Notes
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```release-note
Remove CPU Limits for batch prediction jobs
```

api/batch/resource.go

@@ -143,7 +143,7 @@ func (t *BatchJobTemplater) createDriverSpec(job *models.PredictionJob) (v1beta2
 	}
 
 	core := getCoreRequest(userCPURequest)
-	cpuRequest, cpuLimit := getCPURequestAndLimit(userCPURequest)
+	cpuRequest := getCPURequest(userCPURequest)
 
 	memoryRequest, err := toMegabyte(job.Config.ResourceRequest.DriverMemoryRequest)
 	if err != nil {
@@ -158,9 +158,8 @@ func (t *BatchJobTemplater) createDriverSpec(job *models.PredictionJob) (v1beta2
 	return v1beta2.DriverSpec{
 		CoreRequest: cpuRequest,
 		SparkPodSpec: v1beta2.SparkPodSpec{
-			Cores:     core,
-			CoreLimit: cpuLimit,
-			Memory:    memoryRequest,
+			Cores:  core,
+			Memory: memoryRequest,
 			ConfigMaps: []v1beta2.NamePath{
 				{
 					Name: job.Name,
@@ -188,7 +187,7 @@ func (t *BatchJobTemplater) createExecutorSpec(job *models.PredictionJob) (v1bet
 	}
 
 	core := getCoreRequest(userCPURequest)
-	cpuRequest, cpuLimit := getCPURequestAndLimit(userCPURequest)
+	cpuRequest := getCPURequest(userCPURequest)
 
 	memoryRequest, err := toMegabyte(job.Config.ResourceRequest.ExecutorMemoryRequest)
 	if err != nil {
@@ -204,9 +203,8 @@ func (t *BatchJobTemplater) createExecutorSpec(job *models.PredictionJob) (v1bet
 		Instances:   &job.Config.ResourceRequest.ExecutorReplica,
 		CoreRequest: cpuRequest,
 		SparkPodSpec: v1beta2.SparkPodSpec{
-			Cores:     core,
-			CoreLimit: cpuLimit,
-			Memory:    memoryRequest,
+			Cores:  core,
+			Memory: memoryRequest,
 			ConfigMaps: []v1beta2.NamePath{
 				{
 					Name: job.Name,
@@ -251,14 +249,9 @@ func createLabel(job *models.PredictionJob) map[string]string {
 	return labels
 }
 
-func getCPURequestAndLimit(cpuRequest resource.Quantity) (*string, *string) {
+func getCPURequest(cpuRequest resource.Quantity) *string {
 	cpuRequestStr := cpuRequest.String()
-
-	cpuLimitMilli := cpuRequestToCPULimit * float64(cpuRequest.MilliValue())
-	cpuLimit := resource.NewMilliQuantity(int64(cpuLimitMilli), resource.BinarySI)
-	cpuLimitStr := cpuLimit.String()
-
-	return &cpuRequestStr, &cpuLimitStr
+	return &cpuRequestStr
 }
 
 func getCoreRequest(cpuRequest resource.Quantity) *int32 {

api/batch/resource_test.go

@@ -79,27 +79,21 @@ var (
 	}
 
 	driverCore       int32 = 1
-	driverCPURequest       = "1"     // coreToCpuRequestRatio * driverCore
-	driverCoreLimit        = "1250m" // cpuRequestToCPULimit * driverCPURequest
+	driverCPURequest       = "1" // coreToCpuRequestRatio * driverCore
 	driverMemory           = "1Gi"
 	driverMemoryInMB       = "1024m"
 
 	executorReplica    int32 = 5
 	executorCore       int32 = 1
-	executorCPURequest       = "2"     // coreToCpuRequestRatio * executorCore
-	executorCoreLimit        = "2500m" // cpuRequestToCPULimit * executorCPURequest
+	executorCPURequest       = "2" // coreToCpuRequestRatio * executorCore
 	executorMemory           = "2Gi"
 	executorMemoryInMB       = "2048m"
 
 	fractExecutorCPURequest = "1500m"
-	fractExecutorCPULimit   = "1875m"
-
-	fractDriverCPURequest = "500m"
-	fractDriverCPULimit   = "625m"
+	fractDriverCPURequest   = "500m"
 
 	largeExecutorCore       int32 = 5
 	largeExecutorCPURequest       = "8"
-	largeExecutorCPULimit         = "10"
 
 	defaultConfigMap = []v1beta2.NamePath{
 		{
@@ -193,7 +187,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &driverCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &driverCore,
-							CoreLimit:  &driverCoreLimit,
 							Memory:     &driverMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -209,7 +202,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &executorCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &executorCore,
-							CoreLimit:  &executorCoreLimit,
 							Memory:     &executorMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -272,7 +264,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &fractDriverCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &driverCore,
-							CoreLimit:  &fractDriverCPULimit,
 							Memory:     &driverMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -288,7 +279,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &executorCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &executorCore,
-							CoreLimit:  &executorCoreLimit,
 							Memory:     &executorMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -351,7 +341,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &driverCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &driverCore,
-							CoreLimit:  &driverCoreLimit,
 							Memory:     &driverMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -367,7 +356,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &fractExecutorCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &executorCore,
-							CoreLimit:  &fractExecutorCPULimit,
 							Memory:     &executorMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -430,7 +418,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &driverCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &driverCore,
-							CoreLimit:  &driverCoreLimit,
 							Memory:     &driverMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -446,7 +433,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &largeExecutorCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &largeExecutorCore,
-							CoreLimit:  &largeExecutorCPULimit,
 							Memory:     &executorMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -515,7 +501,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &driverCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &driverCore,
-							CoreLimit:  &driverCoreLimit,
 							Memory:     &driverMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,
@@ -534,7 +519,6 @@ func TestCreateSparkApplicationResource(t *testing.T) {
 						CoreRequest: &executorCPURequest,
 						SparkPodSpec: v1beta2.SparkPodSpec{
 							Cores:      &executorCore,
-							CoreLimit:  &executorCoreLimit,
 							Memory:     &executorMemoryInMB,
 							ConfigMaps: defaultConfigMap,
 							Secrets:    defaultSecret,