add jitter for the task

jitter is the max number of seconds a task can wait for before actual
running.

pkg/perf/cpubench/cpubench_task.go

@@ -4,7 +4,9 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"math/rand"
 	"os/exec"
+	"time"
 
 	"github.com/threefoldtech/zos/pkg/perf"
 	"github.com/threefoldtech/zos/pkg/stubs"
@@ -24,6 +26,8 @@ type CPUBenchmarkTask struct {
 	schedule string
 	// description briefly describe what a task do.
 	description string
+	// jitter is max number of seconds the job can sleep before actual execution.
+	jitter uint32
 }
 
 // CPUBenchmarkResult holds CPU benchmark results with the workloads number during the benchmark.
@@ -42,6 +46,7 @@ func NewCPUBenchmarkTask() CPUBenchmarkTask {
 		taskID:      cpuBenchmarkTaskID,
 		schedule:    cpuBenchmarkCronSchedule,
 		description: cpuBenchmarkDescription,
+		jitter:      10 * 60,
 	}
 }
 
@@ -60,8 +65,15 @@ func (c *CPUBenchmarkTask) Description() string {
 	return c.description
 }
 
+// Jitter returns the duration the task will sleep for before running.
+func (c *CPUBenchmarkTask) Jitter() time.Duration {
+	jitter := time.Duration(rand.Int31n(int32(c.jitter))) * time.Second
+	return jitter
+}
+
 // Run executes the CPU benchmark.
 func (c *CPUBenchmarkTask) Run(ctx context.Context) (interface{}, error) {
+	time.Sleep(c.Jitter())
 	cpubenchOut, err := exec.CommandContext(ctx, "cpubench", "-j").CombinedOutput()
 	if err != nil {
 		return nil, fmt.Errorf("failed to execute cpubench command: %w", err)

pkg/perf/iperf/iperf_task.go

@@ -4,10 +4,12 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"math/rand"
 	"net"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"time"
 
 	"github.com/pkg/errors"
 	"github.com/rs/zerolog/log"
@@ -22,6 +24,7 @@ type IperfTest struct {
 	taskID      string
 	schedule    string
 	description string
+	jitter      uint32
 }
 
 // IperfResult for iperf test results
@@ -47,6 +50,7 @@ func NewTask() perf.Task {
 		taskID:      "iperf",
 		schedule:    "0 0 */6 * * *",
 		description: "Test public nodes network performance with both UDP and TCP over IPv4 and IPv6",
+		jitter:      10 * 60,
 	}
 }
 
@@ -65,8 +69,15 @@ func (t *IperfTest) Description() string {
 	return t.description
 }
 
+// Jitter returns the duration the task will sleep for before running.
+func (t *IperfTest) Jitter() time.Duration {
+	jitter := time.Duration(rand.Int31n(int32(t.jitter))) * time.Second
+	return jitter
+}
+
 // Run runs the tcp test and returns the result
 func (t *IperfTest) Run(ctx context.Context) (interface{}, error) {
+	time.Sleep(t.Jitter())
 	env := environment.MustGet()
 	g := graphql.NewGraphQl(env.GraphQL)
 

pkg/perf/publicip/publicip_task.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"math/rand"
 	"net"
 	"net/http"
 	"os/exec"
@@ -45,9 +46,11 @@ const testMacvlan = "pub"
 const testNamespace = "pubtestns"
 
 type publicIPValidationTask struct {
-	taskID      string
-	schedule    string
-	description string
+	taskID        string
+	schedule      string
+	description   string
+	jitter        uint32
+	farmIPsReport map[string]IPReport
 }
 
 type IPReport struct {
@@ -59,9 +62,11 @@ var _ perf.Task = (*publicIPValidationTask)(nil)
 
 func NewTask() perf.Task {
 	return &publicIPValidationTask{
-		taskID:      taskID,
-		schedule:    taskSchedule,
-		description: taskDescription,
+		taskID:        taskID,
+		schedule:      taskSchedule,
+		description:   taskDescription,
+		jitter:        10 * 60,
+		farmIPsReport: make(map[string]IPReport),
 	}
 }
 
@@ -77,7 +82,13 @@ func (p *publicIPValidationTask) Description() string {
 	return p.description
 }
 
+func (p *publicIPValidationTask) Jitter() time.Duration {
+	jitter := time.Duration(rand.Int31n(int32(p.jitter))) * time.Second
+	return jitter
+}
+
 func (p *publicIPValidationTask) Run(ctx context.Context) (interface{}, error) {
+	time.Sleep(p.Jitter())
 
 	netNS, err := namespace.GetByName(testNamespace)
 	if err != nil {

pkg/perf/tasks.go

@@ -2,11 +2,13 @@ package perf
 
 import (
 	"context"
+	"time"
 )
 
 type Task interface {
 	ID() string
 	Cron() string
 	Description() string
+	Jitter() time.Duration
 	Run(ctx context.Context) (interface{}, error)
 }