Support API service of checking stats of the worker pool

src/jobservice_v2/api/handler.go

@@ -65,11 +65,12 @@ func (dh *DefaultHandler) HandleLaunchJobReq(w http.ResponseWriter, req *http.Re
 		dh.handleError(w, http.StatusInternalServerError, errs.LaunchJobError(err))
 		return
 	}
-	data, err = json.Marshal(jobStats)
-	if err != nil {
-		dh.handleError(w, http.StatusInternalServerError, errs.HandleJSONDataError(err))
+
+	data, ok := dh.handleJSONData(w, jobStats)
+	if !ok {
 		return
 	}
+
 	w.WriteHeader(http.StatusAccepted)
 	w.Write(data)
 }
@@ -89,7 +90,29 @@ func (dh *DefaultHandler) HandleJobActionReq(w http.ResponseWriter, req *http.Re
 
 //HandleCheckStatusReq is implementation of method defined in interface 'Handler'
 func (dh *DefaultHandler) HandleCheckStatusReq(w http.ResponseWriter, req *http.Request) {
+	stats, err := dh.controller.CheckStatus()
+	if err != nil {
+		dh.handleError(w, http.StatusInternalServerError, errs.CheckStatsError(err))
+		return
+	}
+
+	data, ok := dh.handleJSONData(w, stats)
+	if !ok {
+		return
+	}
+
 	w.WriteHeader(http.StatusOK)
+	w.Write(data)
+}
+
+func (dh *DefaultHandler) handleJSONData(w http.ResponseWriter, object interface{}) ([]byte, bool) {
+	data, err := json.Marshal(object)
+	if err != nil {
+		dh.handleError(w, http.StatusInternalServerError, errs.HandleJSONDataError(err))
+		return nil, false
+	}
+
+	return data, true
 }
 
 func (dh *DefaultHandler) handleError(w http.ResponseWriter, code int, err error) {

src/jobservice_v2/core/controller.go

@@ -82,7 +82,7 @@ func (c *Controller) RetryJob(jonID string) error {
 
 //CheckStatus is implementation of same method in core interface.
 func (c *Controller) CheckStatus() (models.JobPoolStats, error) {
-	return models.JobPoolStats{}, nil
+	return c.backendPool.Stats()
 }
 
 func validJobReq(req models.JobRequest) error {

src/jobservice_v2/errs/errors.go

@@ -18,6 +18,8 @@ const (
 	MissingBackendHandlerErrorCode
 	//LaunchJobErrorCode is code for the error of launching job
 	LaunchJobErrorCode
+	//CheckStatsErrorCode is code for the error of checking stats of worker pool
+	CheckStatsErrorCode
 )
 
 //baseError ...
@@ -65,6 +67,11 @@ func LaunchJobError(err error) error {
 	return New(LaunchJobErrorCode, "Launch job failed with error", err.Error())
 }
 
+//CheckStatsError is error wrapper for the error of checking stats failed
+func CheckStatsError(err error) error {
+	return New(CheckStatsErrorCode, "Check stats of server failed with error", err.Error())
+}
+
 //jobStoppedError is designed for the case of stopping job.
 type jobStoppedError struct {
 	baseError

src/jobservice_v2/models/models.go

@@ -46,4 +46,11 @@ type JobStatData struct {
 }
 
 //JobPoolStats represent the healthy and status of the job service.
-type JobPoolStats struct{}
+type JobPoolStats struct {
+	WorkerPoolID string   `json:"worker_pool_id"`
+	StartedAt    int64    `json:"started_at"`
+	HeartbeatAt  int64    `json:"heartbeat_at"`
+	JobNames     []string `json:"job_names"`
+	Concurrency  uint     `json:"concurrency"`
+	Status       string   `json:"status"`
+}

src/jobservice_v2/pool/redis_pool.go

@@ -5,6 +5,7 @@ package pool
 import (
 	"errors"
 	"fmt"
+	"os"
 	"time"
 
 	"github.com/garyburd/redigo/redis"
@@ -22,6 +23,12 @@ var (
 	healthCheckPeriod     = time.Minute
 	dialReadTimeout       = healthCheckPeriod + 10*time.Second
 	dialWriteTimeout      = 10 * time.Second
+	workerPoolDeadTime    = 10 * time.Second
+)
+
+const (
+	workerPoolStatusHealthy = "Healthy"
+	workerPoolStatusDead    = "Dead"
 )
 
 //GoCraftWorkPool is the pool implementation based on gocraft/work powered by redis.
@@ -252,7 +259,34 @@ func (gcwp *GoCraftWorkPool) PeriodicallyEnqueue(jobName string, params models.P
 
 //Stats of pool
 func (gcwp *GoCraftWorkPool) Stats() (models.JobPoolStats, error) {
-	return models.JobPoolStats{}, nil
+	//Get the status of workerpool via client
+	hbs, err := gcwp.client.WorkerPoolHeartbeats()
+	if err != nil {
+		return models.JobPoolStats{}, err
+	}
+
+	//Find the heartbeat of this pool via pid
+	pid := os.Getpid()
+	for _, hb := range hbs {
+		if hb.Pid == pid {
+			wPoolStatus := workerPoolStatusHealthy
+			if time.Unix(hb.HeartbeatAt, 0).Add(workerPoolDeadTime).Before(time.Now()) {
+				wPoolStatus = workerPoolStatusDead
+			}
+			stats := models.JobPoolStats{
+				WorkerPoolID: hb.WorkerPoolID,
+				StartedAt:    hb.StartedAt,
+				HeartbeatAt:  hb.HeartbeatAt,
+				JobNames:     hb.JobNames,
+				Concurrency:  hb.Concurrency,
+				Status:       wPoolStatus,
+			}
+
+			return stats, nil
+		}
+	}
+
+	return models.JobPoolStats{}, errors.New("Failed to get stats of worker pool")
 }
 
 //IsKnownJob ...