feat(apiserver): populate hosts num_run from the job store

num_run was declared in the host model but never set anywhere — the
controller's worker push carries no running-job count, so hosts always
showed 0 regardless of running jobs. Compute it live in the hosts list
handler by counting RUN jobs per exec host from store.Jobs — the same
source the jobs list uses, so the two stay consistent.

Verified: t1 with 5 RUN jobs shows num_run 5, matching the jobs list.

Co-Authored-By: Claude <noreply@anthropic.com>

src/frontend/apiserver/controllers/hosts.go

@@ -8,6 +8,7 @@ import (
 	"apiserver/store"
 	"apiserver/utils"
 	logger "apiserver/utils"
+	"encoding/json"
 	"errors"
 	"reflect"
 	"strings"
@@ -188,6 +189,21 @@ func (h *HostHandler) GetHostsInfo(ctx *gin.Context) {
 		ReturnError(ctx, common.ERROR_CODE, common.ERROR_QUERY_HOSTINFO_MSG+": "+err.Error(), nil)
 		return
 	}
+
+	// num_run is not populated by the controller's worker push, so compute it
+	// here from the apiserver's own job store — the same source the jobs list
+	// uses — keeping the hosts list consistent with the jobs list.
+	runningPerHost := countRunningJobsPerHost()
+	for i := range hqueryReply {
+		host, ok := hqueryReply[i].Data["host_name"].(string)
+		if !ok {
+			continue
+		}
+		if n, ok2 := runningPerHost[host]; ok2 {
+			hqueryReply[i].Data["num_run"] = n
+		}
+	}
+
 	logger.Debug("the host info query reply:", zap.Any("hqueryReply", hqueryReply), zap.String("pagetoken", pagetoken))
 	//convert to readable string.
 	queryResult := processHostData(hqueryReply, pagetoken)
@@ -195,6 +211,31 @@ func (h *HostHandler) GetHostsInfo(ctx *gin.Context) {
 	ReturnSuccess(ctx, common.SUCCESS_CODE, common.SUCCESS_MSG, queryResult)
 }
 
+// countRunningJobsPerHost returns the number of RUN jobs per exec host,
+// derived live from the in-memory job store (store.Jobs). RUN is the bitmask
+// JOBSTAT["RUN"] (0x02); exec hosts are read from each job's exec_hosts JSONB.
+func countRunningJobsPerHost() map[string]int {
+	counts := make(map[string]int)
+	store.Jobs.Range(func(_ uint64, job models.JobInfo) bool {
+		if job.JobStatus&models.JOBSTAT["RUN"] == 0 {
+			return true
+		}
+		var eh struct {
+			HostSlots []struct {
+				HostName string `json:"host_name"`
+			} `json:"host_slots"`
+		}
+		if err := json.Unmarshal([]byte(job.ExecHosts.String), &eh); err != nil {
+			return true
+		}
+		for _, hs := range eh.HostSlots {
+			counts[hs.HostName]++
+		}
+		return true
+	})
+	return counts
+}
+
 func selectFields(host interface{}, fields []string) map[string]interface{} {
 	result := make(map[string]interface{})
 	v := reflect.ValueOf(host)

src/frontend/apiserver/controllers/hosts_numrun_test.go

@@ -0,0 +1,61 @@
+package controllers
+
+import (
+	"testing"
+
+	"apiserver/models"
+	"apiserver/store"
+)
+
+func TestCountRunningJobsPerHost(t *testing.T) {
+	store.InitStores()
+
+	// RUN job on t1.
+	store.Jobs.Put(1, models.JobInfo{
+		JobStatus: models.JOBSTAT["RUN"],
+		ExecHosts: models.Jsonb{String: `{"host_slots":[{"host_name":"t1","num_slots":1}],"num_hosts":1}`},
+	})
+	// RUN|USUSP job on t2 — the RUN bit must still count it.
+	store.Jobs.Put(2, models.JobInfo{
+		JobStatus: models.JOBSTAT["RUN"] | models.JOBSTAT["USUSP"],
+		ExecHosts: models.Jsonb{String: `{"host_slots":[{"host_name":"t2","num_slots":1}],"num_hosts":1}`},
+	})
+	// Multi-host RUN job: one job on t1 + t3 counts on both.
+	store.Jobs.Put(3, models.JobInfo{
+		JobStatus: models.JOBSTAT["RUN"],
+		ExecHosts: models.Jsonb{String: `{"host_slots":[{"host_name":"t1","num_slots":1},{"host_name":"t3","num_slots":1}],"num_hosts":2}`},
+	})
+	// PEND and DONE jobs must NOT count.
+	store.Jobs.Put(4, models.JobInfo{
+		JobStatus: models.JOBSTAT["PEND"],
+		ExecHosts: models.Jsonb{String: `{"host_slots":[{"host_name":"t3","num_slots":1}],"num_hosts":1}`},
+	})
+	store.Jobs.Put(5, models.JobInfo{
+		JobStatus: models.JOBSTAT["DONE"],
+		ExecHosts: models.Jsonb{String: `{"host_slots":[{"host_name":"t1","num_slots":1}],"num_hosts":1}`},
+	})
+	// RUN job with empty/bad exec_hosts must not crash or count.
+	store.Jobs.Put(6, models.JobInfo{
+		JobStatus: models.JOBSTAT["RUN"],
+		ExecHosts: models.Jsonb{String: ``},
+	})
+	store.Jobs.Put(7, models.JobInfo{
+		JobStatus: models.JOBSTAT["RUN"],
+		ExecHosts: models.Jsonb{String: `not-json`},
+	})
+
+	counts := countRunningJobsPerHost()
+
+	if counts["t1"] != 2 { // jobs 1 + 3
+		t.Errorf("t1 running = %d, want 2", counts["t1"])
+	}
+	if counts["t2"] != 1 {
+		t.Errorf("t2 running = %d, want 1", counts["t2"])
+	}
+	if counts["t3"] != 1 { // job 3 only (job 4 is PEND)
+		t.Errorf("t3 running = %d, want 1", counts["t3"])
+	}
+	if _, ok := counts["nohost"]; ok {
+		t.Error("unexpected host 'nohost' in counts")
+	}
+}