Plugin scheduler: sequential iterations with max runtime (#8496)

* pb: add job type max runtime setting

* plugin: default job type max runtime

* plugin: redesign scheduler loop

* admin ui: update scheduler settings

* plugin: fix scheduler loop state name

* plugin scheduler: restore backlog skip

* plugin scheduler: drop legacy detection helper

* admin api: require scheduler config body

* admin ui: preserve detection interval on save

* plugin scheduler: use job context and drain cancels

* plugin scheduler: respect detection intervals

* plugin scheduler: gate runs and drain queue

* ec test: reuse req/resp vars

* ec test: add scheduler debug logs

* Adjust scheduler idle sleep and initial run delay

* Clear pending job queue before scheduler runs

* Log next detection time in EC integration test

* Improve plugin scheduler debug logging in EC test

* Expose scheduler next detection time

* Log scheduler next detection time in EC test

* Wake scheduler on config or worker updates

* Expose scheduler sleep interval in UI

* Fix scheduler sleep save value selection

* Set scheduler idle sleep default to 613s

* Show scheduler next run time in plugin UI

---------

Co-authored-by: Copilot <copilot@github.com>

weed/admin/dash/plugin_api.go

@@ -235,6 +235,53 @@ func (s *AdminServer) GetPluginSchedulerStatusAPI(w http.ResponseWriter, r *http
 	writeJSON(w, http.StatusOK, response)
 }
 
+// GetPluginSchedulerConfigAPI returns scheduler configuration.
+func (s *AdminServer) GetPluginSchedulerConfigAPI(w http.ResponseWriter, r *http.Request) {
+	pluginSvc := s.GetPlugin()
+	if pluginSvc == nil {
+		writeJSONError(w, http.StatusNotFound, "plugin is not enabled")
+		return
+	}
+
+	writeJSON(w, http.StatusOK, pluginSvc.GetSchedulerConfig())
+}
+
+// UpdatePluginSchedulerConfigAPI updates scheduler configuration.
+func (s *AdminServer) UpdatePluginSchedulerConfigAPI(w http.ResponseWriter, r *http.Request) {
+	pluginSvc := s.GetPlugin()
+	if pluginSvc == nil {
+		writeJSONError(w, http.StatusNotFound, "plugin is not enabled")
+		return
+	}
+
+	var req struct {
+		IdleSleepSeconds *int32 `json:"idle_sleep_seconds"`
+	}
+
+	if err := decodeJSONBody(newJSONMaxReader(w, r), &req); err != nil {
+		if errors.Is(err, io.EOF) {
+			writeJSONError(w, http.StatusBadRequest, "request body is required")
+			return
+		}
+		writeJSONError(w, http.StatusBadRequest, "invalid request body: "+err.Error())
+		return
+	}
+	if req.IdleSleepSeconds == nil {
+		writeJSONError(w, http.StatusBadRequest, "idle_sleep_seconds is required")
+		return
+	}
+
+	updated, err := pluginSvc.UpdateSchedulerConfig(plugin.SchedulerConfig{
+		IdleSleepSeconds: *req.IdleSleepSeconds,
+	})
+	if err != nil {
+		writeJSONError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	writeJSON(w, http.StatusOK, updated)
+}
+
 // RequestPluginJobTypeSchemaAPI asks a worker for one job type schema.
 func (s *AdminServer) RequestPluginJobTypeSchemaAPI(w http.ResponseWriter, r *http.Request) {
 	jobType := strings.TrimSpace(mux.Vars(r)["jobType"])
@@ -867,6 +914,9 @@ func applyDescriptorDefaultsToPersistedConfig(
 		if runtime.PerWorkerExecutionConcurrency <= 0 {
 			runtime.PerWorkerExecutionConcurrency = defaults.PerWorkerExecutionConcurrency
 		}
+		if runtime.JobTypeMaxRuntimeSeconds <= 0 {
+			runtime.JobTypeMaxRuntimeSeconds = defaults.JobTypeMaxRuntimeSeconds
+		}
 		if runtime.RetryBackoffSeconds <= 0 {
 			runtime.RetryBackoffSeconds = defaults.RetryBackoffSeconds
 		}