Implement simple persistent cache with automatic saving on status changes

agent/src/status/mod.rs

@@ -9,7 +9,6 @@ use chrono::Utc;
 pub struct HostStatusConfig {
     pub enabled: bool,
     pub aggregation_method: String, // "worst_case"
-    pub update_interval_seconds: u64,
     pub notification_interval_seconds: u64,
 }
 
@@ -18,7 +17,6 @@ impl Default for HostStatusConfig {
         Self {
             enabled: true,
             aggregation_method: "worst_case".to_string(),
-            update_interval_seconds: 5,
             notification_interval_seconds: 30,
         }
     }
@@ -72,7 +70,7 @@ impl HostStatusManager {
 
     /// Update the status of a specific service and recalculate host status
     /// Updates real-time status and buffers changes for email notifications
-    pub fn update_service_status(&mut self, service: String, status: Status) {
+    pub fn update_service_status(&mut self, service: String, status: Status, cache_manager: Option<&crate::cache::MetricCacheManager>) {
         if !self.config.enabled {
             return;
         }
@@ -84,6 +82,14 @@ impl HostStatusManager {
             return;
         }
 
+        // Save cache when status changes (clone cache manager reference for async)
+        if let Some(cache) = cache_manager {
+            let cache = cache.clone();
+            tokio::spawn(async move {
+                cache.save_to_disk().await;
+            });
+        }
+
         // Initialize batch if this is the first change
         if self.batch_start_time.is_none() {
             self.batch_start_time = Some(Instant::now());
@@ -163,9 +169,9 @@ impl HostStatusManager {
 
 
     /// Process a metric - updates status (notifications handled separately via batching)
-    pub async fn process_metric(&mut self, metric: &Metric, _notification_manager: &mut crate::notifications::NotificationManager) {
+    pub async fn process_metric(&mut self, metric: &Metric, _notification_manager: &mut crate::notifications::NotificationManager, cache_manager: &crate::cache::MetricCacheManager) {
         // Just update status - notifications are handled by process_pending_notifications
-        self.update_service_status(metric.name.clone(), metric.status);
+        self.update_service_status(metric.name.clone(), metric.status, Some(cache_manager));
     }
 
     /// Process pending notifications - call this at notification intervals