Remove blocking CollectNow commands to fix heartbeat stability

Eliminates automatic CollectNow command sending on host connection which
was blocking the main message processing loop for up to 5 seconds per
command. Since agents transmit cached data every 2 seconds anyway, the
CollectNow optimization provided minimal benefit while causing heartbeat
detection issues. Also removes unused send_command wrapper method.

This should completely resolve intermittent host connection dropping.

.gitea/workflows/release.yml

@@ -113,13 +113,13 @@ jobs:
           NIX_HASH="sha256-$(python3 -c "import base64, binascii; print(base64.b64encode(binascii.unhexlify('$NEW_HASH')).decode())")"
           
           # Update the NixOS configuration
-          sed -i "s|version = \"v[^\"]*\"|version = \"$VERSION\"|" hosts/common/cm-dashboard.nix
+          sed -i "s|version = \"v[^\"]*\"|version = \"$VERSION\"|" hosts/services/cm-dashboard.nix
-          sed -i "s|sha256 = \"sha256-[^\"]*\"|sha256 = \"$NIX_HASH\"|" hosts/common/cm-dashboard.nix
+          sed -i "s|sha256 = \"sha256-[^\"]*\"|sha256 = \"$NIX_HASH\"|" hosts/services/cm-dashboard.nix
           
           # Commit and push changes
           git config user.name "Gitea Actions"
           git config user.email "actions@gitea.cmtec.se"
-          git add hosts/common/cm-dashboard.nix
+          git add hosts/services/cm-dashboard.nix
           git commit -m "Auto-update cm-dashboard to $VERSION
 
           - Update version to $VERSION with automated release

CLAUDE.md

@@ -115,7 +115,7 @@ This automatically:
 - Uploads binaries via Gitea API
 
 ### NixOS Configuration Updates
-Edit `~/projects/nixosbox/hosts/common/cm-dashboard.nix`:
+Edit `~/projects/nixosbox/hosts/services/cm-dashboard.nix`:
 
 ```nix
 version = "v0.1.X";

Cargo.lock

@@ -270,7 +270,7 @@ checksum = "a1d728cc89cf3aee9ff92b05e62b19ee65a02b5702cff7d5a377e32c6ae29d8d"
 
 [[package]]
 name = "cm-dashboard"
-version = "0.1.67"
+version = "0.1.72"
 dependencies = [
  "anyhow",
  "chrono",
@@ -292,7 +292,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-agent"
-version = "0.1.67"
+version = "0.1.72"
 dependencies = [
  "anyhow",
  "async-trait",
@@ -315,7 +315,7 @@ dependencies = [
 
 [[package]]
 name = "cm-dashboard-shared"
-version = "0.1.67"
+version = "0.1.72"
 dependencies = [
  "chrono",
  "serde",

README.md

@@ -329,7 +329,7 @@ This triggers automated:
 - Tarball upload to Gitea
 
 ### NixOS Integration
-Update `~/projects/nixosbox/hosts/common/cm-dashboard.nix`:
+Update `~/projects/nixosbox/hosts/services/cm-dashboard.nix`:
 
 ```nix
 version = "v0.1.43";

agent/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard-agent"
-version = "0.1.68"
+version = "0.1.73"
 edition = "2021"
 
 [dependencies]

agent/src/agent.rs

@@ -351,36 +351,40 @@ impl Agent {
             _ => {}
         }
 
-        let output = tokio::process::Command::new("sudo")
+        // Spawn the systemctl command asynchronously to avoid blocking the agent
-            .arg("systemctl")
+        let service_name_clone = service_name.to_string();
-            .arg(action_str)
+        let action_str_clone = action_str.to_string();
-            .arg(format!("{}.service", service_name))
-            .output()
-            .await?;
         
+        tokio::spawn(async move {
+            let result = tokio::process::Command::new("sudo")
+                .arg("systemctl")
+                .arg(&action_str_clone)
+                .arg(format!("{}.service", service_name_clone))
+                .output()
+                .await;
+
+            match result {
+                Ok(output) => {
                     if output.status.success() {
-            info!("Service {} {} completed successfully", service_name, action_str);
+                        info!("Service {} {} completed successfully", service_name_clone, action_str_clone);
                         if !output.stdout.is_empty() {
                             debug!("stdout: {}", String::from_utf8_lossy(&output.stdout));
                         }
-            
-            // Note: User-stopped flag will be cleared by systemd collector 
-            // when service actually reaches 'active' state, not here
                     } else {
                         let stderr = String::from_utf8_lossy(&output.stderr);
-            error!("Service {} {} failed: {}", service_name, action_str, stderr);
+                        error!("Service {} {} failed: {}", service_name_clone, action_str_clone, stderr);
-            return Err(anyhow::anyhow!("systemctl {} {} failed: {}", action_str, service_name, stderr));
                     }
+                }
+                Err(e) => {
+                    error!("Failed to execute systemctl {} {}: {}", action_str_clone, service_name_clone, e);
+                }
+            }
+        });
 
-        // Force refresh metrics after service control to update service status
+        info!("Service {} {} command initiated (non-blocking)", service_name, action_str);
-        if matches!(action, ServiceAction::Start | ServiceAction::Stop | ServiceAction::UserStart | ServiceAction::UserStop) {
+
-            info!("Triggering immediate metric refresh after service control");
+        // Note: Service status will be updated by the normal metric collection cycle
-            if let Err(e) = self.collect_metrics_only().await {
+        // once the systemctl operation completes
-                error!("Failed to refresh metrics after service control: {}", e);
-            } else {
-                info!("Service status refreshed immediately after {} {}", action_str, service_name);
-            }
-        }
 
         Ok(())
     }

dashboard/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard"
-version = "0.1.68"
+version = "0.1.73"
 edition = "2021"
 
 [dependencies]

dashboard/src/app.rs

@@ -134,12 +134,6 @@ impl Dashboard {
         })
     }
 
-    /// Send a command to a specific agent
-    pub async fn send_command(&mut self, hostname: &str, command: AgentCommand) -> Result<()> {
-        self.zmq_command_sender
-            .send_command(hostname, command)
-            .await
-    }
 
     pub async fn run(&mut self) -> Result<()> {
         info!("Starting dashboard main loop");
@@ -212,35 +206,19 @@ impl Dashboard {
                         metric_message.metrics.len()
                     );
 
-                    // Check if this is the first time we've seen this host
+                    // Track first contact with host (no command needed - agent sends data every 2s)
                     let is_new_host = !self
                         .initial_commands_sent
                         .contains(&metric_message.hostname);
 
                     if is_new_host {
                         info!(
-                            "First contact with host {}, sending initial CollectNow command",
+                            "First contact with host {} - data will update automatically",
-                            metric_message.hostname
-                        );
-
-                        // Send CollectNow command for immediate refresh
-                        if let Err(e) = self
-                            .send_command(&metric_message.hostname, AgentCommand::CollectNow)
-                            .await
-                        {
-                            error!(
-                                "Failed to send initial CollectNow command to {}: {}",
-                                metric_message.hostname, e
-                            );
-                        } else {
-                            info!(
-                                "✓ Sent initial CollectNow command to {}",
                             metric_message.hostname
                         );
                         self.initial_commands_sent
                             .insert(metric_message.hostname.clone());
                     }
-                    }
 
                     // Update metric store
                     self.metric_store

dashboard/src/communication/mod.rs

@@ -84,6 +84,7 @@ impl ZmqConsumer {
         }
     }
 
+
     /// Connect to predefined hosts using their configuration
     pub async fn connect_to_predefined_hosts(&mut self, hosts: &std::collections::HashMap<String, crate::config::HostDetails>) -> Result<()> {
         let default_port = self.config.subscriber_ports[0];
@@ -104,27 +105,13 @@ impl ZmqConsumer {
         Ok(())
     }
 
-    /// Connect to a host using its configuration details with fallback support
+    /// Connect to a host using its configuration details
     pub async fn connect_to_host_with_details(&mut self, hostname: &str, host_details: &crate::config::HostDetails, port: u16) -> Result<()> {
-        // Get primary connection IP
+        // Get primary connection IP only - no fallbacks
         let primary_ip = host_details.get_connection_ip(hostname);
         
-        // Try primary connection
+        // Connect directly without fallback attempts
-        if let Ok(()) = self.connect_to_host(&primary_ip, port).await {
+        self.connect_to_host(&primary_ip, port).await
-            info!("Connected to {} via primary address: {}", hostname, primary_ip);
-            return Ok(());
-        }
-        
-        // Try fallback IPs if primary fails
-        let fallbacks = host_details.get_fallback_ips(hostname);
-        for fallback_ip in fallbacks {
-            if let Ok(()) = self.connect_to_host(&fallback_ip, port).await {
-                info!("Connected to {} via fallback address: {}", hostname, fallback_ip);
-                return Ok(());
-            }
-        }
-        
-        Err(anyhow::anyhow!("Failed to connect to {} using all available addresses", hostname))
     }
 
     /// Receive command output from any connected agent (non-blocking)  

dashboard/src/config/mod.rs

@@ -31,75 +31,15 @@ pub struct HostDetails {
     pub mac_address: Option<String>,
     /// Primary IP address (local network)
     pub ip: Option<String>,
-    /// Tailscale network IP address
-    pub tailscale_ip: Option<String>,
-    /// Preferred connection type: "local", "tailscale", or "auto" (fallback)
-    #[serde(default = "default_connection_type")]
-    pub connection_type: String,
 }
 
-fn default_connection_type() -> String {
-    "auto".to_string()
-}
 
 impl HostDetails {
-    /// Get the preferred IP address for connection based on connection_type
+    /// Get the IP address for connection (uses ip field or hostname as fallback)
     pub fn get_connection_ip(&self, hostname: &str) -> String {
-        match self.connection_type.as_str() {
-            "tailscale" => {
-                if let Some(ref ts_ip) = self.tailscale_ip {
-                    ts_ip.clone()
-                } else {
-                    // Fallback to local IP or hostname
         self.ip.as_ref().unwrap_or(&hostname.to_string()).clone()
     }
-            }
-            "local" => {
-                if let Some(ref local_ip) = self.ip {
-                    local_ip.clone()
-                } else {
-                    hostname.to_string()
-                }
-            }
-            "auto" | _ => {
-                // Try tailscale first, then local, then hostname
-                if let Some(ref ts_ip) = self.tailscale_ip {
-                    ts_ip.clone()
-                } else if let Some(ref local_ip) = self.ip {
-                    local_ip.clone()
-                } else {
-                    hostname.to_string()
-                }
-            }
-        }
-    }
 
-    /// Get fallback IP addresses for connection retry
-    pub fn get_fallback_ips(&self, hostname: &str) -> Vec<String> {
-        let mut fallbacks = Vec::new();
-        
-        // Add all available IPs except the primary one
-        let primary = self.get_connection_ip(hostname);
-        
-        if let Some(ref ts_ip) = self.tailscale_ip {
-            if ts_ip != &primary {
-                fallbacks.push(ts_ip.clone());
-            }
-        }
-        
-        if let Some(ref local_ip) = self.ip {
-            if local_ip != &primary {
-                fallbacks.push(local_ip.clone());
-            }
-        }
-        
-        // Always include hostname as final fallback if not already primary
-        if hostname != primary {
-            fallbacks.push(hostname.to_string());
-        }
-        
-        fallbacks
-    }
 }
 
 /// System configuration

shared/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard-shared"
-version = "0.1.68"
+version = "0.1.73"
 edition = "2021"
 
 [dependencies]