scale to zero doc

src/data/sidebar.ts

@@ -84,6 +84,7 @@ export const sidebarContent: ISidebarContent = [
       makePage("Volumes", "reference"),
       makePage("Cron Jobs", "reference"),
       makePage("Pricing", "reference"),
+      makePage("Scale to Zero", "reference"),
       makePage("Usage Limits", "reference"),
       makePage("Accounts", "reference"),
       makePage("Teams", "reference"),

src/docs/reference/scale-to-zero.md

@@ -0,0 +1,49 @@
+---
+title: Scale to Zero
+---
+
+Scale to Zero means reducing unnecessary costs by ensuring you only use what you need, when you need it.
+
+## What is App Sleeping?
+
+App sleeping enables automated detection of an inactive [service](/develop/services) based on outbound traffic.
+
+Enabling App Sleep on a service tells Railway to stop the service when it is inactive, effectively reducing the overall cost to run it.
+
+<Image src="https://res.cloudinary.com/railway/image/upload/v1696017787/events_gjkaob.png"
+alt="App Sleeping in the Activity Feed"
+layout="intrinsic"
+width={700} height={460} quality={100} />
+
+### Inactive Service Detection
+
+Inactivity is based on outbound packets. If no packets are sent from the service for over 10 minutes or longer, the service is considered inactive.
+
+
+### Reactivation
+
+When the service receives traffic from the _public network*_, it is sent a signal to wake.  
+
+Only when the service is ready, is traffic routed to it, ensuring no requests are dropped during the startup process.
+
+_*Currently, requests made to the service over the private network do not cause it to awake from sleep._
+
+## How to enable App Sleeping
+
+To enable App Sleeping simply toggle the feature on within the service configuration - 
+
+<Image src="https://res.cloudinary.com/railway/image/upload/v1696548703/docs/scale-to-zero/appSleep_ksaewp.png"
+alt="Enable App Sleep"
+layout="intrinsic"
+width={700} height={460} quality={100} />
+
+1. Navigate to your service's settings > Deploy > App Sleeping.
+2. Toggle "Enable App Sleeping".
+3. This setting will be applied across all [replicas](https://docs.railway.app/develop/services#horizontal-scaling-with-replicas) automatically.
+4. When your service is put to sleep, an event will be visible in the dashboard.
+5. To _disable_ App Sleeping, simply toggle the setting again.
+
+## Things to Note
+- **Latency** - There may be a small delay when requests arrive at a stopped application.
+- **Private Networking** - Services that receive traffic exclusively over the private network should *not* be enabled with App Sleeping since only public network traffic will trigger the service to wake.
+- **Conditions for Sleeping** - For a service to be considered inactive, it must not send outbound traffic for at least 10 minutes or more.  Outbound traffic can include telemetry, NTP, etc.