---
title: "Keep a function ready with dedicated replicas"
description: "Keep a set number of instances of a CPU or container function always running to avoid cold starts, with a minimum replica count."
content_type: "how-to"
product: "functions"
platform: "MyAccount"
url: "/myaccount/functions/how-to/keep-a-function-ready-with-dedicated-replicas/"
topic: ["create"]
relationships: {"requires":["/myaccount/functions/how-to/create-a-function/"]}
---

# Keep a function ready with dedicated replicas

Turn on **Enable Dedicated Replica** to keep a set number of instances of a function always
running. A request then reaches an instance that is already up. Without replicas, a request can
wait for an instance to start. That wait is a cold start.

Dedicated replicas add nothing to the bill. A replica waiting for requests is not charged. See
[Billing](/myaccount/functions/concepts/billing/).

## Before you begin

Dedicated replicas are available for CPU and container functions. See
[Runtimes and hardware](/myaccount/functions/concepts/runtimes-and-hardware/#hardware-choices).

You can change dedicated replicas while the function is **Running** or **Failed**.

## Turn on dedicated replicas

1. In **Compute > Functions**, click the function's name to open its page, and open the **System
   Configuration** tab.
2. Turn on **Enable Dedicated Replica**.
3. Set **Minimum Replica** to the number of instances to keep running, from 1 to 5. Start with 1.
4. Click **Save**.

You can also set dedicated replicas when you create the function. See
[Create a function](/myaccount/functions/how-to/create-a-function/).

## Check that the change applied

After you save, the function redeploys. Select the function in the Functions list and open the
**Info** tab below the list. The **Info** tab shows **Dedicated Replicas**, with the count you
set.

## Turn off dedicated replicas

1. On the function's page, open the **System Configuration** tab.
2. Turn off the dedicated replica checkbox beside **Minimum Replica**. The checkbox reads **Enable
   Dedicated Replica** again.
3. Click **Save**.

The function redeploys without dedicated replicas, and **Dedicated Replicas** on the **Info** tab
shows 0.

## What you have now

The function keeps the number of instances you set ready for requests. To change the count later,
see [Edit a function](/myaccount/functions/how-to/edit-a-function/).