# Update

## Update Cortex configuration

```bash
cortex cluster configure cluster.yaml
```

## Upgrade to a newer version of Cortex

```bash
# spin down your cluster
cortex cluster down --config cluster.yaml # or just pass in the name and region of the cluster

# update your CLI to the latest version
pip install --upgrade cortex

# confirm version
cortex version

# spin up your cluster
cortex cluster up cluster.yaml
```

## Upgrade without downtime

In production environments, you can upgrade your cluster without downtime if you have a backend service or DNS in front of your Cortex cluster:

1. Spin up a new cluster. For example: `cortex cluster up new-cluster.yaml --configure-env new` (this will create a CLI environment named `new` for accessing the new cluster).
2. Re-deploy your APIs in your new cluster. For example, if the name of your CLI environment for your old cluster is `old`, you can use `cortex get --env old` to list all running APIs in your old cluster, and re-deploy them in the new cluster by changing directories to each API's project folder and running `cortex deploy --env new`.
3. Route requests to your new cluster.
   * If you are using a custom domain: update the A record in your Route 53 hosted zone to point to your new cluster's API load balancer.
   * If you have a backend service which makes requests to Cortex: update your backend service to make requests to the new cluster's endpoints.
   * If you have a self-managed API Gateway in front of your Cortex cluster: update the routes to use new cluster's endpoints.
4. Spin down your old cluster. If you updated DNS settings, wait 24-48 hours before spinning down your old cluster to allow the DNS cache to be flushed.