Guides - Create a NodeBalancer
Managed cloud-based load balancing service that provides high availability and horizontal scaling to any application.
This guide walks you through creating a NodeBalancer through the Cloud Manager.
- Open the Create NodeBalancer Form in the Cloud Manager
- Set the Label
- Select a Region
- Add and Configure Ports
- Set Up Health Checks for Each Port
- Add Backend Nodes to Each Port
- Deploy the NodeBalancer
Within the Label field, enter the label you wish to use to identify it from other NodeBalancers on your account. A good label should provide some indication as to what the NodeBalancer will be used for. The label must be alphanumeric, between 3 and 32 characters, and unique from other NodeBalancer labels on your account.
Select the region where the NodeBalancer will reside. Regions correspond with individual data centers, each located in a different geographical area. Select the region where you’ve deployed the Compute Instances you intend on using with this NodeBalancer. If you haven’t yet deployed Compute Instances or chosen a region, select the region closest to you and/or your customers. This helps reduce latency and can make a significant impact in connection speeds and quality.
To start load balancing traffic, you need to define which ports the NodeBalancer should listen to and how the incoming traffic should be routed to the backend nodes. These ports can be configured within the NodeBalancer Settings area. By default, a single port configuration is visible in this area. Additional ports can be added by clicking the Add another Configuration button. See Configuration Options for more details regarding each of these settings.
- Port: Enter the inbound port the NodeBalancer should listen to. This can be any port from 1 through 65534 and should align with the port the client connects to. See Configuration Options > Port.
- Protocol: Select TCP, HTTP, or HTTPS. For many applications, using TCP offers the most flexibility and allows for TLS pass through. Using HTTP and HTTPS offers some additional NodeBalancer options and allows for TLS termination. See Configuration Options > Protocol.
- Proxy Protocol: Only visible when the TCP protocol is selected. Used for sending the client IP address to the backend nodes. See Configuration Options > Proxy Protocol.
- Algorithm: Controls how new connections are allocated across backend nodes. See Configuration Options > Algorithm.
- Session Stickiness: Controls how subsequent requests from the same client are routed when selecting a backend node. See Configuration Options > Session Stickiness.
Each port can optionally be configured with health checks. These health checks either proactively query the backend nodes (active) or monitor the existing traffic to backend nodes (passive). If a health check determines that the backends aren’t responsive or are encountering another issue, they can be marked as down and taken out of rotation.
Active Health Checks: Active health checks proactively query the backend nodes by performing TCP connections or making HTTP requests. See Configuration Options > Active Health Checks.
Passive Checks: Passive health checks monitor requests sent to the backend nodes and look for any issues. See Configuration Options > Passive Health Checks.
Load balancers work by distributing traffic to a pool of servers. For NodeBalancers, these servers are Linode Compute Instances and they are configured as backend nodes. Within the Backend Nodes area of the creation form, add each Compute Instance you intend on using with this NodeBalancer, making sure to select the correct private IP address for the NodeBalancer and the port that the application is using. For information on configuring backend nodes, see the Configure Backend Nodes (Compute Instances) guide.
Once you’ve adjusted the settings to fit your needs, review the NodeBalancer Summary section and click the Create NodeBalancer button. The NodeBalancer should be provisioned within a few minutes.
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