Network Load Balancer (NLB) is a Layer 4 load balancing service from Alibaba Cloud, built for the Internet of Things (IoT) era. It delivers ultra-high performance and automatic scaling. A single NLB instance supports up to 100 million concurrent connections, enabling you to manage high-concurrency services efficiently. NLB performance and limits
Benefits
Ultra-high performance
An NLB instance supports ultra-high concurrent connections and massive bandwidth, helping you handle burst traffic and high-concurrency demands from industries such as the internet, AI, and embodied intelligence.
Automatic scaling
You do not need to specify or manually adjust the instance type of an NLB instance. Performance automatically scales with your business traffic.
High availability
NLB uses a multi-level disaster recovery architecture. It ensures instance availability through cluster-level disaster recovery, session persistence, and multi-zone deployment.
TCP SSL offloading
NLB supports large-scale TCP SSL offloading. You can centrally manage and offload SSL certificates on NLB, improving the processing efficiency of backend services.
Multi-scenario traffic distribution
NLB supports backend servers of the IP address type. You can use NLB with Cloud Enterprise Network (CEN) to distribute and schedule traffic across regions, across VPCs, and to on-premises data centers.
Rich advanced features
NLB supports advanced features such as IPv4/IPv6 dual-stack, all-port listeners, new connection rate limits, and connection draining to meet your custom business needs.
Scenarios
Ingress for IoT services
In scenarios such as smart homes, smart parking, video surveillance, and the Internet of Vehicles (IoV), NLB acts as a service ingress that handles massive concurrent connections. It also provides TCP SSL offloading and connection rate limits to ensure the security and stability of IoT services.
Ingress for cloud services on the internet
NLB acts as an ingress for internet traffic. A single instance delivers powerful Layer 4 processing capabilities and automatically scales based on traffic changes. No manual intervention is needed during traffic fluctuations, reducing operations and management costs.
Ingress for hybrid cloud services
NLB supports on-premises data center (IDC) servers as backend servers. You can use NLB with products such as CEN to forward cloud requests to on-premises servers, enabling seamless communication between on-premises IDCs and cloud services.
NLB components
Concept | Description |
Instance | NLB provides powerful Layer 4 load balancing capabilities. It distributes traffic to different backend servers to increase the throughput of your applications. A single instance supports up to 100 million concurrent connections. |
Listener | A listener is the smallest service unit of NLB. You must configure a protocol and port for a listener to specify the traffic that NLB needs to process, such as TCP traffic on port 80. NLB supports the TCP, UDP, and TCP SSL protocols. Each NLB instance must have at least one listener to process and distribute traffic. For information about the maximum number of listeners that you can configure for each NLB instance, see NLB quotas. |
Server group | A server group is a logical group that contains multiple backend servers to process requests distributed by NLB. Server groups in NLB are independent of NLB instances. You can attach the same server group to different NLB instances. For information about the maximum number of backend servers that you can add to a server group, see NLB quotas. NLB server groups support Elastic Compute Service (ECS) instances, Elastic Container Instance (ECI) instances, elastic network interfaces (ENIs), and backend servers of the IP address type. For more information, see: |
Health check | NLB performs health checks to determine the service availability of backend servers. NLB detects unhealthy servers in a server group and stops distributing traffic to the unhealthy servers. NLB supports flexible health check configurations, such as protocols, ports, and various health check thresholds. |
NLB types
This section describes the network types and protocol versions of NLB. The following figure shows dual-stack Internet-facing NLB instances and dual-stack internal-facing NLB instances.
Network types
Alibaba Cloud provides Internet-facing and private NLB instances. You can configure an Internet-facing or private NLB instance based on your business scenario. The system determines whether to use Internet Shared Bandwidth and elastic IP addresses (EIPs) based on your selection. In the preceding figure, all elements in the translucent box represent an Internet-facing (private) NLB instance.
Concept | Description |
Domain name | A domain name that is resolvable on the internet (private network) is resolved to the corresponding VIP. You can also map a custom domain name to the default domain name of the NLB instance using a CNAME record. Note Starting from November 15, 2024, 00:00:00 (UTC+8), new NLB instances will use new default domain names, and the Alibaba Cloud platform will not allow users to directly access using the default domain names provided by the platform. NLB instances created before November 15, 2024, 00:00:00 (UTC+8) are not affected. For more information, see Server Load Balancer Domain Name Upgradation Announcement. |
Internet Shared Bandwidth | You need to use Internet Shared Bandwidth only when you create an Internet-facing NLB instance. Internet Shared Bandwidth provides region-level bandwidth sharing and reuse capabilities, and offers multiple billing methods, such as pay-by-bandwidth and pay-by-enhanced-95th-percentile, to help you reduce Internet bandwidth costs. Internet-facing NLB instances use Internet Shared Bandwidth to provide the pay-by-bandwidth and pay-by-enhanced-95th-percentile billing methods. |
EIP | You need to use EIPs only when creating an Internet-facing NLB, and no configuration is required when creating an internal-facing NLB. An EIP is the IP address that NLB uses to provide services over the Internet. An Internet-facing NLB can use multiple EIPs. To ensure high availability, an Internet-facing NLB must use at least two EIPs in different zones. |
VIP (Virtual IP address) | The entity that NLB uses to distribute traffic. Each VIP is a private IP address in a virtual private cloud (VPC). |
Protocol Version
NLB supports IPv4 and dual-stack IP versions.
Concept | Description |
IPv4 | An IPv4 instance provides an IPv4 VIP. |
Dual-stack | A dual-stack instance provides both an IPv4 VIP and an IPv6 VIP. Each instance provides services through a unified domain name. |
Activate Network Load Balancer NLB
Click or Create a Network Load Balancer (NLB) to go directly to the NLB product purchase page.
Deploy and manage NLB
After you register an Alibaba Cloud account, you can deploy and manage NLB in the following ways:
Network Load Balancer (NLB) console: A web-based service page that provides an interactive user interface. You can log on to the console to create, use, or release NLB instances. For more information, see Create and manage an NLB instance.
Alibaba Cloud SDK: Provides SDKs for multiple programming languages, such as Java, Go, and Python.
OpenAPI Developer Portal: Provides services such as quick API retrieval, online API calls, and dynamic generation of SDK example code.
Terraform: An open source tool that you can use to call and manage compute resources on Alibaba Cloud and other cloud platforms that support Terraform using configuration files. Terraform also supports versioning.