The ANS network load balancer provides the following main functions:
Virtual service and application high availability
Traffic can be forwarded to multiple backend servers through load balancing. Even if one backend server fails, other servers can continue to provide services.
Two server pools can be combined into a server pool group. If all members in the primary server pool fail, members in the secondary server pool can take over.
Each virtual service is provided with high availability by two load balancer virtual machines within an LB instance in a primary-secondary configuration, preventing service unavailability caused by single points of failure. To further enhance reliability, an LB instance group can be used to prevent service unavailability caused by the failure of an entire LB instance.
Rich set of load balancing algorithms
Six load balancing algorithms are supported: round robin, weighted round robin, least connection, weighted least connection, source IP address hash, and destination IP address hash, flexibly meeting load balancing requirements across different scenarios.
Proactive health checks
Four proactive health check methods are supported: TCP, HTTP, UDP, and ICMP, which can periodically check the health status of backend servers.
When a backend server is detected as abnormal, client requests are automatically forwarded to other healthy backend servers. When the abnormal backend server returns to normal, it is automatically restored to the load balancing service to continue handling traffic.
Session persistence
All connections with the same source address can be sent to the same backend server within a specific time period, ensuring session continuity and stability.
Traffic control
The peak ingress and egress traffic handled by a virtual service can be flexibly controlled, preventing any single virtual service from consuming excessive network bandwidth and enabling reasonable resource allocation.
Client access control
Client IP addresses can be allowed or blocked using allowlists or blocklists, effectively protecting virtual service resources, preventing malicious requests, and thus improving the security and robustness of the load balancer.
Concurrent connection control
The number of concurrent connections a client is allowed to establish with a virtual service at any one time can be flexibly limited, preventing excessive resource consumption caused by malicious attacks.
