Updated on 2024-04-19 GMT+08:00

Specifications of Dedicated Load Balancers

Load balancers are available in different specifications. Choose the specifications that best meet your needs. If the traffic exceeds the selected specifications, new requests will be discarded.

  • Connections per second (CPS)

    Indicates the number of new connections that a load balancer can establish per second. If the number reaches the CPS that is defined in the specification, new requests will be discarded to ensure the performance of established connections.

    HTTPS listeners need to create SSL handshakes to establish connections with clients, and such SSL handshakes occupy more system resources than HTTP listeners. For example, a small I application load balancer can establish 2,000 new HTTP connections per second but only 200 new HTTPS connections per second.

    For a small I application load balancer:

    • If you only add an HTTP listener, the load balancer can establish up to 2,000 new HTTP connections.
    • If you only add an HTTPS listener, the load balancer can establish up to 200 new HTTPS connections.
    • If you add an HTTPS listener and an HTTP listener, the new connections are calculated using the following formula:

      New connections = New HTTP connections + New HTTPS connections x Ratio of HTTP connections to HTTPS connections

      For a small I application load balancer, the ratio of HTTP connections to HTTPS connections is 10. For details, see Table 1.

      Table 1 New connections that a small I application load balancer can establish

      Parameter

      Scenario 1

      Scenario 2

      New HTTP connections

      1,000

      1,000

      New HTTPS connections

      50

      150

      New HTTP and HTTPS connections

      1,000 + 50 x 10 = 1,500

      1,000 + 150 x 10 = 2,500

      Description

      The new connections do not reach the CPS (HTTP) defined in Table 2, and new requests can be properly routed.

      The new connections reach the CPS (HTTP) defined in Table 2, and new requests will be discarded.

      Details in Table 1 are for reference only.

  • Maximum concurrent connections

    Indicates the maximum number of concurrent connections that a load balancer can handle. If the number reaches the maximum concurrent connections that is defined in the specification, new requests will be discarded to ensure the performance of the established connections.

  • Queries per second (QPS)

    Indicates the number of HTTP or HTTPS requests sent to a backend server per second. If the QPS reaches that is defined in the specification, new requests will be discarded to ensure the performance of established connections.

  • Bandwidth (Mbit/s)

    Indicates the maximum amount of data that can be transmitted over a connection per second.

Table 2 and Table 3 list the specifications of s.

  • Available fixed specifications are displayed on the console and may vary depending on the resources in different regions.
  • The load balancing type cannot be changed after being selected.

    For example, after you select network load balancing, you cannot change it to application load balancing. You can add only TCP and UDP listeners and cannot add HTTP and HTTPS listeners.

Table 2 Specifications for application load balancing (HTTP/HTTPS)

Type

Maximum Concurrent Connections

CPS (HTTP)

CPS (HTTPS)

QPS

Small I

200,000

2,000

200

4,000

Small II

400,000

4,000

400

8,000

Medium I

800,000

8,000

800

16,000

Medium II

2,000,000

20,000

2,000

40,000

Large I

4,000,000

40,000

4,000

80,000

Large II

8,000,000

80,000

8,000

160,000

Table 3 Specifications for network load balancing (TCP/UDP)

Type

CPS

Maximum Concurrent Connections

Small I

10,000

500,000

Small II

20,000

1,000,000

Medium I

40,000

2,000,000

Medium II

80,000

4,000,000

Large I

200,000

10,000,000

Large II

400,000

20,000,000