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Table of Contents

Handbook

Configuring load-balancing (LB) methods

The system includes predefined configuration objects for all supported load balancing methods, and there is no need to create additional configuration objects. You may choose to do so, however, for various reasons, for example, to use a naming convention that makes the purpose of the configuration clear to other administrators.

Predefined LB methods describes the predefined methods.

Predefined LB methods

Predefined Description

LB_METHOD_ROUND_ROBIN

Selects the next server in the series: server 1, then server 2, then server 3, and so on.

LB_METHOD_LEAST_CONNECTION

Selects the server with the least connections.

LB_METHOD_FASTEST_RESPONSE

Selects the server with the fastest response to health check tests.

LB_METHOD_URI

Selects the server based on a hash of the URI found in the HTTP header, excluding hostname.

LB_METHOD_FULL_URI

Selects the server based on a hash of the full URI string found in the HTTP header. The full URI string includes the hostname and path.

LB_METHOD_HOST

Selects the server based on a hash of the hostname in the HTTP Request header Host field.

LB_METHOD_HOST_DOMAIN

Selects the server based on a hash of the domain name in the HTTP Request header Host field.

LB_METHOD_DEST_IP_HASH

Selects the next hop based on a hash of the destination IP address. This method can be used with the Layer 2 virtual server.

LB_METHOD_DYNAMIC_LOAD

Selects the server with the highest weight assigned to it based on its SNMP health check.

Note: Dynamic load-balancing is a load-balancing method in which FortiADC (the load-balancer) actively polls server pool members, and then assigns a weighted value to each member based on a set of default or user-defined thresholds. The value ranges from 1 to 256, and determines the amount of traffic FortiADC directs to a member. The greater the value that FortiADC assigns to a member, the more client requests it (the member) receives.

Dynamic load-balancing relies on the status of SNMP health check to calculate the load on each real server. The health check covers a real server's CPU, memory, and disk usage. When a real server has exceeded its health check thresholds, it will be marked as "down". If that happens, FortiADC will stop sending client requests to that server.

Before you begin:

  • You must have Read-Write permission for Load Balance settings.
To configure a load-balancing method configuration object:
  1. Go to Server Load Balance > Virtual Server > Application Resources.
  2. Click the LB Method tab.
  3. Click Create New to display the configuration editor.
  4. Give configuration object a name and select the load-balancing type.
  5. Save the configuration.

Configuring load-balancing (LB) methods

The system includes predefined configuration objects for all supported load balancing methods, and there is no need to create additional configuration objects. You may choose to do so, however, for various reasons, for example, to use a naming convention that makes the purpose of the configuration clear to other administrators.

Predefined LB methods describes the predefined methods.

Predefined LB methods

Predefined Description

LB_METHOD_ROUND_ROBIN

Selects the next server in the series: server 1, then server 2, then server 3, and so on.

LB_METHOD_LEAST_CONNECTION

Selects the server with the least connections.

LB_METHOD_FASTEST_RESPONSE

Selects the server with the fastest response to health check tests.

LB_METHOD_URI

Selects the server based on a hash of the URI found in the HTTP header, excluding hostname.

LB_METHOD_FULL_URI

Selects the server based on a hash of the full URI string found in the HTTP header. The full URI string includes the hostname and path.

LB_METHOD_HOST

Selects the server based on a hash of the hostname in the HTTP Request header Host field.

LB_METHOD_HOST_DOMAIN

Selects the server based on a hash of the domain name in the HTTP Request header Host field.

LB_METHOD_DEST_IP_HASH

Selects the next hop based on a hash of the destination IP address. This method can be used with the Layer 2 virtual server.

LB_METHOD_DYNAMIC_LOAD

Selects the server with the highest weight assigned to it based on its SNMP health check.

Note: Dynamic load-balancing is a load-balancing method in which FortiADC (the load-balancer) actively polls server pool members, and then assigns a weighted value to each member based on a set of default or user-defined thresholds. The value ranges from 1 to 256, and determines the amount of traffic FortiADC directs to a member. The greater the value that FortiADC assigns to a member, the more client requests it (the member) receives.

Dynamic load-balancing relies on the status of SNMP health check to calculate the load on each real server. The health check covers a real server's CPU, memory, and disk usage. When a real server has exceeded its health check thresholds, it will be marked as "down". If that happens, FortiADC will stop sending client requests to that server.

Before you begin:

  • You must have Read-Write permission for Load Balance settings.
To configure a load-balancing method configuration object:
  1. Go to Server Load Balance > Virtual Server > Application Resources.
  2. Click the LB Method tab.
  3. Click Create New to display the configuration editor.
  4. Give configuration object a name and select the load-balancing type.
  5. Save the configuration.