Load balancing strategies are used in a site configuration to distribute the load between multiple backend target servers. Load balancing settings are optional and only available if more than one target is listed for a site.
This functionality can replace a load balancer appliance between the PingAccess engine nodes and the target servers, allowing for a simpler network architecture.
Available load balancing strategies:
- Header-Based
- The header-based strategy requires incoming requests to include a header that defines the target to select from the Site configuration. This load balancing strategy allows fall back if the requested target is unavailable or if the header is missing from the request.
- Round-Robin
- The round-robin strategy has a sticky session option that permits a browser session to be pinned to a persistent backend target. This strategy works in conjunction with the availability profile to select a target based on its availability. The load balancer will not select a target that is in a failed state.
If you specify multiple target servers for a site but don't apply a load balancing strategy, PingAccess uses the first target server in the list until it fails. Secondary target servers are only used if the first target server is not available. PingAccess uses the Failed Retry Timeout value from the site's availability profile settings to determine when to mark the first target server as available again.
Configuring load balancing strategies
To create and configure a new load balancing strategy in PingAccess:
- Click Settings and then go to .
- Click + Add Load Balancing Strategy.
- In the Name field, enter a unique descriptive name for the strategy.
-
In the Type list, select one of the following strategy
types:
- Header-Based
- Round Robin
-
Configure the options for the selected load balancing strategy type.
- For a Header-Based load balancing strategy:
- In the Header Name field, enter the name of the header that contains the selected target host.
- To configure PingAccess to use the first
available target defined for the site, click Show
Advanced and select the Fall Back to
First Available Host option if the target specified
in the header is not available or if the header is not present in
the request.Note:
If this option isn't enabled, and the specified target isn't available or the request header isn't present, the client receives a Service Unavailable response.
- For a Round Robin load balancing strategy:
- If browser sessions shouldn't be pinned to a persistent backend
target, clear the Sticky Session Enabled
check box.
This check box is selected by default.
- If Sticky Session Enabled is selected, enter
a cookie name to use in the Cookie Name
field.
The PingAccess engine uses this cookie to track the persistent backend targets for a session.
Note:When you define a web session, the Cookie Name field defines a cookie prefix to use. The rest of the cookie name comes from the Audience field in the web session.
- If browser sessions shouldn't be pinned to a persistent backend
target, clear the Sticky Session Enabled
check box.
- For a Header-Based load balancing strategy:
- Click Save.
Editing load balancing strategies
To edit the properties of an existing load balancing strategy in PingAccess:
- Click Settings and then go to .
- Click the Expand icon to see more details about the load balancing strategy that you want to edit.
- Click the Pencil icon.
- Make any desired changes to the properties.
- Click Save.
Deleting load balancing strategies
To delete an existing load balancing strategy in PingAccess:
- Click Settings and then go to .
- Click the Expand icon to see more details about the load balancing strategy that you want to delete.
- Click the Delete icon.
- Click Delete.