Configure ORS Load Balancing

Important

Starting in version 8.5.219, GMS requires Orchestration Server (ORS) version 8.1.300.30 and higher to send requests to the ORS /hearbeat URI.

Supported ORS Load Balancing Features

Genesys Mobile Services (GMS) supports the following load balancing features:

• Ability to configure a list of service URLs to access a given list of nodes.
• Linear hunt strategy where requests are always delivered to the first available node in the list.
• Circular hunt strategy where requests are delivered in a round-robin fashion to the list of nodes/URLs. Note that the Circular strategy automatically takes into account ORS and ORS backups.
• Ability to configure a linear hunt strategy or a circular hunt strategy in the service configuration. The default hunt mode is circular.

How to set up GMS connections to ORS?

Genesys recommends that you add a list of ORS primary servers to the Connections tab in case GMS should fall back to other nodes on failure.

GMS will automatically find the ORS backup servers and add them to the load balancing strategy; however, when failing on one node, GMS will try the next ORS node in the list, regardless if it is a primary or a backup server.

This default hunt strategy is circular. To modify this strategy, edit the _ors_lb_strategy option in the ors section.

When to Disable ORS Load-Balancing?

If the ORS is too old—check the Prerequisites, you can use the enable_ors_loadbalancer option to disable load-balancing in the ors section.

More ORS Load Balancing Settings

The following settings can be defined at the cluster or node level in the ors section of your GMS application. You cannot supersede these settings at the service level:

• max_ors_idle_connection_time
• New in 8.5.219
  • healthcheck-ping-url
  • healthcheck-ping-interval
• Deprecated in 8.5.219
  • ors_loadbalancer_refresh_rate

Important

If you do not update your configuration with the new options, GMS uses the deprecated options for backward compatibility.

Configure ORS Request Attempts

In a circular ORS load balancing strategy, max_ors_request_attempts provides you with the ability to select the next ORS Server in the list of ORS Servers defined for the service when the request to the first ORS fails.

For example, if you set the value of max_ors_request_attempts to 1, the first ORS Server in the list will be used only one time, and in case of ORS failure, the request will fail. If you set the value to 3, the first ORS Server in the list will be used and if the request fails, the next ORS Server in the list will be used, and so on, until the third server. After the third server fails to respond, the request returns a failure. A linear ORS load balancing strategy follows the same process with the max_ors_request_attempts option for retry on failure.

Advanced Setup Scenarios for ORS Connections

For any advanced setup, the default ORS Load Balancing strategy is circular and enabled by default.

Important

Unless you have specific needs, using the Connections tab to add GMS connections to ORS should cover most use cases.

Overwrite General Server Settings

To define a list of ORS servers at the GMS application level, you can set a list of ORS URLs in the server section by using the _ors option.

• Include all of the ORS URLs in the _ors comma-separated list, regardless if they are backup or primary servers.
• To modify the strategy mechanism related to this list, edit the _ors_lb_strategy option of the server section.
• This configuration applies to the application's services by default.

Overwrite Settings per Service

Important

Your service must be of type ors.

To overwrite ORS settings at the service level, you can use the Service Management User Interface to set a comma-separated list of ORS URLs in the _ors option of your service.

• For each service, you can also specify a load balancing strategy in the _ors_lb_strategy option. This ensures the possibility to define as many load balancing strategies as services with a distinct list of Orchestration Servers.
• By default, the load balancing strategy is circular.

How to Manage ORS Settings in a Cluster

If you define an application cluster for your GMS applications and if you wish to have specific ORS settings, you can edit your service configuration through Configuration Manager, Genesys Administrator, or Genesys Administrator Extension instead of using the Service Management User Interface.

• If you define your load balancing properties for your service in this cluster configuration, these service options apply to all of the GMS nodes.
• If you modify these service options in one of the GMS nodes, the new options apply to this given node and cluster options are superseded in this node.

This mechanism lets you define common service options for your cluster, with the possibility to fine-tune the service options in one or more GMS nodes.

1. Open your application's configuration and select the Options tab. Edit your service.<service_name> section.
2. Click Create New Section/Option.
3. Enter _ors for the Option Name, and then enter the list of URLs, separated with commas, for the Option Value. Click OK.
4. (Optional) Click Create New Section/Option again. Enter _ors_lb_strategy for the Name, and then enter circular or linear for the Value. If not specified, the default _ors_lb_strategy value is circular.

Section	Option	Default	Description
service.<service name>	_ors	empty	Comma-separated list of ORS URLs. http://host1:port1,http://host2:port2, Overrides the _ors option of the server section.
service.<service name>	_ors_lb_strategy	circular	Strategy for the ORS load balancer. This option overrides the _ors_lb_strategy option of the server section. Supported values are: circular or linear.