Product Documentation

Using StyleBooks to Configure GLB

You can use the Multi-cloud GLB StyleBook to configure GLB configurations on Citrix ADC instances that are provisioned in your data centers. Make sure that you have configured the site IP address on the Citrix ADC GLB instance in each data center.

You can also use this StyleBook to create a parent site that accepts child sites that you might add later in the GLB nodes. To configure multi-cloud GLB configuration on Citrix ADC instances.

  1. Navigate to Applications > Configuration, and click Create New.

  2. The Choose StyleBook page displays all the StyleBooks available for your use in the Citrix Application Delivery Management (ADM). Scroll down and select Multi-cloud GLB StyleBook.

    The Multi-cloud GLB StyleBook is used to configure GLB for an application that is deployed in multiple clouds and on-premises sites. The StyleBook appears as a user interface page on which you can enter the values for all the parameters defined in this StyleBook.

    Note: The terms data center and sites are used interchangeably in this document.

  3. Set the following parameters:

    • Application Name. Enter the name of the application deployed on the GLB sites.
    • GLB Algorithm. Choose the global load balancing algorithm (method) for selecting the site that serves a client.  The options that are available in the drop-down list box are LEASTCONNECTION, LEASTBANDWIDTH, LEASTPACKETS, ROUNDROBIN, STATICPROXIMITY, SOURCEIPHASH, and RTT.
    • Geo Database File. If you selected STATICPROXIMITY as the GLB algorithm, enter the complete path and name of the database file that contains the static proximity data. Make sure the database file is present on all GLB Citrix ADC instances at the specified location. Alternatively, you can retain the default file.
    • Protocol. Select the application protocol of the deployed application from the drop-down list box.
    • Persistence Settings. Persistence configured on a virtual server maintains the states of connections on the servers represented by that virtual server (for example, connections used in e-commerce).  Persistence overrides the load balancing methods once the virtual server is selected. If persistence configuration is applied to a service that is DOWN, the instance uses the load balancing methods to select a new service, and the new service becomes persistent for subsequent requests from the client.
    • Persistence Type. Select the persistence type to use for this application. For example, if you select persistence as SOURCEIP, after the initial selection of the site hosting the application, all subsequent requests from the same client are sent to that site for access to the application’s services.
    • Persistence Timeout. If you selected SOURCEIP as the persistence type, enter the number of minutes before the persistence session expires after the last client request. The range is from 2 to 1440 minutes. The minutes are resolved in seconds.
  4. Spillover Settings. Configure the spillover feature to forward the spillover connections to a secondary or backup virtual server when, for example, the connection limit or bandwidth limit of the primary virtual server has reached the threshold value.

    • Spillover Method. From the drop-down list box, select the method of spillover. For example, CONNECTION spillover method monitors the number of connections that are active on the primary server. If the spillover threshold is reached for this method, new connections are diverted to the first available virtual server in the backup chain. The HEALTH spillover method allows you to spillover if the threshold drops below a configured threshold. For example, less than 70%.

      Note: Except HEALTH spillover method, other methods are applicable only when Citrix ADC is used as load balancer instance.

    • Spillover Threshold. Enter a threshold value for the spillover method that you have selected.

    • Spillover Persistence.  Enable Spillover Persistence if you want the backup virtual server to continue to process the requests it receives, even after the load on the primary falls below the threshold.

    • Spillover Persistence Timeout. Configure the time period for which Spillover persistence is in effect. The minimum value is 2 minutes and the maximum value is 1440 minutes. The minutes are resolved in seconds.

  5. Persistence/Spillover Persistence ID. If you have selected SOURCEIP as persistence type or if Spillover persistence is enabled, enter a unique number to identify the same domain on all the GLB appliances. The range is from 1 to 65535.

    • Health Check of GLB service end points (Optional)
    • Health Check Type. From the drop-down list box, select the type of probe used for checking the health of the load balancer VIP address that represents the application on a site.
    • Secure Mode. (Optional) Select Yes to enable this parameter if SSL based health checks are required.
    • HTTP Request. (Optional) If you selected HTTP as the health-check type, enter the full HTTP request used to probe the VIP address.
    • List of HTTP Status Response Codes. (Optional) If you selected HTTP as the health check type, enter the list of HTTP status codes expected in responses to HTTP requests when the VIP is healthy.
  6. GLB Domain Names. This section allows you to configure the list of DNS domain names associated with this application. Click the plus icon (+) to create a DNS domain name for the application.

  7. GLB Sites. This section allows you to configure the list of sites on which this application is deployed.

    The GLB site is the top-level entity for the GLB communications. The information specified when configuring the site is used for linking local sites to remote sites and sharing monitoring data by using the Citrix Metrics Exchange Protocol (MEP). The IP address is owned by the GLB Citrix ADC instance and uses TCP port 3009. The GLB Sites section in the StyleBook allows you to specify as many GLB sites as needed.

    Click the plus icon (+) to add sites.

    • Site Name. Enter the name of the site.
    • Site IP Address. Enter the IP address that the site uses as its source IP address when exchanging metrics with other sites. This IP address is assumed to be already configured on the GLB instance in each site.
    • Site Public IP Address. (Optional) Enter the Public IP address of the site that is used to exchange metrics, if that site’s IP address is NAT’ed.
  8. Child Sites. Click the plus icon (+) to configure the required child sites.

    • Child Site name. Enter the name of the site.
    • Child Site IP Address. Enter the IP address of the child site. Here, use the private IP address or SNIP of the Citrix ADC node that is being configured as a child site.
    • Site Public IP Address. (Optional) Enter the Public IP address of the site that is used to exchange metrics, if that site’s IP address is NAT’ed.
  9. Services Site Persistence. Select the type of persistence used from the drop-down list box to be used for the GLB services on the site.

    • Select ConnectionProxy to allow the site to create a connection to the GLB site that inserted the site cookie, proxy the client request to the original site, receive a response from the original GLB site, relay the response back to the client, and close the connection.
    • Select HTTPRedirect to allow the site to redirect the request to the site that originally inserted the cookie. For more information on persistence, see Configuring Persistent Connections.
  10. Active GLB Services: This section allows you to configure the list of active services on the sites where the application is deployed.

    Service IP. Enter the IP address of the GLB service on this site.

    • Service Public IP Address. If the virtual IP address is private and has a public IP address NAT’ed to it, specify the public IP address.
    • Service Port. Enter the port of the GLB service on this site.
    • Service Weight. Enter the weight that is assigned to the GLB service.

      Note: You can assign relative weights to the services, depending on the percentage of traffic that needs to be sent to the cloud and the percentage of traffic that must be handled on premises. For example, if you have assigned a weight of 3 to the cloud-based GLB service and 7 to the on-premises GLB service, 30% of the traffic is directed to the cloud and 70% is handled on premises.

    • Site Name. Enter the name of the site on which the GLB service is located.
    • Site Prefix. Enter a prefix for the site on which the GLB service is configured. This is applicable when site persistence is enabled and the method is httpredirect. The site prefix value must be unique across all the GLB services of an application.
    • Max Client Connections. Enter the maximum client connections that are configured in the GLB service, if you have selected DYNAMICCONNECTION as a spillover method in Spillover Persistence settings. If you do not provide a value, by default the system assigns a number to the maximum client connections that can be configured.
  11. Passive GLB Services: This section allows you to configure the list of passive services on the sites where the application is deployed with an active-passive topology. Provide information for all the backup GLB services similar to the information that you provided for active GLB services.

  12. Click Target Instances and select the Citrix ADC instances configured as GLB instances on each site on which to deploy the GLB configuration.

  13. Click Create to create the GLB configuration on the selected Citrix ADC instances. You can also click Dry Run to check the objects that would be created in the target instances. The StyleBook configuration (configpack) that you have created appears in the list of configurations on the Configurations page. You can examine, update, or remove this configuration (configpack) by using the Citrix ADM GUI.

Using StyleBooks to Configure GLB

In this article