Citrix Application Delivery Management service

Configuration

Citrix ADM manages all the Citrix ADC VPX clusters in Google Cloud. Citrix ADM accesses the Google Cloud resources using the Cloud Access Profile.

The following flow diagram explains the steps involved in creating and configuring an Autoscale group:

Autoscale ADC instances workflow

Prerequisites

This section describes the prerequisites that you must complete in Google Cloud and Citrix ADM before you Autoscale Citrix ADC VPX instances.

This document assumes you possess a Google Cloud account. For more information on how to create an account, see Google Cloud Documentation.

Set up Google Cloud components

Before provisioning Citrix ADC VPX instances in Citrix ADM, do the following tasks in Google Cloud:

  1. Enable APIs
  2. Create a Service Account
  3. Create a VPC network
  4. Create a firewall

Enable APIs

Citrix ADM requires programmatic access to deploy and provision the required resources in Google Cloud. So, enable the following APIs on your Google Cloud project:

For more information about how to enable APIs in Google Cloud, see Enabling APIs.

Create a Service Account

The ADM uses a Service Account to access your Google Cloud resources. Do the following to create a service account:

  1. Log in to your Google Cloud account.

  2. Go to IAM & Admin > Service Accounts.

  3. Click +CREATE SERVICE ACCOUNT.

    Create two service accounts, one service account is used for ADM. And, another is used for ADC instances. Do the following steps to create a service account.

    1. Specify the name, ID, and description and click Create.

    2. Assign the following predefined roles:

      • IAM roles required for ADM

         roles/iam.serviceAccountUser
         roles/compute.instanceAdmin.v1
         roles/compute.networkAdmin
         roles/dns.admin
        
      • IAM roles required for the ADC instances that are created by ADM:

         roles/compute.instanceAdmin.v1
         roles/compute.networkAdmin
        

      These roles allow your service account to access Google Cloud resources.

    3. Click Done.

After you create a service account, add a key to it.

  1. Select the service account to which you want to add a key.

  2. Select Add key > Create new key.

  3. Select JSON key type and click Create.

Create a VPC network

Create three subnets in your VPC network - one each for the management, client, and server connections. Select the custom option to create a subnet. Specify an address range for each of the subnets. Specify the region in which you want the subnet to reside.

  • Management: A subnet in your management VPC Network dedicated for management. Citrix ADC has to contact Google Cloud services and requires internet access.

  • Client: A subnet in your client VPC network dedicated for the client side. Typically, Citrix ADC receives client traffic for the application via a public subnet from the internet.

  • Server: A subnet where the application servers are provisioned. All your application servers are present in this subnet and receives application traffic from the Citrix ADC through this subnet. For more information on how to create a subnet in Google Cloud, see VPC network overview.

Create a firewall

The firewall has rules that control the inbound and outbound traffic in the Citrix ADC VPX instance. You can add as many rules as you want. To Autoscale Citrix ADC instances, you must create three firewalls:

  • Management: A firewall is dedicated for the management of Citrix ADC VPX. Citrix ADC has to contact Google Cloud services and requires internet access. Inbound rules are allowed on the following TCP and UDP ports.

    • TCP: 80, 22, 443, 3008–3011, 4001, 27000, 7279
    • UDP: 67, 123, 161, 500, 3003, 4500, 7000

    Configure Cloud NAT to allow internet access from this subnet. For more information, see Using Cloud NAT.

    Note

    Ensure that the firewall allows the Citrix ADM agent to be able to access the VPX.

  • Client: A firewall is dedicated for client-side communication of Citrix ADC VPX instances. Typically, inbound rules are allowed on the TCP ports 80 and 443. And, the 60000 port is required to monitor the health of ADC instances.

  • Server: A firewall is dedicated for server-side communication of Citrix ADC VPX. For more information on how to create a firewall in Google Cloud, see VPC firewall rules overview.

Set up Citrix ADM components

Before provisioning Citrix ADC VPX instances in Citrix ADM, do the following tasks in Citrix ADM:

  1. Create a site.

  2. Provision Citrix ADM agent on Google Cloud.

  3. Attach the site to a Citrix ADM service agent.

Create a site

Create a site in Citrix ADM and add the client VPC details associated with your Google Cloud.

  1. In Citrix ADM, navigate to Networks > Sites.

  2. Click Add.

  3. In the Select Cloud pane,

    1. Select Data Center as a Site type.

    2. Choose Google Cloud from the Type list.

    3. Check the Fetch regions from the Google Cloud check box.

      This option helps you to retrieve the existing regions information from your Google Cloud account.

    4. Click Next.

  4. In the Choose Region pane,

    1. In Cloud Access Profile, select the profile created for your Google Cloud account. If there are no profiles, create a profile.

    2. To create a cloud access profile, click Add.

    3. In Name, specify a name to identify your Google Cloud account in Citrix ADM.

    4. In Key of the Service Account, specify the Service Account JSON created in Google Cloud.

      Access the Google Cloud account from ADM

    5. Click Create.

      For more information, see Create a Service Account.

    6. In Regions, select the region that contains the VPC network containing Citrix ADC VPX instances that you want to manage.

    7. Specify a Site Name.

    8. Click Finish.

Provision Citrix ADM agent on Google Cloud

The Citrix ADM service agent works as an intermediary between the Citrix ADM and the discovered instances in the data center or on the cloud.

  1. Navigate to Networks > Agents.

  2. Click Provision.

  3. Select Google Cloud and click Next.

  4. In the Provision Parameters tab, specify the following:

    • Name - specify the Citrix ADM agent name.

    • Site - select the site you have created to provision an agent and ADC VPX instances.

    • Cloud Access Profile - select the cloud access profile from the list.

    • Zones - Select the zones in which you want to create the Autoscale groups. Depending on the cloud access profile that you have selected, the zones of that profile are populated.

    • Network- Select the VPC network where you want to create Autoscale groups.

    • Subnet - Select the management subnet to provision an agent.

    • Labels - Type the key-value pair for the Autoscale group labels. A tag consists of a case-sensitive key-value pair. These labels enable you to organize and identify the Autoscale groups easily. The labels are applied to both Google Cloud and Citrix ADM.

  5. Click Finish.

Alternatively, you can install the Citrix ADM agent from Google Cloud. For more information, see Installing a Citrix ADM agent on the Google Cloud.

Attach the site to a Citrix ADM service agent

  1. In Citrix ADM, navigate to Networks > Agents.

  2. Select the agent for which you want to attach a site.

  3. Click Attach Site.

  4. Select the site from the list that you want to attach.

  5. Click Save.

Step 1 - Initialize Autoscale configuration in Citrix ADM

  1. In Citrix ADM, navigate to Networks > AutoScale Groups.

  2. Click Add to create Autoscale groups.

    The Create AutoScale Group page appears.

  3. Select Google Cloud and click Next.

  4. In Basic Parameters, enter the following details:

    • Name: Type a name for the Autoscale group.

    • Site: Select the site that you have created to Autoscale the Citrix ADC VPX instances on Google Cloud. If you have not created a site, click Add to create a site.

    • Cloud Access Profile: Select the cloud access profile. You can also add or edit a Cloud Access Profile.

    • Citrix ADC Profile: Select the ADC profile from the list. Citrix ADM uses the device profile when it requires to log on to the Citrix ADC VPX instance.

    • Traffic Distribution Mode: Google Cloud supports only one traffic distribution, the Load Balancing using Google Network Load Balancer.

    • Enable AutoScale Group: Enable or disable the status of the ASG groups. This option is enabled, by default. If this option is disabled, autoscaling is not triggered.

    • Zone: Select the regions in which you want to create the Autoscale groups. Depending on the cloud access profile that you have selected, regions appear on the list.

    • Labels: Type the key-value pair for the Autoscale group labels. A tag consists of a case-sensitive key-value pair. These labels enable you to organize and identify the Autoscale groups easily. The labels are applied to both Google Cloud and Citrix ADM.

    Basic parameters Autoscale Google Cloud

  5. Click Next.

Step 2: Configure Autoscale parameters

In the AutoScale Parameters tab, enter the following details:

  1. Select one or more than one of the following threshold parameters whose values must be monitored to trigger a scale-out or a scale-in.

    • Enable CPU Usage Threshold: Monitor the metrics based on the CPU usage.

    • Enable Memory Usage Threshold: Monitor the metrics based on the memory usage.

    • Enable Throughput Threshold: Monitor the metrics based on the throughput.

      Note

      • Default minimum threshold limit is 30 and the maximum threshold limit is 70. However, you change to modify the limits.

      • Minimum threshold limit must be equal or less than half of the maximum threshold limit.

      • You can select more than one threshold parameters for monitoring. Scale-out is triggered if at least one of the threshold parameters is above the maximum threshold. However, a scale-in is triggered only if all the threshold parameters are operating below their normal thresholds.

    • Minimum Instances: Select the minimum number of instances that must be provisioned for this Autoscale group.

      The default minimum number of instances is equal to the number of zones selected. You can only increment the minimum instances in the multiples of the specified number of zones.

      For example, if the number of zones is 4, the minimum instances are 4 by default. You can increase the minimum instances by 8, 12, 16.

    • Maximum Instances: Select the maximum number of instances that must be provisioned for this Autoscale group.

      The maximum number of instances must be greater than or equal to the value of the minimum instances. The maximum number of instances cannot exceed the number of zones multiplied by 32.

      Maximum number of instances = number of zones * 32

    • Watch-Time (minutes): Select the watch-time duration. The time for which the scale parameter’s threshold has to stay breached for scaling to happen. If the threshold is breached on all the samples collected in this specified time then a scaling happens.

    • Cooldown period (minutes): Select the cooldown period. During scale-out, the cooldown period is the time for which evaluation of the statistics has to be stopped after a scale-out occurs. This period ensures the organic growing of instances of an Autoscale group. Before triggering the next scaling decision, it waits for the current traffic to stabilize and average out on the current set of instances.

    • Time to wait during Deprovision (minutes): Select the drain connection timeout period. During scale-in action, an instance is identified to de-provision. Citrix ADM restricts the identified instance from processing new connections until the specified time expires before de-provision. In this period, it allows existing connections to this instance to be drained out before it gets de-provisioned.

  2. Click Next.

Step 3 - Configure licenses

Citrix ADM provisions the ADC instances with the desired version & license. ADC images can either be customer licensed (BYOL) or licensed from Google Cloud.

Select one of the following modes to apply license to an ADC instance:

  • Allocate from Citrix ADM: The instance that you want to provision checks out the licenses from the Citrix ADM.

  • Allocate from Google Cloud: The Allocate from Cloud option uses the Citrix product licenses available in Google Cloud. The instance that you want to provision uses the licenses from the Google Cloud.

    If you choose to use licenses from Google Cloud, specify the product or license in the Provision Parameters tab.

For more information, see Licensing Requirements.

Allocate licenses from Citrix ADM

  1. In the License tab, select Allocate from ADM.

  2. In License Type, select one of the following options from the list:

    • Bandwidth Licenses: You can select one of the following options from the Bandwidth License Types list:

      • Pooled Capacity: Specify the capacity to allocate to an instance.

        From the common pool, the ADC instance checks out one instance license and only as much bandwidth is specified.

      • VPX Licenses: When a Citrix ADC VPX instance is provisioned, the instance checks out the license from the Citrix ADM.

    • Virtual CPU Licenses: The provisioned Citrix ADC VPX instance checks out licenses depending on the number of CPUs running in the instance.

    Note

    When the provisioned instances are removed or destroyed, the applied licenses return to the Citrix ADM license pool. These licenses can be reused to provision new instances.

  3. In License Edition, select the license edition. The ADM uses the specified edition to provision instances.

  4. Click Next.

Step 4: Configure provision parameters

  1. In the Provision Parameters tab, specify the following:

    • ADC Service Account: Select the service account that you have created in Google Cloud. The ADM uses a Service Account to access your Google Cloud resources.

    • Machine types: Select the required machine type from the list.

    • Image: Select the required Citrix ADC version image. Click Add New to add a Citrix ADC image.

    • Configuration Template – Select the configuration template that you want to use to deploy on the ADC instances.

    • IPs in Server Subnet per instance – Specify how many SNIP addresses each instance can have in the server subnet.

    Provision parameters for ADC instance

    In this tab, you can also specify and configure the required NICs. Each NIC contains a dedicated firewall and subnet.

    For more information, see Create a VPC network and Create a firewall.

    NICs for an ADC instance

  2. Click Finish.

Step 5: Configure an application for the Autoscale group

  1. In Citrix ADM, navigate to Networks > Autoscale Groups.

  2. Select the Autoscale group that you created and click Configure.

  3. In Configure Application, specify the following details:

    • Application Name - Specify the name of an application.

    • Access Type - You can use the ADM autoscaling solution to both external and internal applications. Select the required application access type.

    • FQDN Type - Select a mode of assigning domain and zone names.

      If you want to specify manually, select User-Defined. To automatically assign domain and zone names, select Auto-generated.

    • Domain Name - Specify the domain name of an application. This option is applicable only when you select User-Defined FQDN type.

    • Zone of the Domain - Select the zone name of an application from the list. This option is applicable only when you select User-Defined FQDN type.

      This domain and zone name redirects to the virtual servers in Google Cloud. For example, if you host an application in app.example.com, the app is the domain name and example.com is the zone name.

    • Protocol - Select the protocol type from the list. The configured application receives the traffic depending on the selected protocol type.

    • Port - Specify the port value. The specified port is used to establish a communication between the application and the Autoscale group.

    • Auto Redirect HTTP traffic to HTTPS - Select this option to receive secured traffic to the application. Specify the HTTP port that you want to redirect.

    • ADC Configuration mode - Select the mode how you want to configure the application. You can either select StyleBooks or ADC CLI commands.

    Configure ASG applications

    Note

    Change the access type of an application if you want to modify the following details in the future:

    • FQDN Type
    • Domain Name
    • Zone of the domain

Configure the application using StyleBooks

When you select StyleBooks to configure an application for the Autoscale group, do the following:

  1. Choose the required StyleBook that you want to deploy configurations for the selected Autoscale group.

    Example ASG StyleBooks

    If you want to import StyleBooks, click Import New StyleBook.

  2. Specify the values for all the parameters.

    The configuration parameters are pre-defined in the selected StyleBook.

  3. Check the Application Server Group Type CLOUD check box to specify the application servers available in the virtual machine scale set.

    1. In Application Server Fleet Name, specify the Autoscale setting name of your virtual machine scale set.

    2. Select the Application Server Protocol from the list.

    3. In Member Port, specify the port value of the application server.

      Note

      Ensure AutoDisable Graceful shutdown is set to No and the AutoDisable Delay field is blank.

    4. If you want to specify the advanced settings for your application servers, check the Advanced Application Server Settings check box. Then, specify the required values listed under Advanced Application Server Settings.

    configure the application for an Autoscale group cloud

  4. If you have standalone application servers in the virtual network, check the Application Server Group Type STATIC check box:

    1. Select the Application Server Protocol from the list.

    2. In Server IPs and Ports, click + to add an application server IP address, port, and weight, then click Create.

    configure the application for an Autoscale group static

  5. Click Create.

Modify the Autoscale groups configuration

You can modify an Autoscale group configuration or delete an Autoscale group. You can modify only the following Autoscale group parameters:

  • Maximum and minimum limits of the threshold parameters

  • Minimum and maximum instance values

  • Drain connection period value

  • Cooldown period value

  • Watch duration value

You can also delete the Autoscale groups after they are created.

When an Autoscale group is deleted, all the domains and IP addresses are deregistered from DNS and the cluster nodes are de-provisioned.