VMware Horizon is a family of desktop and application virtualization solutions designed to deliver end user computing services, from both on-premises data centers and from cloud providers such as Amazon Web Services (AWS). The following section will provide a high-level overview of the components in the Horizon family of products that we will cover in this book, which includes the following:

• VMware Horizon Connection Server, Security Server, and Unified Access Gateway
• VMware Horizon Help Desk Tool
• VMware Horizon Just-in-Time Management Platform (JMP)
• VMware Horizon Composer
• VMware Horizon Agent
• VMware Horizon Client
• VMware vSphere, including vCenter Server
• VMware App Volumes
• VMware User Environment Manager
• VMware Horizon PowerCLI

The following diagram shows where each component of a typical Horizon installation resides within the data center. The only components that are not shown but are discussed in this book are the VMware App Volumes servers and the Windows-based files servers used for hosting VMware User Environment Manager data. If they were to be shown, both of these components would be located on the internal network, along with the Horizon Connection Server, vCenter Server, virtual desktops, and Microsoft Windows Remote Desktop Session (RDS) servers.

VMware Horizon Connection Server is a software service that performs as the broker for Horizon client connections. In this role, it authenticates user connection requests, verifies the desktops or Microsoft Windows RDS Servers that the user is entitled to access, and then directs the connection to the appropriate resource. Horizon Connection Server is installed on a dedicated server that is required to be a member of an Active Directory (AD) domain that is trusted by all Horizon clients. Horizon Connection Server also hosts the Horizon Administrator console, an Adobe Flex-based web application that is used to manage the Horizon environment and perform tasks including the following:

• Deploying virtual desktops
• Creating desktop or Microsoft Windows RDS-based pools
• Controlling access to desktop pools
• Creating and managing Horizon Cloud Pods
• Examining Horizon system events

The Horizon Connection Server is one component that is required in every Horizon environment. Chapter 2, Implementing Horizon Connection Server, provides the information needed to install and configure a VMware Horizon Connection Server. Chapter 6, Implementing a Horizon Cloud Pod, provides information regarding the configuration of the Cloud Pod feature that is used to provide Horizon clients with access to desktops across multiple Horizon Pods, with each Pod representing a standalone installation of VMware Horizon. The following chapters provide information about the deployment of Horizon desktops and the management of desktop pools:

• Chapter 7, Creating Horizon Desktop Pools
• Chapter 8, Implementing Microsoft Remote Desktop Services Application and Desktop Pools
• Chapter 9, Performing Horizon Pool Maintenance

VMware Horizon Security Server is a custom instance of the Horizon Connection Server that is designed to be installed in a datacenter Demilitarized Zone (DMZ), in order to provide strong levels of authentication and secure access for Horizon clients connecting from outside the organization's private network. Multiple Security Servers may be installed to provide load balancing and high availability to these external clients.

The following diagram shows the placement of a Horizon Security Server or Unified Access Gateway (discussed next) within a DMZ:

Horizon Security Server is installed on top of a supported version of Microsoft Windows' Server using the same installation package used for Horizon Connection Servers. Horizon Security Server is only required if providing access to Horizon clients residing outside of the company network. Chapter 4, Implementing Horizon Security Server, provides the information needed to install and configure a VMware Horizon Security Server.

VMware Horizon Unified Access Gateway, previously known as Horizon Access Point and first introduced in VMware Horizon 6.2, is designed to provide strong authentication, and secure access, for Horizon clients connecting from outside the organization's private network. The diagram in the previous section shows the placement of a Horizon Unified Access Gateway within a DMZ environment, as is typical since it performs similar functions to Horizon Security Server.

Unified Access Gateway is packaged in Open Virtualization Format (OVF) and is deployed on vSphere as a hardened, pre-configured Linux-based virtual appliance. Horizon Unified Access Gateway is provided as an option to Horizon Security Server and, like Security Server, it is only required if providing access for external clients. it is designed to be installed in a DMZ, and multiple appliances may be installed to ensure high availability and load balancing. Chapter 5, Implementing Horizon Unified Access Gateway, provides the information needed to install and configure a VMware Horizon Unified Access Gateway.

The VMware Horizon Enrollment Server was first introduced in version 7, is installed as a standalone service, and integrates with the VMware Workspace ONE Identity Manager to enable true Single Sign-On (SSO) for Horizon clients that are using non-AD-based authentication methods such as RSA SecureID. SSO means that, when using non-AD-based authentication methods, users will only need to log into Horizon once to reach their desktop or streamed application. The VMware blog post Introducing True SSO (Single Sign-On) in VMware Horizon 7 (http://blogs.vmware.com/euc/2016/03/true-sso-single-sign-on-view-identity-manager-authenticate.html) provides an overview of this new Horizon feature.

This feature is only used when Horizon clients use non-AD-based methods for authentication. Implementing solutions, such as SecureID and the VMware Workspace ONE Identity Manager, is outside of our scope. Therefore, the Enrollment Server will not be covered here, so consult the Horizon documentation (https://docs.vmware.com/en/VMware-Horizon-7/index.html) for additional information about the deployment and configuration of the Horizon Enrollment Server.

VMware vSphere, also referred to as ESXi or even ESX for earlier versions, is a Type 1 hypervisor that is the virtualization platform used for the vSphere suite of products. Type 1 hypervisors are designed to run directly on the host hardware, whereas Type 2 hypervisors run within a conventional OS environment.

ESXi is the only hypervisor that is fully supported by VMware for hosting Horizon virtual desktops, as it fully integrates with Horizon for full desktop life cycle management. All of the primary desktop provisioning and maintenance tasks are performed using the Horizon Administrator console; the vSphere Client is not used. Horizon supports multiple versions of vSphere, but vSphere 6.0 Update 1 and newer are required to leverage many of the latest features of the platform. vSphere 6.0 Update 2 or newer is required to use the latest version of Virtual SAN (vSAN). Refer to the VMware vCenter Server requirements section for examples of some Horizon features that require a specific version of both vSphere and vCenter Server.

VMware vSphere also includes the vSAN feature that uses local ESXi server storage to build a highly resilient virtual Storage Area Network (SAN) to provide storage for virtual machines. The deployment and configuration of vSAN are outside of our scope, so consult the Horizon documentation (https://docs.vmware.com/en/VMware-Horizon-7/index.html) if you require information about using vSAN with Horizon.

VMware vCenter Server is a software service that provides a central administration point for VMware ESXi servers, as well as other components of the vSphere suite. vCenter Server performs the actual creation and management of virtual desktops, based on instructions received from the Horizon Connection Server and the Horizon Composer Server.

VMware Horizon Composer is a software service that works alongside the VMware vCenter and Horizon Connection Servers to deploy and manage linked clone desktops. Horizon Composer can be installed directly on the vCenter Server, or on a dedicated server.

Horizon Composer is only required if linked clone desktops will be deployed. Chapter 3, Implementing Horizon Composer, provides the information required to install and configure Horizon Composer.

VMware Horizon Agent is a software service that is installed on the systems that will be managed by Horizon. This includes not only a virtual desktop image that will be deployed using Horizon, but also any physical desktops or Microsoft RDS Servers.

The Horizon agent provides services including, but not limited to, support for connecting the virtual desktop to Horizon's client-attached USB devices, client connection monitoring, virtual printing, and single sign-on.

VMware Horizon Client is a software application that is used to communicate with a Horizon Connection Server, and initiate connections to desktops and Microsoft Windows RDS servers.

The Horizon Client is available for multiple software platforms, including Microsoft Windows, Apple OSX and IOS, Android, and Linux. In addition, there are a number of Thin and Zero clients that come preloaded with Horizon-compatible clients.

VMware App Volumes is an optional component of VMware Horizon that provides multiple capabilities, particularly in environments where floating assignment desktops are used, or changes to a virtual desktop are discarded after every session (also known as non-persistent desktops). The deployment and configuration of VMware App Volumes are discussed in detail in Chapter 11, Implementing App Volumes.

The primary features of VMware App Volumes include the following:

• The ability for applications to be delivered to Horizon desktops or Microsoft Windows RDS servers, immediately and dynamically, in a manner that is transparent to the end user. This feature works both with Horizon desktops and Microsoft Windows RDS servers, and is called an App Volumes AppStack.
• The ability to roam user-installed applications across Horizon client sessions, even if a different desktop virtual machine is assigned during the next login. This feature is designed for use with Horizon desktops only, and is called Writable Volumes.

The following diagram shows the logical layering of multiple AppStack and a Writeable Volume on top of the host OS. Each of the items is attached to the host virtual machine individually when a user logs in, can be removed individually if changes are required, and will follow a user from one login to the next:

App Volumes AppStacks are packaged as a Virtual Machine Disk (VMDK) file and attached to one or more virtual machines as needed. The App Volumes agent seamlessly integrates this VMDK into the virtual machine's OS so no actual installation is performed. AppVolumes can even capture an application packaged using VMware ThinApp, which provides organizations who rely on ThinApp with an additional method for distributing its virtualized application packages.

App Volumes creates a unique Writeable Volume for each user, using a VMDK that is also seamlessly integrated into their current virtual machine. The Writable Volumes is attached to the Horizon desktop when the user logs in, and detached when the user logs off.

The combination of VMware App Volumes and VMware User Environment Manager (discussed next), provides organizations with a way to leverage the efficiencies of floating assignment non-persistent desktops (described in Chapter 7, Creating Horizon Desktop Pools), while still providing users with a highly personalized desktop experience.

VMware User Environment Manager (UEM) is an optional component of VMware Horizon that provides the ability to roam end user Windows profile and persona configuration data, including application settings, across different Windows Operating System (OS) versions, or even between physical desktops and virtual desktops or Windows RDS Servers.

VMware UEM works with all three Microsoft Windows profile types, including mandatory, roaming, or local. UEM is not a replacement for any of these profile types as it does not roam user data across sessions or devices, only across the profile and persona configuration. User data should be saved using techniques such as roaming profiles, or even folder redirection.

Highlights of the benefits of UEM include the following:

• A consistent and personalized end user experience, regardless of where a user logs in or which Windows OS they are using
• Implementation of various settings that previously required AD group policies, such as Windows user profile redirection, and some Horizon agent settings
• Customization of user settings, such as printers, based on logon location
• Elimination of the need to perform user profile migrations when moving to a newer version of Windows that has a new profile type (such as from Windows 8.1 to Windows 10)
• Robust design that scales to support over a hundred thousand end users
• Simple design that requires no scripting knowledge, can be implemented rapidly, and requires minimal infrastructure to begin using

Chapter 12, Implementing User Environment Manager, provides information regarding the implementation and administration of UEM.

VMware ThinApp is an application virtualization platform that integrates with Horizon to provide users with rapid access to new or upgraded applications without having to perform any changes to the virtual desktops. Applications that have been packaged with ThinApp are delivered as a single executable file that runs in complete isolation to both of the other ThinApp packaged applications, as well as applications that are installed on the desktop itself.

ThinApp provides Horizon customers with a number of powerful capabilities. Two popular scenarios where ThinApp can benefit an organization are as follows:

• It eliminates application conflicts that can occur when specific programs are installed together within the desktop image
• It virtualizes legacy applications to ensure that they will continue to function regardless of the underlying Windows OS

This book does not have a dedicated chapter concerning VMware ThinApp, so consult the VMware ThinApp documentation page for more details about how it is used (https://www.vmware.com/support/pubs/thinapp_pubs.html).