There are many decisions that organizations must make when deciding how to provide business-critical applications to remote employees effectively and efficiently. This includes the technical architecture of the solution chosen to deliver these applications to end-users and business stakeholders.
There are myriads of remote solutions available that provide a vehicle for businesses to deliver their applications. There are generally two types of session technologies that allow providing sessions to remote end-users – single-session and multi-session. 
Let’s take a look at single-session vs multi-session and examine the similarities and differences as well as the pros and cons of the solutions to determine which is best for delivering cost-effective remote applications for your organization.
What is a Session?
Before diving off into the weeds of single-session and multi-session, we first want to define what a session is exactly. This will help to put context around the single-session and multi-session environments. So, what exactly is a session, especially when we think about remote end-users?
The term session can exist in many different contexts as part of networking, general information technology, and application development. The session layer is part of the OSI layer of networking, residing just above the transport layer and just below the presentation layer. However, rather than just referring to a rudimentary networking term as part of the OSI network model, a session – when in the context of application delivery – refers to more than that.
In terms of virtual application delivery – a session refers to the period of time that an end-user launches, interacts with, and then closes an application.
What is a Single-Session?
Let’s first take a closer look at the single-session approach when looking at application delivery. This is also referred to as single-user session. The single-session architecture is the older and more traditional architecture of the two. In basic terms, a single-session application means that a single instance of an application is loaded and this single instance is meant to interact with a single user.
Traditional applications must be written to interact with users in a multi-session way. As an example, even if a single user wants to interact with more than one instance of a single-session application, this generally requires two different instances of the software to run to allow the user to interact with more than one instance of the software.
What is Multi-Session?
A multi-session or multi-user session supports more than one user interacting with an application at the same time. Many users may be able to use the same application process simultaneously. Of course, with this being the case, the application needs to be written in such a way to support multiple users.
Single-Session vs Multi-Session Remote Application Delivery
With the current shift from a majority of people working on-premises to a majority of people working in a remote-work layout, and no end in sight to the new paradigm, organizations have had to choose and deploy remote work solutions to enable remote employees to remain productive. There are a number of different types of solutions that provide remote access. These solutions can either be based on the single-session or multi-session architecture to deliver applications.
What are the differences in how the single-session and multi-session work in the context of remote access and remote applications for remote employees? First, let’s take a closer look at single-session remote work technologies for application delivery and how these are defined as such.
As an example, VMware Horizon View is primarily used as a single-session delivery of applications. While VMware Horizon can broker multiple sessions from many different users to the assigned resources, in a VMware Horizon environment, one desktop and the associated applications on that desktop are generally assigned to a single user. Additionally, since Horizon environments typically target Windows client operating systems, these only allow single sessions to be active to a single desktop at a time.
Below is a simplified overview of this type of user session architecture.
Single-Session Remote Application Delivery Architecture Overview
Additional examples of single-session application delivery include the likes of:
- Nutanix Xi Frame – a cloud-native and browser native Desktop-as-a-Service solution that delivers virtual apps and desktops to users.
- Amazon AWS AppStream – a fully-managed application streaming service that allows centralized management and streaming of desktop applications to users.
What are the benefits and considerations when using single-session application delivery?
Benefits
- Applications and desktops are run securely in your data center
- They generally provide a good application experience
- Due to the single-session delivery, users can be assigned to a single machine that can be customized for a particular user
Considerations
- This type of application delivery can increase the amount of server resources needed for end-user environments
- Single-sessions technologies are generally less efficient than multi-session application delivery technologies
- Not as cost-effective as multi-session application delivery due to the resource requirements at scale
Let’s compare single-session solutions to multi-session application delivery technologies. Multi-session application delivery generally uses multi-session operating systems to deliver virtual applications and desktops published to end-users. One example of this type of application delivery is Cameyo’s digital workspace platform, which enables organizations to deliver any Windows or internal web applications to any device, from the browser, without the need for VPNs.
With multi-session architecture, organizations can place more focus on the applications presented to end-users and enable delivering these over lightweight browser sessions. While there may be some need for full desktop sessions for certain power users including graphics designers, engineers, or other CAD/CAM users, most users simply need to run business applications, in which case full virtual desktop environments are overkill.
Publishing applications using multi-session architecture provides much more efficient use of infrastructure since unnecessary resources do not have to be provisioned to provide an entire end-user desktop in most cases. This leads to scalability benefits and cost savings as a result.
Aside from Cameyo, additional examples of this type of application delivery include:
- Citrix Virtual Apps & Desktops – Enables the publishing of apps and desktops to end-users
- Remote Desktop Session Hosts – Using Windows Server infrastructure, remote desktop sessions can be presented to end-users
Below is a simplified overview of multi-session architecture. As shown, a single application server can provide the resources needed for multiple users.
Multi-Session Architecture Provides an Efficient, Scalable, and Cost-Effective Approach
What are the benefits and considerations of multi-session architecture?
Benefits
- Provides the most cost-effective application delivery solution
- Provides high-density users to hardware ratio
- Extremely scalable
- Requires a multi-session operating system
- Applications can be published and delivered in a web browser for easy access
- High-quality user experience
- Data and applications are centrally managed
- Provides data security and consistency to end-users
Choosing Between Single-Session and Multi-Session Architectures
There are many different solutions to choose from when it comes to delivering digital workspaces today and different businesses have different needs to deliver their business-critical applications. However, all businesses generally share the requirement to operate with cost-efficiency and cost-predictability.
These are areas where multi-session technologies shine when delivering digital workspaces and business-critical applications to remote end-users. To recap the benefits of multi-user solutions:
- Multi-session solutions focus on applications
- Organizations delivering multi-session applications no longer need to provide full desktops in most cases
- Virtualizing applications and not desktops leads to fewer resource requirements
- Fewer resource requirements lead to lower costs
- Higher densities mean that organizations can scale more easily
- This also means that costs are easier to predict in the long term
Single-user sessions are better suited for a few corner cases where full end-userend user desktops may be needed for a few power users who may benefit from full, persistent, customized desktops that may have very large graphics requirements.
To recap the benefits with single-session environments:
- Single-sessions allow providing full desktop environments to end-usersend users
- Application streaming technologies can also be single-session based such as AWS AppStream
- Single-session technologies are well-suited for power users requiring full, persistent desktops
- As new advancements are made in VDI and other technologies, single-session is becoming more efficient
Wrapping Up
Determing the right approach to application delivery requires considering the needs of your business and understanding the various types of technologies and solutions that make application delivery possible. Single-session and multi-session architectures are at the heart of the various solutions on the market today.
Understanding the pros and cons of each type of solution in relation of your business needs can help to choose the right technology for application delivery. In general, multi-session technologies provide many advantages over single-session solutions from an efficiency and cost standpoint.
Businesses today are generally application-focused. Multi-session virtual app delivery provides a great way to efficiently virtualize and deliver applications, effectively and efficiently with only a web browser. Multi-session virtual app delivery can help to transform your business using modern tooling and cloud-native technologies.