Migrate IBM mainframe applications to Azure with TmaxSoft OpenFrame

Azure Bastion
Azure ExpressRoute
Azure Files
Azure SQL Database
Azure Virtual Machines

Solution ideas

This article describes a solution idea. Your cloud architect can use this guidance to help visualize the major components for a typical implementation of this architecture. Use this article as a starting point to design a well-architected solution that aligns with your workload's specific requirements.

Lift and shift, also known as rehosting, is the process of mainframe migration to produce an exact copy of an application, workload, and all associated data from one environment to another. Mainframe applications can be migrated from on-premises to public or private cloud.

TmaxSoft OpenFrame is a rehosting solution that makes it easy to lift-and-shift existing IBM zSeries mainframe applications to Microsoft Azure, using a no-code approach. TmaxSoft quickly migrates an existing application, as is, to a zSeries mainframe emulation environment on Azure.

This article illustrates how the TmaxSoft OpenFrame solution runs on Azure. The approach consists of two virtual machines (VMs) running Linux in an active-active configuration. An Azure Load Balancer distributes incoming traffic between the VMs. OpenFrame emulation software runs on the VMs and provides a zSeries runtime and facilities. Working with the OpenFrame software is an Azure SQL Database. This modernized database layer includes built-in business continuity features.

Potential use cases

Many scenarios can benefit from TmaxSoft OpenFrame lift and shift. Possibilities include the following cases:

  • Businesses seeking to modernize infrastructure and escape the high costs, limitations, and rigidity associated with mainframes.
  • Organizations opting to move IBM zSeries mainframe workloads to the cloud without the side effects of a complete redevelopment.
  • IBM zSeries mainframe customers who need to migrate mission-critical applications while maintaining continuity with other on-premises applications.
  • Teams looking for the horizontal and vertical scalability that Azure offers.
  • Businesses that favor solutions offering disaster recovery options.


The following diagram shows the patient record creation request flow:

Architecture diagram showing a lift and shift implementation that migrates IBM zSeries mainframes to Azure.

Download a Visio file of this architecture.

At the center of the diagram are two virtual machines. Labeled boxes indicate that TmaxSoft OpenFrame software runs on the machines, and each box represents a different type of software. These programs migrate applications to Azure and handle transaction processes. They also manage batch programs and provide security. A load balancer is pictured above the virtual machines. Arrows show that it distributes incoming traffic between the machines. Below the virtual machines, a file sharing system is pictured, and to the right is a database. From arrows, it's clear that the virtual machines communicate with the file share and the database. A dotted line surrounds all these components. Outside that line are on-premises users, Azure users, and disaster recovery services. Arrows show the users interacting with the system. :::image-end:::

  1. On-premises users interact with OpenFrame applications by using 3270 WebTerminal, OFManager, and OFStudio:

  2. Azure ExpressRoute creates private connections between the on-premises infrastructure and Azure. Transport Layer Security (TLS) connections that use port 443 provide access to web-based applications:

    • After migration, the web application presentation layer remains virtually unchanged. As a result, end users require minimal retraining. Alternatively, the web application presentation layer can be updated to align with UX goals.
    • Azure Bastion hosts work to maximize security. While giving administrators access to VMs, these hosts minimize the number of open ports.
    • OpenFrame provides middleware integration. For instance, this functionality works with web services and message queues (MQs).
  3. The TmaxSoft solution uses two VMs. Each one runs an application server, and an Azure Load Balancer manages approaching traffic. OpenFrame supports both active-active and active-passive configurations.

  4. OpenFrame language compilers migrate COBOL, Assembler, PL/I, Easytrieve, and other mainframe applications to Azure by recompiling the source.

  5. OpenFrame Online provides tools and commands that replace CICS, IMS-DC, Application Development and Maintenance (ADM), and Application Infrastructure and Middleware (AIM) technologies.

  6. OpenFrame Batch provides tools for managing batch programs that replace the job entry subsystem (JES). OpenFrame Batch minimizes code updates by supporting native Job Control Language (JCL) syntax and batch utilities.

  7. Tmax Access Control Facility (TACF) Security provides authentication and authorization features in OpenFrame by extracting and migrating mainframe security rules.

  8. UnixODBC (Open Database Connectivity) connection drivers communicate with relational database management systems (RDBMSs). Examples include Azure SQL Database, Microsoft SQL Server, Oracle, Db2 LUW, Tibero, Postgres, and MySQL.

  9. Azure File Share is mounted on the Linux server VMs. As a result, COBOL programs have easy access to the Azure Files repository for file processing. Load modules and various log files also use Azure File Share.

  10. OpenFrame can integrate with any RDBMS. Examples include Azure SQL Database, SQL Server, Oracle, Db2 LUW, Tibero, Postgres, and MySQL. OpenFrame uses ODBC connection drivers to communicate with installed databases.

  11. Azure Site Recovery provides disaster recovery (DR) for the virtual machine components.


  • Azure ExpressRoute extends on-premises networks into the Microsoft cloud by using a connectivity provider. ExpressRoute establishes private connections to Microsoft cloud services like Microsoft Azure and Microsoft 365.

  • Azure Bastion provides secure and seamless Remote Desktop Protocol (RDP) and Secure Shell (SSH) connectivity to VMs in a network. Instead of using a public IP address, users connect to the VMs directly from the Azure portal.

  • Azure Load Balancer operates at layer four of the Open Systems Interconnection (OSI) model. As the single point of contact for clients, Load Balancer distributes inbound traffic to back-end pool instances. It directs traffic according to configured load-balancing rules and health probes. The back-end pool instances can be Azure VMs or instances in a virtual machine scale set.

  • Azure VMs are one of several types of on-demand, scalable computing resources that are available with Azure. An Azure VM provides the flexibility of virtualization. But it eliminates the maintenance demands of physical hardware. Azure VMs offer a choice of operating systems, including Windows and Linux.

  • Azure Virtual Networks are the fundamental building blocks for private networks in Azure. These networks provide a way for many types of Azure resources, such as Azure VMs, to securely communicate with each other, the internet, and on-premises networks. An Azure virtual network is like a traditional network operating in a data center. But an Azure virtual network also provides scalability, availability, isolation, and other benefits of Azure's infrastructure.

  • Azure Files Storage Accounts and Azure File Shares are fully managed file shares in the cloud. Azure file shares are accessible via the industry standard Server Message Block (SMB) protocol. They can be mounted concurrently by cloud or on-premises deployments. Windows, Linux, and macOS clients can access these file shares.

  • Azure SQL Database is an intelligent, scalable relational database service built for the cloud. With AI-powered, automated features, Azure SQL Database handles database management functions like upgrading, patching, backups, and monitoring.

  • Azure Site Recovery provides replication, failover, and recovery processes to help keep applications running during outages.

Next steps