Table of Contents
This chapter introduces the components of an OpenFrame migration: resource migration, application migration, and database migration.
There are two methods for modernizing a mainframe system to an open system.
While the Big Bang method requires a lot of time and manpower, the rehosting method lowers costs because the rehosting solution converts the application system into an open system.
To use a mainframe application system in OpenFrame, the user resources from the mainframe must be migrated to OpenFrame. This resource migration process is called OpenFrame migration.
The OpenFrame migration process consists of four types of migration, and the following sections describe each type in detail.
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Resource migration
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Data set migration
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Application migration
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Database migration
Although migration is classified into the previous four types, related applications, resources, data sets and databases are migrated together in an actual migration project.
The following shows the migration process.
During resource migration, user resources such as JCL and CSD are converted for use in OpenFrame. The first step in this process is to extract the original EBCDIC data from mainframe.
The following shows the general resource migration process.
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Convert EBCDIC resources to ASCII resources.
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Import the resources into OpenFrame.
"Resources" are a wide range of system resources used in mainframe and OpenFrame systems, including data sets, CICS resources, JCL. This guide classifies system resources into three categories: data sets, application resources, and other system resources. Each categories are covered in "Chapter 2: Resource Migration", "Chapter 3: Data Set Migration" and "Chapter 4: Application Migration".
Data set migration converts mainframe data sets into a format supported by OpenFrame. This process requires EBCDIC data extracted from the mainframe.
The following shows the general data set migration process.
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Convert resource files that contain the data set schema from EBCDIC to ASCII.
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Extract data set schema from the ASCII resource file.
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Convert and import the EBCDIC data set into OpenFrame.
Application migration converts mainframe CICS, IMS and batch application programs into a format supported by OpenFrame. This process requires the EBCDIC source extracted from the mainframe.
The following shows the general application migration process.
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Convert application code from EBCDIC to ASCII.
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Compile ASCII application code to generate an application binary.
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Deploy the binary to OpenFrame.
Since the database migration process depends on the target DBMS that will be used in OpenFrame, with varied tools and methods according to the database type, it is not covered in this guide.
Note
For more information about migrating databases from mainframe to OpenFrame, refer to the respective database supplier's manual.
An OpenFrame migration project involves the pre-analysis and migration steps.
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Pre-analysis
Pre-analysis is performed by an experienced consultant.
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Migration
Migration involves the use of different OpenFrame conversion tools depending on the resource to move from the legacy system to an OpenFrame system. This guide describes the main conversion methods and tools.