IBM COBOL Migration and Rehosting Challenges
IBM dialect of COBOL sticks fairly closely to COBOL 74/85 Standards.
However, IBM COBOL applications often utilise IBM Libraries for data and screen access.
SoftwareMining Translation Toolkit supports the most widely elements of these libraries.
(SoftwareMining services will endeavour to provide support for the missing libraries when undertaking translation Services).
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IMS, IDMS and DL1 Migration
IMS is the IBMS's Hierarchical database. IDMS is the netwoked database.
DL1 is the Database Access API for
Migration of application involves translation of IMS database can be migrated to SQL.
The DL/1 Statements are translated to SQL Queries.
A set of SoftwareMining Libraries are provided to replace the DL1 libraries.
This approach helps to simplify the Translated program by hiding the SQL queries, and move into distributed architecture
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CICS to Java / CICS to C# Migration
CICS is a set of libraries for control of Transaction Processing. CICS provides libraries for reading and writing of records and posting screens.
CICS applications tend to adapt an event-driven architecture - where screens "sent" to and "received" from terminals.
this differs from typical COBOL application where screen communication is synchronous - and application pauses in midst
processing - waiting for the 'RETURN' key to be pressed. Thus CICS Applications tend to be easily re-architecture into JAVA or C#.
Where possible, SoftwareMining translates COBOL CICS programs to native Java or C# patterns. For example, reading/writing QUEUES (READQ and WRITEQ),
is implemented within a standard Queue processing patterns in the target language. Or, reading/writing FILES (EXEC CICS READ WRITE REWRITE) are converted to Object-Relational data access.
This approach helps to simplify the Translated program by hiding the SQL queries.
pseudo-conversational CICS to Java or C# code running on Application ServerCICS Online applications which have many concurrent users are usually designed in a pseudo-conversational architecture. This design reduces the processor and storage requirements. Such applications are ideal for migration to a Session based Java/C# code which implement similar technologies, and allow implementation of new application within a cloud based architecture.
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COBOL with Embedded SQL Modernization
Some COBOL program use DB2 instead of VSAM files. Access to DB2 is provided via DB2 SQL queries.
Migration of EMBEDDED SQL Programs involves the translation of DB2 SQL to ANSI, and
replacement of COBOL/EMBEDDED SQL Integration features with standard Java/C# practices.
SoftwareMining CORECT changes the Embedded SQL statements from COBOL to Java / C# dialects.
Additionally, the system allows externalization of SQL statements in order to ease future database migrations e.g from DB2 to Oracle.
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Migration of COBOL Stored Procedures to Java or C#
SoftwareMining tools can be used to migrate COBOL Stored Procedures to Java or C#.
The new Java or C# stored-procedures can then be imported into a variety of databases such as Oracle or Microsoft SQL Server.
Due to use of Object-Orientation, Exception handling, and framework based architecture, Java and C# stored procedures have better maintainability than standard Transact SQL or PL SQL scripts
The new stored procedures are run within the target database environment, leading a better performance.
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Migration of BMS Screens to XML
BMS is used for Screen Definitions in IBM CICS applications.
BMS Files contain an "ASCI" command set to define position of elements.
SoftwareMining translates the BMS Screens to XML/XSLT architecture which works with an Web-Server, to produce HTML screens at run-time.
Although in HTML, The translated BMS screens would still have a "green-screen" look and feel.
As a part of an application modernization project, many sites redesign the screens to benefit from a new look and feel.
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3270 Screens
The set of control characters required to display a screens on a Terminal is encoded in variables within the Programs.
The control characters are typically not human-legible, and their inclusion in
COBOL programs can make the application less maintainable.
SoftwareMining tools can translate the Control Characters to a more human readable XML , JSP or ASP files.
As a part of an application modernization project, many sites redesign the screens to benefit from a new look and feel.
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CICS DB2 Data Migration
IBM COBOL Applications typically access DB2 database via either Embedded SQL (EXEC ESQL) or CICS READ/WRITE APIs. Once SoftwareMining migrates the COBOL code to Java or C#, the new applications may access the same databases through JDBC or OLE.NET drivers. Migration from DB2 database to another Relational Databases such Oracle or SQL Server would require very few changes to the new Java or C# code: The Object-Relational-Model (ORM) classes would internally cater for database access, and the externalized ESQL statements can be modified "outside" the tested Java / C# code.
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IBM COBOL COBOL Migration, Modernization and Rehosting Project Phases
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The translation of to Java or C# applications involve
- Asset Management: Identify all the artifacts required for translation .
- (Optional) Business Rule Extraction.
- Translate to target language
- Database and Data Migratation
- Migrate JCL / WFL / CL
- Creation and Population of Test Database
- System acceptance testing
- System acceptance testing
- User Acceptance Testing
- (Client): Interation 2 Improvements: Screen Redesign, SOA Integration, Cloud Deployments, Coding Improvements and cleanup
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IBM COBOL Migration, Modernization and Re-hosting References
IBM
IBM CICS
Pseudo Conversational Transactions (Wiki)
Pseudo Conversational Transactions (IBM)
SoftwareMining on Wikipedia
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