GCOS 8 : DBSP

The full palette of Oracle RDBMS features, tools and utilities available on GCOS 8 increase the flexibility of the information system by opening GCOS 8 applications to a market-standard RDBMS, thus facilitating data exchange between GCOS 8 and distributed applications and dedicated servers.

1 DBSP OVERVIEW

DBSP - DataBase Server Processing - is a database management service designed to enable GCOS 8 applications to access relational databases compliant with the major commercial standards. The first release of DBSP offers an Oracle interface. Queries from TP and batch applications executing on GCOS 8 are fulfilled by the target RDBMS, which executes on a dedicated processor called the DataBase Server System (DBSS). GCOS 8 sites can now take full advantage of the industry-leading relational database manager without disruption to existing databases or applications.

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GCOS 8 in an open data environment :

Access to Oracle databases from GCOS 8 facilitates data exchange and interaction between GCOS 8 and distributed applications and dedicated servers. DBSP is particularly well-suited to GCOS 8 environments that are part of heterogeneous information systems.

With DBSP, GCOS 8 applications can access and update Oracle databases the same way they access IDS/II and RFM/II databases or UFAS files. The fact that Oracle runs on a separate system is largely transparent to application developers, who can create DBSP programs in the familiar application-development environment of GCOS 8.

High performance for production environments :

High performance is ensured in DBSP by the high-speed link developed for the newest technology GCOS 8 input-output processors (IOSP). The direction established with the IOSP and DBSP will be extended and enhanced with the forthcoming Twin Architecture™.

The DBSS is an AIX-based system meeting precise specifications and qualified for integration into the GCOS 8 environment. The result is that DBSP users can expect the quality of service required in a production environment : performance, availability, integrity and robustness.

The use of AIX plus the distributed database support provided by the Oracle RDBMS makes it particularly easy to share data between GCOS 8 and other platforms that support Oracle (UNIX, NT, OS/390, etc.).

DBSP for e-Business :

By facilitating data exchange between the different platforms that make up the information system infrastructure, DBSP supports GCOS 8 cooperation and interoperability with other corporate servers. As an example, DBSP can be the ideal solution for an e-Business infrastructure.

2 DBSP KEY BENEFITS :

DBSP increases the flexibility and maintainability of the information system by making it possible to use an RDBMS that is common to many heterogeneous platforms.

DBSP opens up GCOS 8, both technically and functionally :

• GCOS 8 applications can access Oracle databases while coexisting with other applications that use data managed by IDS/II, RFM/II, and/or UFAS.
• A standard, uniform representation of data can be used within a company, by offering the same data organization across heterogeneous and/or distributed environments (UNIX, NT, OS/390, etc.).
• A greater flexibility in choosing an information system architecture is provided, in particular for the distribution of applications and data :
- Applications running on platforms with different operating systems can concurrently access the same data.
- GCOS 8 applications can interact with the services provided by widely used software packages such as ERP.

• GCOS 8 production data can be used to supply or refresh decision-making systems such as Data Warehouses and Data Marts.
• Evolution to an e-Business infrastructure that integrates new services with data and applications controlled by GCOS 8 is made easier.
• Consolidation of existing distributed Oracle data on the DBSS can be considered .

3 DBSP CHARACTERISTICS AND RELATED ADVANTAGES

Oracle : the market-standard relational engine to improve fluidity of information exchanges.
Use of a standard SQL-92 universal access language for TP and batch applications on GCOS 8 can :

• help to provide an overall view of the company's data
• stimulate dialogue between database administrators and engineers, between IT and functional experts
• facilitate the search for and acquisition of skills and expertise
• guarantee the openness and longevity of GCOS 8-based developments

DBSS : a system dedicated to data management to boost efficiency

• Improves the overall performance of the GCOS 8 system through the close coupling of GCOS 8 and AIX, benefiting strategic applications.
- Application logic executes on GCOS 8.
- Database management executes on a dedicated system, the DBSS, whose totally scaleable configuration (CP, memory, disks, etc.), will depend on user needs.
- Connection via a high-speed link ensures high performance.

• Allows consolidation of distributed data on the DBSS.
• Facilitates data sharing between applications based on different platforms.

Oracle for GCOS 8 without changes to Oracle or GCOS 8.

• Access to Oracle in its native environment, as if it were local :
- Transparent architecture : GCOS 8 programmers code Oracle SQL statements without worrying about the location of the Oracle database.
- New RDBMS versions will become available as Oracle evolves.
- Standard RDBMS tools are used for creating, administering and monitoring databases on the DBSS.

• Data sharing by applications based on separate platforms, possibly running with different operating systems :
- GCOS 8 applications can access Oracle data stored on remote servers.
- Applications running on other platforms that support Oracle (UNIX, NT, OS/390, GCOS 7,…)
can access data managed by the DBSS.

• An environment integrated perfectly with GCOS 8

The DBMS managed by DBSP can enjoy a problem-free existence alongside the other data organizations supported by GCOS 8 (IDS/II, RFM/II, UFAS) :
• New developments can use the storage capacity of the DBSS without necessitating any changes to existing configurations.
• Existing applications can evolve, integrating DBSS-based data as necessary.

4 DBSP Architecture and Components

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The DBSP product consists of :
The DBSS platform :

• The DBSS hardware
• The DBSS customization software :

AIX, which includes File Transfer Protocol (FTP) software DBSP prerequisite software, including MicroFocus COBOL and the C compiler for AIX

NOTES :

- The DBSP software is designed to be used only on a DBSS, not on a free-standing UNIX system that was not acquired as part of the DBSP product.
- To avoid problems with DBSP performance or compatibility issues with subsequent DBSP software releases, the DBSS should be dedicated to use as a Database Server for the associated GCOS 8 system. That is, the DBSS should run only the DBSS software and DBSP surrogate clients created by the site.

• The DBSS attachment to the GCOS 8 system :
- Hardware to establish the high-speed link between the GCOS 8 system and the DBSS,

• The DBSP CMA software set that is made up of 2 parts running on both GCOS 8 and DBSS/AIX systems :
- Bull DBSP software that operates on the DBSS to accept calls from GCOS 8, pass those calls on to the Oracle RDBMS, and return the responses to GCOS 8,
- Bull DBSP software that operates under GCOS 8 to interface with programs that need to access DBSS-resident databases.

5 DBSP Hardware Architecture

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Overview of DBSP Hardware Architecture

The link between the DPS 9000 (GCOS 8) system and the DBSS (UNIX) system is implemented in the form of a Link Control Board (LCB) and two SCSI channels.

• Each SCSI interface transfers messages in one direction : i.e., one SCSI channel handles messages from the DPS 9000 to the DBSS; the other channel handles messages from the DBSS to the DPS 9000.

• The maximum length of the SCSI interfaces is 25 meters. The length of the interface has no effect on the speed of the connection between the DPS 9000 and the DBSS.

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More Detailed View of DBSP Hardware Architecture

The LCB is attached to a DPS 9000 ICU (Integrated [I/O] Control Unit). The LCB includes all of the logic necessary to handle the data path between the ICU of the DPS 9000 and the SCSI channels.
From the perspective of GCOS 8, the DBSS is configured and accessed as if it were a set of disk devices.
The DPS 9000 Service Processor serves multiple functions in a DBSP configuration :

• Mainframe system initialization includes DBSP
• Power Up DBSS from Service Processor
• Alerts at Service Processor when Hardware / Software failures :
- LCB, SCSI, DBSS Hardware, DBSP Software
- All GCOS DBSP applications alerted on next I/O after Failure

• On failure - Logically disconnect and reconnect the DBSS from GCOS
• Alternative console for AIX on the Service Processor
• Customer Service interface to the DBSS

5.1 DPS 9000 / GCOS 8 System

A DPS 9000/GCOS 8 system used in a DBSP configuration must be a DPS 9000/700-2, a DPS 9000/TA or a DPS 9000/TA200.
For each DBSS to be connected to the GCOS 8 system, an Integrated I/O Control Unit (ICU) on the DPS 9000 must be configured with a High-Speed Link that consists of :

• one Link Control Board (LCB).
• two SCSI channels.
• supporting software in the DBSS.

The specific hardware components required for each High-Speed Link is based on the specific DPS 9000 model to which the High-Speed Link will be connected, and other variables such as the IOSC/IOSP/DBSS already installed configurations.

5.2 DBSS

The DBSS is an Escala-based system meeting precise specifications and qualified for integration into the GCOS 8 environment. The result is that DBSP users can expect the quality of service required in a production environment : performance, availability, integrity and robustness.
The DBSS used in a DBSP configuration must have the following characteristics. These characteristics are defined when you order a specific model of DBSP.
One of the supported DBSS models. Your Marketing Representative must be consulted about the available, up-to-date DBSS models at the moment of the installation.
In April 2000,The DBSS systems are made up of Escala T430 systems with one, two or four CPUs, known as Entry, Mid-range and High-range DBSS systems.

DBSS Minimum configurations Summary (January 2001)

Basic, Minimum Configurations	Entry Model	Mid Range	High Range
Number of CPU	1	2	4
Memory size	512 MB	1 GB	2 GB
Internal disk drives 9,1 MB (1"/10 KPM)	2	2	2
600 MB int 14-32X CD-ROM driver	1	1	1
12/24 GB Int. 4MM DAT tape drive	1	1	1
PCI ultra SCSI adapters	2	2	2
PCI Ethernet adapter 10/100 MB/s	1	1	1
Local console	No	No	No
Internal Modem	1	1	1
UNIX Gold Maintenance level	Yes	Yes	Yes
GCOS 8 Attachment Kit	Yes	Yes	Yes
Basic HW & SW Documentation	Yes	Yes	Yes
AIX Bonus Pack for Server	Yes	Yes	Yes
AIX Server Library	Yes	Yes	Yes
AIX License	Yes	Yes	Yes
C for AIX (1 user)	Yes	Yes	Yes
MF/Merant Cobol (1 user)	Yes	Yes	Yes
Netbios (1-10 users)	Yes	Yes	Yes

Each DBSS model, totally scaleable, includes the following standard components :

• AIX system console, which is used to manage some of the functions that run on the DBSS.
• A Service Link from the DBSS to the Service Processor of the DPS 9000, which allows the Service Processor to be used to initialize the DBSS and for certain types of error reporting from the DBSS.
• A modem for a remote support link.

AIX-formatted disks with sufficient capacity for the storage of AIX software, DBSP software, site-specific DBSP surrogate clients, Oracle software, and Oracle database(s). Three different types of disk configuration have been validated :

•Internal drives
•DAS5300 subsystems
•EMC drives, sharable with GCOS 8, using the GCOS 8/UNIX sharing option

6 DBSP Software Architecture

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6.1 DBSP Program Architecture

In DBSP, each program is separated into two parts :

• The business logic, which executes on GCOS 8 as either :
a Transaction Processing Routine (TPR), or a batch workstation.
• SQL statements, which execute on the DBSS. These SQL statements access the database to retrieve and update data as directed by the business logic.

The figure below illustrates the structure of programs that access DBSS-resident databases.


SQL interface Procedures	Surrogate Clients, made up of : * = SCDP (surrogate Client Data Procedures) # = SQL Statements

• SQL statements, which execute on the DBSS. These SQL statements access the database to retrieve and update data as directed by the business logic.

Each set of SQL statements, labeled "#" in previous figure, is linked with a copy of the Surrogate Client Data Procedures (SCDP), labeled "*" in the figure. The combination of SQL statements and SCDP forms a surrogate client. Each surrogate client accesses the relational database(s) on behalf of a program on GCOS 8.
The two sets of interface procedures - SIP and SCDP - manage the interactions with, respectively, the Server Interface Domain (SID) on GCOS 8 and the Thread Manager on UNIX.
DBSP uses a client/server architecture, which has the following structure.

• GCOS 8 programs act as clients, which request services (indirectly) from the RDBMS server.
• The RDBMS server provides database access for the GCOS 8 programs.
• The SQL statements that are extracted from GCOS 8 programs during the build process (see next paragraph) and moved to the DBSS act as surrogate clients. A surrogate client that contains compiled SQL statements accepts requests from a GCOS 8 program and initiates the execution of the requested statement to obtain data from the RDBMS.

6.2 Required Software

Software Delivered With DBSP

The following software components, with supporting documentation, are delivered as part of the DBSP product :

• DBSP software to operate on GCOS 8
• DBSP software to operate on the DBSS
• AIX software preinstalled on the DBSS. The FTP software that is required on the DBSS is included with AIX.
• MicroFocus COBOL and C compiler for AIX, preinstalled on the DBSS

Software Prerequisites on GCOS 8

The following software components must be installed on the GCOS 8 system before installation of the DBSP software :

• COBOL-85 Compiler
• Virtual C Compiler, which is required because SIP on GCOS 8 is implemented in C
• TP8 if you plan to implement TPRs that access Oracle databases
• FTP (File Transfer Protocol) software for transferring files between GCOS 8 and the DBSS.
• If the Virtual Machine Facility software is installed on a GCOS 8 system, the GOS and/or HOS copies of GCOS 8 can be connected to one or more DBSSs. Each HOS/GOS connection has its own copy of the DBSP software, but all share a single LCB connection to each DBSS.

Software Prerequisite on DBSS

The Oracle software - RDBMS plus Pre-Compiler (minimum configuration) - must be installed on the DBSS at the site before installation of the DBSP software.
Standard Oracle marketing rules apply to DBSP. Nevertheless, because of the combination of numerous Bull products (DBSP software, GCOS 8, high speed link, …) it is strongly recommended to consider DBSP support as a whole.

Software Prerequisite for High-Availability DBSS configuration (HA DBSP)

This paragraph only refers to the software that is prerequisite for the DBSS Systems. It does not consider the HA Software that might be needed for the disks that are connected to the DBSSs. A HA DBSP configuration requires Concurrent Resource Manager (CRM) to be configured on both the DBSSs involved in the HA Configuration. A HA-DPSP configuration might require Oracle Parallel Server (OPS) depending on the type of HA processing that has been chosen: If "Mutual Take Over" is elected, OPS becomes a prerequisite; while OPS is not required for a "Hot Standby" configuration.

7 Building and running DBSP Programs

7.1 The Build Process

The build process is one of the key features of the DBSP architecture, because it simplifies the development, testing, and installation of DBSP programs. The term "build process" is used because this process builds the GCOS 8 run units and UNIX executables for the DBSP program.

Next figure illustrates how the build process separates a DBSP program into the part that will execute on GCOS 8 and the part that will execute on the DBSS.

Build Process :
1. Compiles business logic on GCOS 8 and links object program with SIP
2. Compiles SQL statements on DBSS and Links object program with SCDP to from surrogate-client execut

Each DBSP program is developed in COBOL-85 with embedded SQL statements. The SQL statements must conform to the syntax and usage rules specified for the Oracle RDBMS.

The figure below illustrates the processing flow of the build process :
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(1) Output from all GCOS activities
(2) Output from all UNIX activities

During the build process, the CMA Generator separates the COBOL-85 source program into :

• a generated GCOS 8 COBOL source program that consists of the source code for the business logic of the program; this source program is then processed on GCOS 8 by the COBOL-85 Compiler and the Linkage Editor.
• a generated UNIX COBOL source program that contains only SQL statements; this source program is transferred automatically to the DBSS by means of an FTP file transfer initiated by the DBSP software on UNIX. The SQL statements are processed on the DBSS by the Oracle Pre-Compiler, the MicroFocus COBOL Compiler, and the MicroFocus Linker.

All of these activities proceed automatically, without developer intervention, after the build job has been initiated on GCOS 8. While separating the code to be executed on GCOS 8 from the code to be executed on the DBSS, the CMA Generator replaces each SQL statement in the GCOS 8 source with two sets of CMA function calls, one set that defines the function to be executed and the other set to receive the response (result or status) returned by execution of the function.

7.2 Logic Flow During Database Access

The combined software and hardware architecture of DBSP is illustrated in simplified form in next figure. To improve clarity, some parts of the logic flow are described below but are not shown in the figure.

When a DBSP compiled-and-linked program is executed on GCOS 8, execution proceeds as it would in any GCOS 8 program until the logic reaches a point at which an SQL statement appeared in the source. At this point, the generated CMA function calls are executed.

• Database access begins when the GCOS 8 program executes the first set of CMA calls to SIP (SQL Interface Procedure). The first set of CMA function calls identifies the surrogate client and SQL statement to be executed on the DBSS, and provides the variables to be used in execution of the SQL statement. Multiple CMA function calls are generated for each SQL statement. However, thinking of these calls in terms of two sets - one set that requests execution of a SQL statement, and one set that receives the response returned after execution of the statement - makes the logic involved easier to understand.

• SIP packs parameters for the SQL statement from the program into a message buffer and calls SID (Server Interface Domain).

• When called by SIP, SID interacts with the GCOS 8 Layered I/O System (LIOS) and the DBSS as follows :
- SID finds an available communication path to the DBSS. The communication paths available to SID are defined when the connection between GCOS 8 and the DBSS is configured.
- SID uses that path when initiating an I/O via LIOS. Because the DBSS is configured as a set of disk devices on GCOS 8, SID can use standard I/O calls to access the communication paths to the DBSS. To LIOS, calls from SID are identical to other I/O calls for data to be read from or written to a disk device.

• LIOS directs I/O to the DBSS via the Link Control Board (LCB) and the outbound SCSI channel.

• On the DBSS, the incoming request is passed from the I/O software to the Thread Manager. The Thread Manager directs the message to an available instance of the surrogate client.

• The surrogate-client executable, which includes SCDP, executes the SQL statement requested by the GCOS 8 program. The surrogate client preserves commitment-level context while interfacing with the RDBMS.

• The Oracle RDBMS processes the SQL statement exactly the same as if the entire program were operating locally under UNIX.

• The database and/or status information returned by Oracle is enclosed in a message that is returned via a call to the I/O software on the DBSS. The logic flow for this response is the reverse of the flow for the original call from the GCOS 8 program. The program on GCOS 8 receives the information returned from the DBSS by executing the second set of CMA function calls.
- The data, if any, retrieved from the relational database is returned to the GCOS 8 program in the data structure defined by the program's Data Division.
- Associated status and/or error information is returned to the program in the SQLCA (SQL Communication Area) in the Data Division.

NOTE :

The entire sequence of calls to the DBSS and responses from the DBSS is transparent to the GCOS 8 program, and to the developer of the program.

Data integrity is protected during access to DBSS-resident databases as follows.
The GCOS 8 program is protected by the standard GCOS 8 Integrity Control procedures, including checkpoint/rollback and program restart and recovery.

The surrogate client maintains the commitment state with the RDBMS on behalf of the GCOS 8 program. SID integrates the state of the GCOS 8 program with the state of the DBSS-resident database, to ensure that COMMIT and ROLLBACK are reflected correctly in the database.

8 Selecting a DBSP Configuration

This section describes each supported DBSP configuration, except the typical DBSP configuration made of one DBSS for one GCOS 8 system.

GCOS 8 System With HOS/GOS
One GCOS 8 System With Two Independent DBSSs
One GCOS 8 System With High-Availability DBSS Configuration
Two GCOS 8 Systems With Two DBSSs
One GCOS 8 System With Oracle on a Network Connected system

8.1 GCOS 8 System with HOS/GOS

A GCOS 8 system that is running the Virtual Machine Facility (VMF) software can be configured so that one or more Guest Operating Systems (GOSs) and/or the Host Operating Systems (HOS) can each access the same DBSS.


HOS = Host Operating system GOS = Guest Operating System SIP = SQL Interface Procedures SID = Server Interface Domain	LIOS = Layered I/O System LCB = Link Control Board ICU = Integrated Control Unit

If you use VMF to separate test and production programs by running them in different GOSs, you may want to use the same method to separate test and production versions of DBSP programs and databases.
You may also find VMF useful when developing and testing DBSP programs. You can develop and test new programs that are isolated in one GOS while non-DBSP programs run in a separate GOS.

8.2 One GCOS 8 System With Two Independent DBSSs

One GCOS 8 system can access two or more DBSSs.

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This configuration might be used in the following situations :

• A site has two major application groups, each of which accesses completely independent databases. The type of configuration shown in Figure 3-3 can provide increased parallelism in accessing the two databases, as contrasted to using a single DBSS for both databases. This scenario assumes that a single GCOS 8 multiprocessor configuration can handle the processing load of the business logic for both application groups.
• A site has one major application group that accesses a very large database. Logically segmenting the data into two Oracle databases provides increased parallelism in accessing the two segments. Depending on the programs and how the database is segmented across the two DBSSs, this type of configuration may also provide some degree of fail-soft capability in case of a failure of one DBSS.

8.3 One GCOS 8 System With High-Availability DBSS Configuration

The DBSP High-Availability (HA) option allows one GCOS 8 system to access a dual-DBSS configuration that control a single Oracle database or set of databases. The two DBSSs collectively form a single HA server.

In this configuration, the two DBSSs provide two equivalent paths to the same Oracle databases.

• The two copies of Oracle shown in the figure cooperate to access a single database while maintaining data integrity.
• The two DBSSs are configured redundantly to access the same database(s), thus sharing access to a common file system.
- When both DBSSs are operational, the DBSP software on GCOS 8 sends access requests to both DBSSs, attempting to keep both equally busy.
- If one DBSS or the path to it fails, all requests are sent to the surviving DBSS.

For organizations that need very high availability i.e.,in the range of 99.9% - the HA option is the appropriate choice. The HA option provides system redundancy to protect from any single point of failure in the DBSS hardware or in the connection between the DPS 9000 system and the pair of DBSSs that form the HA server.
The HA option provides the GCOS 8 system with two paths to a shared Oracle database. The failure of any of the critical hardware or software components of the HA server is recognized automatically and system operation continues without human intervention.

8.4 Two GCOS 8 Systems With Two DBSSs

Two GCOS 8 systems can share access to a database or databases managed by two DBSSs.


HOS = Host Operating system GOS = Guest Operating System SIP = SQL Interface Procedures SID = Server Interface Domain	LIOS = Layered I/O System LCB = Link Control Board ICU = Integrated Control Unit

Each DBSS in this configuration must run Oracle Parallel Server, so that the two copies of Oracle can share access to a single database or set of databases. The Oracle Parallel Server is a separately ordered option of the Oracle RDBMS.

This type of configuration could be used to provide increased processing power for a group of programs that access a single database or related set of databases.

8.5 One GCOS 8 System With Oracle on a Network Connected System

You can create a configuration that allows a DBSP program to access an Oracle database that is connected to the DBSS via TCP/IP and Oracle NET8.

In the configuration shown, DBSP programs on GCOS 8 access one DBSS, and the Oracle software distributes the access and update requests as necessary to other non-DBSP systems. This example shows a database distributed across a DBSS and an independent UNIX or Windows NT system, but other combinations are possible. Any combination of systems that Oracle supports in a distributed database configuration can be used as an extension of a DBSP environment.

• If you have already implemented Oracle programs and databases on another system or systems - AIX, UNIX, NT, etc. - before you install DBSP, this type of configuration allows interaction between those programs and databases and the DBSP programs and databases.

• This type of configuration could be used to allow applications such as ERP (Enterprise Resource Planning) that run on a UNIX or NT system to access Oracle databases managed by the DBSS. For example, this configuration would allow Oracle databases updated by TPRs on GCOS 8 to be accessed for a variety of reasons, such as :

- using the data in packaged applications such as ERP,
- making the data available to site-developed programs for purposes such as data analysis and reporting,
- making the data available to interactive users.

DBSP Technical Documentation

The DBSP Technical documentation consists of 3 documents :

67 A2 RJ28 : DBSP Programmer's guide. This Programmer's Guide provides information about the Database Server Processing (DBSP) Oracle Support product, and explains how to develop COBOL-85 programs with embedded Oracle SQL statements to operate on a DBSP configuration.

67 A2 RJ29 : DBSP Administrator's guide. This Administrator's Guide provides information about how to administer a Database Server Processing (DBSP) Oracle Support environment.

67 A2 SJ76 : DBSP software release bulletin. This document contains the installation instructions for the Database Server Processing (DBSP) Oracle Support Release 1.0 software.