Introduction › JDBC Architecture in a Windows Environment

JDBC Architecture in a Windows Environment

The CA Datacom Server JDBC driver is a JDBC 4.0 compliant driver with the following characteristics:

• It implements the JDBC API which requires that your Java programs conform to the JDBC specification.
• It requires a Java virtual machine (JVM) and a JDBC Driver Manager.
• It can operate as a Type 1, Type 2, Type 3, or Type 4 JDBC driver, depending on the type of connection used.

CA Datacom Server supports both 32- and 64-bit applications, although as with any JVM, only a 32-bit application is supported in a 32-bit JVM and only a 64-bit application is supported by a 64-bit JVM.

The following flowchart shows the relationship of CA Datacom Server to applications that use JDBC to access CA Datacom/DB mainframe data.

The following information describes each of the JDBC architecture components:

Application (Windows)

Java SQL based applications using the JDBC interface and running under a Java virtual machine supporting JDBC 4.0, can access data in a CA Datacom/DB database using a 32- or 64-bit application. An application can be either a stand-alone Java application using JDBC or a web based application that uses some type of web server. An application issues a DriverManager.getConnection or uses a JDBC DataSource interface to connect to the JDBC Driver Manager for a specific driver, such as the Server JDBC driver.

JDBC Driver Manager (Windows)

The JDBC Driver Manager is part of the Java virtual machine. Applications connect to the JDBC Driver Manager and the JDBC Driver Manager can connect to any number of drivers. The JDBC Driver Manager forwards an application's connection request to the appropriate driver based on the Uniform Resource Locator (URL) specified in the connection request.

CA Datacom Server JDBC Driver (Windows)

The CA Datacom Server JDBC driver is a JDBC 4.0 compliant driver with some exceptions. The JAVA classes that constitute the Server JDBC driver reside in the cadcjdbc.jar file.

Drivers that are connected by the JDBC Driver Manager interpret calls from the application and the JDBC Driver Manager and make calls to the requested DBMS. The Server JDBC DataSource classes can be used to produce Connection objects that participate in connection pooling, and in subsequent release distributed transactions.

CA Datacom Server JDBC Type 4 Driver

In a z/OS environment, CA Datacom Server provides a JDBC Type 4 driver which allows direct connection to the Mainframe Server component address space with pure Java connections using TCP/IP. The Type 4 driver connection method is invoked by a connection URL as //host:port/ where host is the IP address or DNS name of the host machine where the Mainframe Server component resides, and port is the port number specified in the Mainframe Server component startup parameter TCPIP_PORT=.

CA Datacom Server Proprietary Interface (Windows)

The cadcdb32.dll/cadcdb64.dll modules provide the CA Datacom/DB proprietary interface, data mapping, data translation, and data communication services for Type 1, Type 2 and Type 3 driver connections. It also supplies the CAICCI or native TCP/IP interface (z/OS only). A CAICCI request is sent through CAICCI-PC and CAICCI to the Mainframe Server component on the host mainframe.

A native TCP/IP request from a Type 4 driver connection is sent through the data stream directly to the Mainframe Server component. A Type 4 driver connection bypasses the cadcdb32.dll/cadcdb64.dll modules and connects directly to the Mainframe Server component using TCP/IP (z/OS only).

CA Datacom Server JDBC Proxy

The CA Datacom Server JDBC Proxy is an optional background process that provides a TCP/IP interface for Type 3 driver connections. The Proxy can run under either a Windows server or under USS (z/OS only). The Proxy is invoked if specified by the connection URL as //host:port/ where host is the DNS name or IP address of the Windows machine where the Proxy resides and port is the listener port assigned to the Proxy.

CAICCI and TCP/IP (Windows and Mainframe)

CAICCI isolates CA Datacom Server from the communication protocol used between the workstation and mainframe. It is the communication protocol traditionally used with CA Datacom Server. CAICCI-PC is optional. Through JDBC Data Source Properties or the connection URL, you can choose the type of connection for the application.

CAICCI is required on the host mainframe and is used for communication between Mainframe Server regions and the Server SVCOMPR utility.

TCP/IP is the basic communication language or protocol of the Internet. CA Datacom Server supports native TCP/IP data transmission between workstations and z/OS host mainframes. It does not require CAICCI-PC. Through mainframe server startup parameters, you can choose to allow both CAICCI and TCP/IP or CAICCI, only.

CA Datacom Server Mainframe Server Component (Mainframe)

The CA Datacom Server Mainframe Server component executes in its own address space and connects to a specific MUF. It processes connect requests from client applications, handles data transmission requests to and from client applications, and translates data between MUF and client applications.

In a z/OS environment, the Mainframe Server component provides support for native TCP/IP data transmission between workstations and host mainframes. Through startup parameters you can allow native TCP/IP transmissions. If a JDBC Type 4 driver is desired, TCP/IP must be allowed in the Mainframe Server startup parameters.

Multi‑User Facility (Mainframe)

A MUF provides the ability to access any CA Datacom/DB database concurrently from multiple regions. Each server communicates with only one MUF, but a system can have multiple MUFs accessed by multiple servers or multiple servers accessing the same MUF.