The mvBase Server is the database engine which typically maintains the MultiValue database in virtual memory storage files. There is typically one mvBase Server component per installation. In the current implementation, the mvBase Server name is the same as the network name of the system on which it is installed.
To accommodate client connections and console user requirements, the Server component may be run as an application or as a service.
When executing the mvBase Server component as an application, the Server runs as a foreground process and as with all Windows applications, it is terminated when the console user logs off the Windows system.
When executing the mvBase Server component as a service, this Server component runs as a background process and continues to run when the console user logs off the host operating system and client connections to mvBase are maintained.
In addition, as a service, the Server component can be configured to start automatically with the Windows host operating system, eliminating the need for a user to log on to the console at all.
The mvBase Server’s method of execution also affects available start up options. Server component startup can be automatic or manual. See Configuring and Using the mvBase Server or the Administration Utility Help System for additional information about these two Server methods of execution and configuration options.
The mvBase Server contains the general software application processing engine and database management system. Software applications running on the Server are typically written in mvBASIC and are run on processes.
A process is the basic element of execution on the mvBase Server. Associated with each process is a PIB (process ID block), a PCB (process control block), and a block of workspace frames. The WHO and WHERE commands report information about a process. Processes can be linked to lines that are externally addressable and user-interactive.
A phantom process is a process that does not have a line linked to it. If the user configures an mvBase environment with more processes than lines, the remaining processes are considered phantom processes at boot time. The user can also create phantom processes when mvBase is running simply by unlinking a process/line pair.
An mvBase line is a logical construct that serves as a bridge between mvBase client applications and mvBase Server processes. Associated with each line is a LIB (line ID block), which defines for the line the information traditionally associated with communication devices (baud rate, parity, etc.), as well as a number of constructs unique to mvBase.
A line on the mvBase Server component is a different and separate entity from a process. It is not necessary to have an equal number of lines and processes on a system, but in order for a process to be interactive, it must be linked to a line. The link between lines and processes may be manipulated using the LINK-LINE and UNLINK-LINE commands. The default, at boot time, is to link process 0 to line 0, process 1 to line 1, etc., until either processes or lines are exhausted.
Phantom lines are lines not connected to an associated process. Phantom lines may be used to communicate with external devices or data channels via the CONVERSE command or with mvBASIC I/O command extensions.
The aspects of the mvBase Server which may be configured are located in the Server tab of the Administration Utility, and include:
Virtual memory storage files (quantity, size, order and number)
The quantity of required mvBase processes and lines
Execution mode (application or service)
Startup options (manual or autoboot)
The Fileload option (whether a fileload is to be done when the Server is started)
The number and type of tape devices initially assigned Logical Tape Units (LTU*)
Authorization/Licensing
*A logical tape unit (LTU) is any physical tape device, floppy disk, virtual tape file (a file which acts as a tape device) or virtual tape link (a communications pathway between two mvBase Servers that acts as a read-only or write-only tape device). See Base Peripheral Devices Overview for additional information.
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NOTE |
The SYSPROG account in the mvBase database is used by the system administrator to control and configure the MultiValue database itself, as opposed to the mvBase Administration Utility, which is used for configuration and control of the mvBase Server as described above. |
See Also