ZIM SERVER – 4GL APPLICATION FRAMEWORK

Zim Client/Server Architecture

Zim 9 operates under a robust client/server architecture, where Zim Server serves as the central hub. Clients, including Zim, Zim Thin Client (ZIMTC), and ZimExplore, connect to Zim Server to access and manage databases.

Key Features:

Single Instance Management:
- Only one instance of Zim Server can run on a machine, but it can manage multiple databases simultaneously.
Database Connectivity:
- Databases under the same Zim Server can connect using the CONNECT command, enabling data sharing and interaction. The DISCONNECT command terminates this connection.
Flexible Client Deployment:
- Clients can operate on different machines and operating systems, such as Windows or Unix, providing flexibility in application deployment.
Heterogeneous Environments:
- Supports mixed environments, allowing Windows clients to access Unix-hosted databases and vice versa. This setup can include simultaneous operation of clients on both Windows and Unix.
Data Accessibility:
- Data from one database can be made visible to applications running on another database, ensuring full concurrent control and safety.

Connectivity Options:

Single Zim Server: Connect databases managed by the same Zim Server.
Multiple Zim Servers: Connect databases managed by different Zim Server instances on separate machines.
Chained Connections: Establish connections between multiple databases across different servers.

Benefits:

Cross-Platform Applications: Run Zim applications on different machines from the server, such as a Windows application interfacing with a Unix-based Zim Server.
Integrated Environments: Combine graphical interfaces on Windows with text-based information on Unix, enhancing user experience and operational efficiency.
Secure Data Sharing: Retrieve and update data across databases with full safety and concurrent control.

This guide provides detailed instructions on implementing and utilizing connectivity between Zim databases. For more information, please refer to our comprehensive documentation.

Starts and stops the Zim Server program.

Linux Syntax

[nohup] zimserver [-k] &

Windows NT Syntax

[start] zimserver [-k] [-i] [-s [-e] [-u]

Parameters

-k	optional parameter to gracefully stop Zim Server
-i	optional parameter to install Zim Server as a Windows Services
-s	optional parameter to start an already installed Zim Server from the Windows Services
-e	optional parameter to stop the execution of a started Zim Server from the Windows Services
-u	optional parameter to uninstall Zim Server from the Windows Services

Comments

Before starting Zim Server, ensure that the ZIM environment variable is set to point to the directory where ZIMSERVER was installed.

ZimServer must always be started with the Administrator’s (root) privileges.

Tracing and logging information is outputted to zimsvlog.zim.

After starting Zim Server, you should see a message stating that Zim Server has started or it has failed to start. In the latter case, you can check the reason for Zim Server not starting in zimsvlog.zim.

When stopping Zim Server, a message will follow indicating that Zim Server was terminated.

WARNING: Always stop Zim Server using the -k parameter. If you do it in a different way, Zim Server might not be able to finish an ongoing checkpoint of committed transactions to disk. Depending on the size of some configuration parameters, the checkpoint procedure might take several seconds after all transactions have finished and after all users have been disconnected. Even though the next time you start Zim Server it checks for unfinished checkpoints (and finishes them), if you copy or backup files from the database at this point you might get files in an intermediary and inconsistent state.

To make sure that your databases are consistent in case you mistakenly stopped Zim Server not using the correct procedure, just start Zim Server again and then stop it in the recommended manner.

UNIX

ZIMSERVER can be started by manually entering the above command or the command line can be inserted into your system’s start-up script. ZIMSERVER should always be started using NOHUP. NOHUP ensures that the Zim Server process continues to run even if you log out. The ‘&’ at the end of the command line enables you to enter more commands at your terminal after the server has been started.

If you use NOHUP, some special output from ZIMSERVER goes to a file called nohup.out located in the directory that was current when the NOHUP command was executed. As with the file zimsvlog.zim, nohup.out is always added to and can become very large. You should check its size from time to time, archive it (if you wish), and erase it. The NOHUP also allows you to close the Unix session without exiting ZimServer as well, that is, ZimServer keeps running in the background, provided that you have used the symbol “&”.

Windows

The server can be started from a shortcut on the desktop, in a text console window, or using the start command from a console window. When using any of these startup methods, the output is displayed in the startup window.

Also, Zim Server can be installed as a Windows Service using -i parameter. After installing Zim Server a Windows Service, you can control Zim Server from the Services window or from the command prompt.

net start zimserver To start the service from the command prompt

net stop zimserver To stop the service from the command prompt

PLEASE NOTE: If you start ZimServer as a service you should use the service option to stop the server instead of using the -k parameter.

To remove ZimServer from Windows services you will need to use -u parameter.

The zimsvlog.zim file

The log file zimsvlog.zim, located in the directory pointed to by the ZIM environment variable, records all events happening with Zim Server like, its start, its end, errors, tracing, and other information.

You can browse its contents using a text editor or using ZIMEXPLORE.

After some time using Zim Server, this file can become very large. You should check the size of it from time to time, archive it (if you wish) and erase it. It can be erased at any time, even when Zim Server is running. Next time Zim Server needs to log some information, the file will be recreated.

Category: ZIM SERVER

About Zim Integrated Server