Janus Web Server

Janus Web Server is part of the Janus family of products that provides connectivity to the Model 204 database.

A site that has Janus Web Server must have the Janus TCP/IP Base because without it, it is impossible to use Janus Web Server. A Janus Web Server site might also have one or more of the other products in the Janus family, though no others are required. Note that if Limited Janus Web Server is available, then Janus TCP/IP Base is automatically authorized. Limited Janus Web Server is a free, restricted version of Janus Web Server.

The Janus Web Server programmer API is implemented as the Janus Web Server $functions.

Janus, the Sirius Mods, and UL/SPF

The Janus family of products is itself made up of two distinct components:

• A collection of object code enhancements to the Model 204 database-engine nucleus. These enhancements are distributed as components of the Sirius Mods and make up a collection of products including those in the Janus family. The Sirius Mods include many non-connectivity related products (such as Fast/Backup, Fast/Reload, and the Fast/Unload User Language Interface) that are not part of the Janus family. No Sirius Mods products are required to run Janus Web Server other than itself and Janus TCP/IP Base.
• A collection of Model 204 procedures that contain User Language, documentation, and assorted other data. These Model 204 procedures install and implement the components of the User Language Structured Programming Facility, also known as UL/SPF. All the UL/SPF files reside in the SIRIUS procedure file (as of Sirius Mods version 6.8). which also contains code and data useful to Janus users including Janus Web Server users. UL/SPF also includes files that are components of non-connectivity related products such as SirPro, SirScan, and SirMon. No other UL/SPF products are required to run Janus Web Server, or any other Janus product, for that matter. Thus, to install Janus Web Server, both the Sirius Mods and UL/SPF must be installed, following the instructions in the Sirius Mods Installation Guide and the UL/SPF Installation and Maintenance Guide, respectively. When the Sirius Mods are installed, all other products owned by the installing site that are part of the Sirius Mods will also be installed. Similarly, when UL/SPF is installed, all other products owned by the installing site that are part of UL/SPF will be installed.

Versions and compatibility

Because the Sirius Mods and UL/SPF have somewhat different release cycles, the version numbers for these two components will often differ in a distribution. For example, version 7.6 of the Sirius Mods might be shipped with version 7.3 of UL/SPF. All the products in UL/SPF depend on certain features being present in the version of the Sirius Mods that is installed in the Model 204 load module under which UL/SPF is running. This implies, obviously, that the Sirius Mods must be installed for any UL/SPF component to operate correctly. And, as of version 6.8, the Sirius Mods version must match or be higher than the UL/SPF version number.

The Sirius Mods however, do not depend on any particular features of the UL/SPF product, merely the presence of the UL/SPF SIRIUS file. The SIRIUS file contains the code for the sample Janus Web Server, and Janus port definitions have default rules that call to this file. Sirius Software has a strong commitment to backward compatibility with the Sirius Mods.

This means that any User Language application (including UL/SPF) that uses the Sirius Mods will run correctly on subsequent versions of the Sirius Mods. It is, thus, always possible to upgrade the Sirius Mods without having to worry about upgrading UL/SPF. This is not to say that this is always a good idea, only that it is possible and that the installed version of a UL/SPF product will continue to run as it had before the Sirius Mods upgrade.

While the Janus family of products has a UL/SPF component, most of the critical code is actually in the Sirius Mods — object code enhancements to the Model 204 nucleus. The UL/SPF component of the Janus family consists mostly of utilities, examples, and documentation. Because of this, the version number of a Janus product is generally considered to be the version of the Sirius Mods in which it is contained. Janus Web Server was first available in version 4.4 of the Sirius Mods, so the first version of Janus Web Server was actually called version 4.4.

This document, the Janus Web Server Reference Manual, assumes that a site is running Sirius Mods version 6.7 or later and has installed UL/SPF version 6.2 or later. Any documentation that requires a later version of the Sirius Mods or UL/SPF will be clearly marked to indicate this. For example, a JANUS DEFINE parameter that is only available in versions 7.7 and later of the Sirius Mods will have a sentence such as “This parameter is only available in version 7.7 and later of Sirius Mods” in its documentation. If a feature, $function, command, or parameter is not indicated as requiring any specific version of the Sirius Mods, it can be assumed that it is available, as documented, in all versions of Janus Web Server; that is, all versions since version 6.7 of the Sirius Mods and version 6.2 of UL/SPF.

Additional Janus Web tools

Janus Web Server is distributed with two utilities: SIRPIPE and SIRPUT. These can be used to facilitate loading of binary and text data into Model 204 procedure files. Both utilities are distributed as stand-alone load modules that requires a separate (though simple) installation from the Sirius Mods and UL/SPF.

Janus Web Server also includes a facility called Janus Web Legacy Support. Not a separate product, this is a standard part of Janus Web Server. By converting 3270 screens into HTML pages, Janus Web Legacy Support makes it possible to access existing 3270 applications from a browser. For more information about this feature, see Janus Web Legacy Support.

Related documentation

As mentioned above in [[#Janus, the Sirius Mods, and UL/SPF|“Janus, the Sirius Mods, and UL/SPF”]], Janus Web Server requires the installation of both the Sirius Mods and UL/SPF. As such, the person responsible for the installation of Janus Web Server should refer to the Sirius Mods Installation Guide and the UL/SPF Installation and Maintenance Guide.

The Sirius Messages Manual contains documentation on Sirius Mods error messages, so it might be useful to application programmers.

Janus Web Server depends on the Janus TCP/IP Base product, and there is much useful information in the Janus TCP/IP Base Reference Manual.

You are authorized to use a number of Sirius $functions along with Janus Web Server, including procedure processing $functions and $list processing $functions. Unless otherwise stated, documentation for these functions, and any $functions mentioned but not documented here that are not standard Model 204 $functions, is accessible via the "List of $functions".
Note: One of the limitations of Limited Janus Web Server is that it only authorizes the $WEBxxx functions; it does not authorize the other Sirius Functions, which are authorized by a full Janus Web Server license.

For details about date processing relevant to some of the Janus Web Server $functions, see "Datetime string formats".

Related products

The Janus TCP/IP Base must be installed to use Janus Web Server. This is the only other Sirius Mods product that must be installed in a Model 204 region to use Janus Web Server.

If security is a concern, whether it be internet or intranet security, SSL (Secure Socket Layer) is the de-facto standard for providing encryption and validation security for webbased applications. The Janus Network Security product provides SSL support for Janus Web Server (as well as other products in the Janus family).

One of the convenient debugging features available with Janus Web Server is a TRACE facility which logs Janus request/response information to the Model 204 journal. In addition, most application debugging in a Model 204 environment is done on a 3270 or 3270 emulator — but since Janus Web Server applications are not associated with a 3270, debugging techniques geared toward a 3270 will not work for them, so most of their debugging information goes to the Model 204 journal. If you don't have good tools to view the journal, using it for debugging is a tedious process. AUDIT204 and ISPF provide some capabilities for viewing the journal, but they have many inherent shortcomings and inefficiencies. Because of this, it is strongly recommended that any site that installs Janus Web Server also install SirScan.

SirScan is a product in the UL/SPF family that facilitates the interactive extraction of journal information within the Model 204 region. It does so via a user-friendly web browser or full-screen 3270 interface and low-level routines to provide efficient access to in-memory and on-disk journal buffers. SirScan can provide an order of magnitude improvement in debugging efficiency for non-terminal-related Model 204 processes such as Janus Web Server, Horizon, BATCH2 and other Janus server applications. Note: If Limited Janus Web Server is available, SirScan is automatically authorized for viewing audit trail entries on WEBSERV threads. For more information about Limited Janus Web Server, see “Limited Janus Web Server” on page 5.

System requirements

The current release of Janus Web Server requires the following components to run:

• Mainframe operating systems:
• Any supported version of z/OS
• z/VSE Version 4 or later or
• CMS (releases currently supported by IBM) running under any supported version of z/VM
• Model 204 Version 6 Release 1 or later
• One of the following mainframe TCP/IP implementations:
• IBM TCP/IP for z/VM or z/OS
• InterLink TCP/IP for MVS - Version 1.1 or later
• TCP/IP for VSE (Connectivity Systems, Inc., Columbus, OH) - Version 1 Release 4.0 or later
• Any HTTP 1.0 or later compliant browser such as Mozilla Firefox 1.0 or later or Microsoft Internet Explorer 6.0 or later, or virtually any other browser

Limited Janus Web Server — Free Use of Janus Web Server

The Limited Janus Web Server capability allows you to write limited-scale Janus Web Server applications without requiring you to purchase a copy of Janus Web Server. This allows you to implement low-volume applications using the power of the Web, even if your only Sirius Mods product is, for example, Fast/Backup or Fast/Reload.

The Limited Janus Web Server capability is automatically created in any Model 204 load module that has at least one Sirius Mods product authorized and does not contain authorization to Janus Web Server. The duration of that capability is the maximum duration of any of the authorized Sirius Mods products. See the Overview chapter in the Sirius Mods Installation Guide for a list of all products that are in the Sirius Mods.

Limited Janus Web Server consists of the following:

• Authorization to use the $WEBxxx functions (“Janus Web Server API ($functions)” on page 125).
• If Janus TCP/IP Base is not otherwise authorized, authorization to it with 3 threads.
• Authorization to define and use Janus Web Server (WEBSERV) ports with up to 3 connections.
• Authorization to use SirScan to view the audit trail entries of any WEBSERV thread.
• Authorization for the HTML/TEXT statement and the SIREDIT and WEBAUDIT parameters.
• Customer support and maintenance for Limited Janus Web Server. The limitations imposed in Limited Janus Web Server are as follows, relative to a full Janus Web Server license:
• At most 3 concurrent Janus WEBSERV threads may be active.
• The only $functions authorized by Limited Janus Web Server are the $WEBxxx ones; Janus Web Server authorizes many $functions beyond the $WEBxxx functions.

Sirius Software will encourage and assist users among its customer base to develop applications that can be shared among Limited Janus Web Server and Janus Web Server customers. Of course, Sirius Software hopes that the functionality provided by Limited Janus Web Server convinces you to purchase full Janus Web Server and SirScan licenses.

References and links

• Category:Janus Web Server $functions
• List of Janus Web Server $functions
• Understanding Web Processing
• List of Janus commands
• Getting started with Janus Web Server