The CICS Web Support (CWS) was introduced in September 2000 together with CICS Transaction Server for VSE/ESA 1.1.1 (CICS TS) and VSE/ESA 2.5. Since then HTTP requests can be sent directly from the Web browser to the CICS TS without the need for an intermediate gateway. CICS processes the request and returns the results to the Web browser.

The addition of EXEC CICS application programming interface commands for the manipulation of web entities allows the definition and management of HTML files.

How does it work ?
A Web browser is an HTTP client. The Web browser constructs an HTTP request, which is passed across the network to the TCP/IP server on z/VSE. The TCP/IP server relays the request to the CICS Web Interface on CICS TS, which calls a CICS program to service the request. The output from the CICS program is sent back to the Web browser in an HTTP response.

The CICS Web Support comes with the 3270 Bridge, which allows existing (3270) applications to be integrated into new applications. That is the 3270 Bridge can be used to provide Web browser access to existing 3270-based transactions without requiring any application changes.

Finally a recommendation from CICS Level 3 for the CICS Web Support:

If you use CICS Web Support TCPIPSERVICEs and applied APAR PM60076, please apply APAR PM74905 too. Otherwise you could encounter a severe storage leak. This is also discussed on VSE-L.

Symptom: The least that will happen is that a CEMT P SHUT (normal shutdown) will hang, and the worst is that you will get SOS (short on storage). You may see a large number of "SOSTE" (STE socket control blocks) in the Extended CICS Dynamic Storage Area (ECDSA). You can avoid the hang condition by using CEMT P SHUT IMM.

Always check for the latest fix status at CICS TS fix list.

Tags:  cics vse cws service apar tcpip