HOWTO: Create an MTS Component that Works with FoxIsapi

• Microsoft Visual FoxPro for Windows, version 6.0

SUMMARY

Visual FoxPro 6.0 contains many server improvements including those that allow better integration with Microsoft Transaction Server (MTS). There may be situations where you want to use an MTS component with FoxIsapi.

MORE INFORMATION

FoxIsapi is an Internet Server Application Programming Interface (ISAPI) extension that allows for Visual FoxPro (VFP) servers to be used with Internet Information Server to generate server-side HTML Web pages. The URL includes the VFP server, which is instantiated, and the associated method to be invoked. The method returns HTML to be rendered by the Web browser.

There are no specific requirements for VFP servers used with FoxIsapi, however, best results are often obtained with use of Local EXE servers since it is easier to protect global data. The FoxIsapi sample uses a form so that it can obtain a private data session.

One of the benefits of FoxIsapi is its built-in Pool Manager, which lets you manage multiple running servers pooled together for maximum scalability. One can efficiently use FoxIsapi to handle Web sites that need to respond to hundreds of thousands of Web hits a day.

With all the nice features offered by MTS, one could easily use MTS along with FoxIsapi. While the improved scalability offered by MTS would not necessarily be taken advantage because of the FoxIsapi architecture, the Pool Manager support may provide an even better alternative. One of the nice advantages of using MTS is its automatic security and transaction support. These are reasons to consider using MTS with FoxIsapi. Remember, MTS components must be In-Process DLLs (marked as Multi-Use). One should not need to perform any other special tasks in order to get these servers to work under FoxIsapi. In addition, one can call other MTS servers directly within your FoxIsapi servers since these all exist within same MTS activity.

The Pool Manager controls how servers scale, and how many instances can run simultaneously. Make sure you test various Pool Manager scenarios to get optimal results. You can also setup load balancing across multiple computers to make further scalability improvements. Strategies such as DNS Round Robin schemas are options to consider for load balancing.

REFERENCES

Microsoft Transaction Server Help; search on: "COM Components"

Additional query words: PGFest600 kbVFp600 kbISAPI kbMTS

Keywords :
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbhowto