Another Feature Falls from Windows 2000's COM+

When Microsoft Corp. shipped release candidate zero (RC0) of Windows 2000 last December, the company called the operating system feature complete, promising that between RC0 and gold code no new features would be added. Product managers and press reports used the words "fit and finish" to describe the state of the OS. Redmond, however, never promised to keep all the features in the operating system. It now seems some features don’t quite fit into the 35 million lines of code or won’t be finished in time for inclusion in the version Microsoft will shrinkwrap. As the company draws closer to releasing the final version, it thus far has removed at least two features.

In September, the company shifted the Windows Component Load Balancing (CLB) capability from Windows 2000 into AppCenter Server, a stand-alone product slated to ship in the second quarter of next year. The version of CLB that had been included in Windows 2000 Advanced Server Beta 3 is available as a free technology preview from Microsoft.

"The standalone [AppCenter Server] product is not all that much different from what Windows 2000 already had, but they gave it a different name and now they are selling it to customers," says Al Gillen, research manager, server operating infrastructure, at International Data Corp. (IDC,

When the second release candidate of Windows 2000 shipped in mid-September, the operating system contained an in-memory database (IMDB), which Microsoft added last April. Along with announcing RC2, the company informed developers that RC2 would be the last iteration of Windows 2000 to include IMDB.

This short-lived feature included an additional layer of cache memory designed to enhance performance between the operating system and stored data to increase performance for OLE DB-compliant data stores. The IMDB achieved this by caching at the middle tier and eliminating the need to go back to disk to access certain data.

A member of the SQL Server team says the IMDB was not an important feature as far as SQL Server performance is concerned.

The Transactional Shared Property Manager (TSPAM) feature, which was built on top of IMDB, also will be removed from Windows 2000, but the TSPAM technology itself will be available with COM+.

Microsoft says beta customers complained IMDB did not provide much additional benefit, and that the same benefits could be reaped by using SQL Server 7.0 along with Windows 2000.

A report by Laura DiDio, senior industry analyst for operating systems at Giga Information Group Inc. (, states that the biggest problem with IMDB was its lack of a query engine.

The report also states that beta tester complaints about both CLB and IMDB focused on difficulty deploying the products and lack of embedded management tools.

IDC’s Gillen points out that the IMDB also faced outside problems.

"To have a really effective in-memory database you need a 64-bit environment, but Windows 2000 is a 32-bit environment. So it is limited to 4 GB memory addressability, unless you take advantage of [Intel] Xeon’s 36-bit extensions," he says.

Although IMDB will not be a part of Windows 2000, Microsoft has not decided whether to develop the technology into a standalone product, integrate the capability directly into a future version of SQL Server, or simply drop the technology altogether.

The removal of IMDB and CLB, which were billed as strong points of COM+, raises the question of how significant the differences between COM and COM+ will be in the final version of Windows 2000.

IDC’s Gillen points out, however, that CLB and IMDB were not universal aspects of COM+, but rather were parts of Datacenter Server and Advanced Server only.

The Giga report states that removing pieces of the operating system and selling them as standalone products adds to the complexity of Windows 2000 because administrators will have one more thing to learn and to manage.

Falling Features

As of press time, three features had been dropped from what will become the final version of Windows 2000:

  • Component Load Balancing was removed from W2K and made part of AppCenter Server, a standalone product slated for release in the middle of next year.
  • The in-memory database (IMDB) that Microsoft added to Windows 2000 last April was scratched. Microsoft has no current plans for the technology.
  • The Transactional Shared Property Manager (TSPAM), which was built on top of IMDB, was dropped as a feature of the operating systems. The technology, however, is still available in COM+.

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