HP DCE/9000 Version 1.7 Application Development Tools for HP-UX 11.0 Release Note

36 HP DCE 1.7 Application Development Tools Release Note
Developing DCE Applications with HP DCE/ 9000
Notes on Programming with HP DCE
Notes on Programming with HP DCE
The following are miscellaneous notes on programming with HP DCE.
Also see Programming with Threads on HP-UX (B2355-90060).
Several features of interest to programmers are not supported at the HP
DCE 1.7, including support for the rdaclif routines for ACL managers.
You should also be aware of future changes to threads support. For
details, see “Features Planned for a Future Release” in
Chapter 1 of Planning and Configuring HP DCE 1.7.
Appropriate Uses of the Cell Directory Service
The Cell Directory Service (CDS) was designed for a specific purpose: to
store and retrieve server bindings in a DCE cell. This mission implies
numerous assumptions about the volume of information that must be
stored and about the types and frequency of access to that information.
Performance trade-offs in CDS's usage of memory, disk, cache, the
network, and time-outs are optimized to this very specialized purpose.
The generality of the application programming interfaces to CDS masks
the specificity of this purpose, and gives CDS the appearance of a
general-purpose database system. It is not; the optimizations of CDS for
its low-volume and weakly-replicated storage, and for retrieval of server
bindings in a fairly static name space, are rarely optimal for other
purposes. Moreover, other uses of CDS directly compete and interfere
with its use and availability as a critical core component of the DCE
system.
Application developers are frequently tempted to use CDS for the direct
storage of information other than server bindings. For example, the
developer of a telephone number directory service may consider using
CDS to store the information directly. This is a bad idea, as the volume of
information could overwhelm the in-memory CDS data structures, and
very frequent read accesses could slow CDS performance and lock out
DCE server lookup requests. A much better strategy would be to
implement a database server designed specifically for the telephone
number directory service, and then store the bindings of that server in
CDS for lookup by clients. In this way, other uses do not compromise
CDS in its intended use as a critical DCE component.