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OSF's Distributed Computing Environment
White Paper 5/13/92
HP and DCE
**********
HP has been making significant strides in the area of defining industry
accepted standards for distributed computing that gives HP a competitive
edge today as our customers move towards open systems and distributed
applications.
HP has been the leader in offering several solutions, including
Network Computing System, HP LAN Manager/X, Passwrd Etc and HP Diskless
to Open Software Foundation (OSF) to comprise its Distributed
Computing Environment (DCE).
These solutions were submitted as part of an integrated technology
collection known as DEcorum, which stands for "Distributed Environment
Core" software, jointly submitted by HP, IBM, DEC, Transarc, and Locus.
HP's role in supplying technology to OSF for DCE integration has
positioned us as the leader in providing the most competitive solutions
for distributed computing today and in the future. Our work with OSF
DCE further validates HP's Team Computing and NewWave Computing
strategies. In fact, some of the key product implementations of the Team
Computing and NewWave Computing strategies have been endorsed by the OSF
DCE definition today.
It is important for our computer selling strategy to emphasize with our
current and prospective customers the importance of OSF DCE and the
major contributions HP made to it. You should be able to confidently
demonstrate to your customers that investing in HP guarantees them a
stake in the Open Systems environment, more so than any other vendor.
In OSF and DCE, one must appreciate that OSF plays a special role in the
computer industry. A non-profit company, OSF solicits the input of the
entire industry to acquire and develop the technology required to create
a vendor-neutral computing environment. Its membership represents every
segment of the worldwide computer community -- system vendors,
independent software vendors, end users, government agencies, research
centers, and universities.
OSF has defined the Distributed Computing Environment (DCE) to solve the
industry-wide problem of transparent computing in heterogeneous
environments, facilitating the creation and use of distributed
applications.
DCE addresses several business needs including:
1. Interoperability: As computing environments become more
heterogeneous, a growing business need is to be able to share and
manage data transparently in a heterogeneous network.
2. Ease of development and porting of applications: DCE provides
development enablers that provide consistency for VABs and VARS to
create distributed customized applications in a heterogeneous
environment.
3. Security: As networks grow in complexity and number of users,
security requirements have also been growing. DCE provides data and
directory security between two or more heterogeneous machines as in
a single system.
4. Performance: DCE focuses on distributed processing performance in
a distributed heterogeneous network, since from a business need
applications need to perform as well in a distributed environment
as they do on a single system, despite the network overhead. (In
some cases, distributed computing should deliver superior
performance to a single system by allowing application tasks to run
in parallel on the network). By using the DCE RPC, applications
can be optimized to move the processing and data access to systems
with the best resources.
5. Availability: Data must be made more available throughout a
company, irregardless of where the data is kept. Therefore, it
is an objective for DCE to provide the same or better level of
availability as a single system. A network of systems has
inherent fault-tolerance: if one system fails, another system on
the network can potentially take up the work of the failed
processor.
6. Scalability: DCE allows a network to grow with minimal impact
on performance or administration. Using DCE Global Naming,
networks and applications achieve location transparency.
The OSF technology DCE includes remote procedure call (RPC),
global naming, security, diskless operations, a distributed file system,
distributed time synchronization, multiprocessing {threads} support, and
future integration with the OSF Distributed Management Environment, or
DME.
HP formed a partnership with IBM, Transarc, Microsoft, DEC, and
and Locus to jointly submit DEcorum in response to the OSF Request for
Technology for OSF DCE. DEcorum is a set of integrated software
components that provide the functionality required by OSF's Distributed
Computing Environment.
The following chart outlines the major technology areas of OSF DCE, the
DEcorum technology submittals for each area, and the OSF endorcement
for each area. As can be seen below, HP clearly played a leadership
role in the submittal of technologies, and also came up a winner when
one regards the technologies that OSF accepted for inclusion in DCE.
____________________________________________________________________
| What What the Technology |
| Technology DEcorum OSF Supplier |
| submitted accepted |
|_________________________________________________________________ |
| |
| RPC NCS NCS HP with DEC |
| extensions |
| |
| Security Passwrd Etc Passwrd Etc HP |
| Kerberos Kerberos M.I.T. |
| |
| |
| Threads Recommended CMA DEC |
| P-threads on CMA |
| |
| Time Recommended DTS DTS DEC |
| |
| Naming NCA Naming CDS DEC, with RPC |
| interfaces |
| from HP |
| Distributed AFS DFS Transarc |
| File System |
| |
| PC LM/X LM/X HP/Microsoft |
| Integration PC/NFS SUN |
| |
| X.500 No DIR-X Siemens |
| submission |
| |
| Diskless HP Diskless HP Diskless HP |
| Operation |
| PC/NFS SUN |
| |
|__________________________________________________________________|
HP is a leader in providing the technology accepted by
OSF for DCE. This includes support for the RPC, the security component,
diskless operation, and naming facilities. The distributed
file service, DFS, includes HP's NCS enhancements as well.
HP not only earned acceptance of its proposals, it also has products to
back them, as shown by the chart below:
Availability
Technology Domain HP-UX MPE/ix
---------- ------ ----- -------
NCS NCS 1.5.1 Now NCS 1.5.1 Now NCS 1.5.1 on MPE
4.0
Diskless UNIX support ----- NOW -----
LAN MANAGER ----- NOW LAN MANAGER API's
Passwrd, Etc. NOW Future ------
As can be seen above, HP has taking the lead for providing major
components of OSF DCE even before OSF DCE will be available. HP is
committed to support OSF DCE on HP-UX multiuser systems and
workstations as soon as possible after OSF DCE source is provided to
licensers. OSF DCE components are also actively being investigated and
brought to MPE/ix.
DCE Product Availability
DCE Core Developer's Environment: Includes NCS RPC, Cell Directory
Service, Distributed Time Service, Security Service and threads will be
available on both HP/UX and MPE.
HP/UX Core release will be in the fall of 1992. MPE/ix will follow
about six months later with availability in the spring of 1993.
DCE End-User services including the Distributed File System and Discless
will follow in subsequent releases in 1993 for HP/UX. They are being
investigated for MPE.
In addition, both HP/UX and MPE/ix will be launching early access
programs prior to actual product release. Contact the Network Sales
Center for information on these programs.
NOW WHAT DOES THAT MEAN TO YOUR CUSTOMER?
-----------------------------------------
Migration to OSF DCE will not be a problem on HP-UX.
since several of the key components of OSF DCE are available today
or in the near future.
In addition, several of the components of OSF DCE, such as Discless,
Passwrd, Etc, and DFS are "turnkey" solutions, not requiring additional
programming by your customer. Some DCE components, such as NCS, can be
used as tools by ISVs and end-user customers for customized distributed
computing that best fits the particular business needs of the end-user.
DCE provides standard API's; NCS RPC and the directory API called XDS
so that developers can develop DCE Distributed applications and port
them easily on any platform supporting DCE.
TECHNOLOGY OVERVIEW
-------------------
1. Remote Procedure Call -- HP's NCS allows individual procedures in an
application to run on a computer(s) elsewhere in the network. OSF
accepted NCS as the RPC mechanism supporting direct calls to
procedures on remote systems, enabling programmers to develop
distributed applications easily in multi-vendor, multiple system
environments.
NCS features include:
1. Data type conversion between dissimilar machines.
In NCS, a receiving procedure needs to convert data
representations only when the sending machine's data types
differ.
2. Transport independence and transparency.
NCS does not rely upon any transport-layer features such as
error correction and detection. This allows it to run over
unreliable transports, such as UDP. With version 2.0,
connection oriented transports such as ISO TP4 are supported.
3. Location independence.
NCS determines at runtime where network resources are, such as
remote sub-procedures and databases.
Some other things you should know about NCS:
1. NCS is popular as an RPC because it follows local procedure
call semantics more closely than other RPCs. This makes it
easier for application developers to quickly pick up and learn.
2. Using NCS, no performance is lost due to unnecessary data
translation. Only when data conversion is necessary, does NCS
translate from the sending procedure's format directly into the
receiving procedures format.
3. NCS 2.0 is well positioned to take advantage of ISO protocol
standards as they emerge. NCS 2.0 supports OSI presentation
layer negotiations for data representation format. NCS 2.0 can
also operate over the ISO/TP4 transport protocol. And NCS 2.0
supports environments using global naming services such as
ISO/CCITT X.500 name services.
4. NCS was chosen by OSF over other RPCs such as ONC RPC from SUN
and RPCTool from Netwise because:
. ONC imposes limits on the size and number of arguments that
can be passed between applications and remote sub-
procedures, whereas NCS imposes no such limits.
. RPCTool provides too many "hooks" for programmers to
customize the RPC, leading to incompatible versions of the
protocol and defeating the purpose of providing a standard.
By contrast, NCS does not leave doors open to interpretation
by programmers.
. ONC has no mechanism to send and receive indeterminate-length
streams of data, whereas NCS is totally flexible.
. ONC has no general POSIX threads integration which provides
multi-tasking capabilities -- an important feature for
executing more than one remote procedure in parallel. NCS
complies with POSIX.
HP Plans regarding NCS
----------------------
. NCS version 1.5.1 is now available for HP-UX and MPE/ix
platforms, along with Domain systems. This version of
HP is committed to NCS 2.0 on all MPE XL and HP-UX platforms
with our first releases of DCE.
2. OSF SECURITY
--- --------
OSF's Distributed Computing Environment provides security services.
This includes: a) authentication, b) authorization, and c) user
registry.
A) Authentication
--------------
Authentication verifies the identity of the user requesting the service.
In effect, this service proves to the system you are who you say you
are. An analogy might be an HP picture ID proving your identity and
right to enter an HP site.
OSF's distributed Security Service incorporates an authentication
service based on the Kerberos system from MIT's Project Athena.
Kerberos is a trusted service that validates the identity of a user or
service, preventing fraudulent requests.
The OSF Security Service is also integrated with the NCS RPC. NCS
secures communication in the distributed environment by allowing
detection of message corruption. It also guarantees the privacy of
confidential information.
B) Authorization
-------------
After users are authenticated, they must receive authorization to use
resources, such as files. The Authorization facility gives applications
the tools they need to determine whether a user should have access to
resources. It also provides a simple and consistent way to manage
access control information.
This Authorization service includes authorization checks based on the
POSIX conformant access control lists. They provide other
administration tools including a registry database that tracks
authorization information associated with users.
The Authorization service uses the Kerberos format to provide a record
that authenticates a client to a service. The record contains the
client's identity, a time stamp, and an encryption key known to the
client and the service being requested.
C) User Registry
-------------
The User Registry ensures the use of unique user names and passwords
across the network, guarantees the accuracy and consistency of this
information at all sites, and provides security for updates and changes.
It is based on Passwrd Etc from HP and is integrated with Kerberos to
provide security.
Passwrd Etc provides:
. a central repository of user account information, eliminating
the potential for conflicts in logins and passwords.
. consistency of login ID, password, and group affiliations
across different vendor platforms.
. replication and partitioning of User Registry database across
the network, providing high availability and high
performance.
. scalability into the tens of thousands of users and/or
machines, with database management tools to ease the
administration burden.
HP Plans for Security
---------------------
For user registry, HP provides Passwrd Etc. on Domain workstations and
HP-UX platforms with release 8.0. Authentication and Authorization OSF
services are planned for support on MPE/ix and HP-UX workstations with
our first release of DCE.
3. THREADS
-------
The Threads Service includes operations to create and control multiple
threads of execution in a single process and to synchronize access to
global data within an application. The Threads Service is ideally
suited to dealing with multiple clients in client/server-based
applications, because a server process using threads can handle many
clients at the same time.
The Threads Service is based on Concert Multithread Architecture (CMA)
software from Digital and supports the POSIX 1003.4a interface
specification. HP has publicly endorsed the P-threads on CMA to OSF.
The Threads Service is built into a number of the DCE components,
including NCS RPC, Security, Naming, Time and the Distributed File
Services.
HP/UX will support Threads with the first release of DCE. On MPE/ix
kernel threads will be supported with the first release of DCE.
4. OSF's TIME SERVICE
------------------
OSF's Time Service is based on DECdtc and is a software-based service
which synchronizes each computer to a widely-recognized time standard.
This Time Service is required in a distributed application environment
since different distributed components obtain time from clocks on
different computers. A distributed service regulates the system clocks
in a computer network so that they closely match each other, providing
accurate time for distributed applications.
OSF's Time Service software uses Kerberos authentication, and is layer
on NCS RPC.
Status of Time Service
----------------------
DEC is submitting the Time Service technology for OSF DCE which will be
built upon OSF1 with NCS 4.0 and Kerberos. The integration is expected
to be complete by the first release of DCE.
5. Naming
------
OSF's Distributed Naming Service actually consists of two parts; CDS,
or Cell Directory Service and GDS, or Global Directory Service which is
based on X.500.
OSF's Distributed Naming Service provides a single naming model
throughout the distributed environment. This allows users to identify
by name resources such as servers, files, disks, or print queues, and
get access to them without needing to know where they are located in a
network.
The OSF Cell Naming Service, CDS, implemented on top of NCS RPC is
seamlessly integrated with the X.500 global naming system,GDA, and is
integrated with the Security Service. The software supporting the
global naming is based on DIR-X from Siemens and offers full X.500
functionality through the X/Open Directory Service API and through a
standard management interface.
The Naming Service can also create and maintain multiple copies of
critical data, assuring high availability throughout the network despite
hardware failures. Caching of name lookups is provided to speed up
subsequent lookups of the same name.
Finally, like the other OSF DCE services, the Naming Service is fully
scalable, supporting small as well as very large networks of computers
and end users.
Status of the Naming Service
------ -- --- ------ -------
Siemens supplied the DIR-X software for integration into the
OSF DCE offering. DEC supplied the DCE Cell Directory Service, or CDS.
6. The OSF Distributed File System
-------------------------------
The OSF Distributed File System is based on the Andrew File System
(version 4.0) from Transarc which solves the problem of accessing remote
files regardless of where the files reside in the network, which may be
local or wide-area.
The Distributed File Service gives users a uniform name space, file
location transparency, and high availability, via replication.
Essentially, the file system emulates the same behavior as local file
systems, providing access to files anywhere in the network for any user,
with the same filename for all.
This File System is also POSIX compliant, including file access and
sharing semantics (POSIX 1003.1a Portable Operating System Interface)
and access control lists (POSIX 1003.6 Security Interface).
The File System is also based on diskless technology from HP,
accommodating diskless workstations allowing low-cost workstations to
use disks on servers instead of expensive local disks.
Caching is utilized with the OSF Distributed File System, allowing file
sections to be transferred as needed, cached, and stored either on
the local disc or in main memory on the client machine. The benefits
from this include:
. More clients per server since a very large number of concurrent
requests from clients may be handled by a single server since
there is lower overhead on the server.
. Higher-performance for the end user accessing distributed data.
HP Status on AFS
----------------
The Andrew File System (version 4.0) is being supplied by Transarc to
OSF for integration. This is the basis for DCE's DFS, Distributed File
System. HP is providing DFS on their HP/UX platforms in 1993. DFS for
MPE/ix is being investigated.
SUMMARY
-------
In summary, some highlights to remember regarding OSF DCE include:
. Security--OSF DCE security is designed to provide at least
the same security protection provided on a single system, if
not better.
. UNIX User familiarity--OSF DCE relies upon UNIX semantics, where
a minimal amount of training is required to use OSF DCE software
for distributed programming and file management.
. High performance--OSF DCE is designed to address the need for
high performance in a distributed computing environment,
utilizing features such as caching and data streaming.
. Interoperability/Portability--OSF DCE is portable to UNIX and
proprietary systems, and is backed by the OSF whose membership
represents every segment of the worldwide computer community.
This membership includes system vendors such as IBM, DEC,
Microsoft, and HP, as well as independent software vendors, end
users, government agencies, research centers, and universities.
. High availability -- OSF DCE provides high data availability
via caching, data replication, data streaming, data access
methods such as token passing, and error detection and recovery
for the loss of network connection or server computer.
. Standards adherence--OSF provides a set of standards for
enabling distributed computing that developers and system
adminstrators can rely on from all platforms, thus reducing
training and development time and costs.
HP has taken the leadership role in providing technology for OSF DCE and
currently has several key components of OSF DCE technology on the
market. HP is in the best vendor position to provide our customers with
OSF technology today and in the future.
HP is committed to providing high-quality DCE products starting this
year and continuing throughout with DCE developer's kits, Distributed
file systems and DCE end-user services and DME solutions in the future.
Questions and Answers:
---------------------
1. Why did OSF chose AFS over NFS as the winning technology for the
distributed file system component of OSF DCE?
ANSWER:
OSF chose AFS from Transarc because it exceeds the criteria OSF defined
for the distributed file system component of the distributed computing
environment. Specifically, AFS provides these features over and above
NFS functionality:
a. It allows users to address files with the same pathname from
anywhere in the system, regardless of the computer they are
using. It provides transparent access to local and remote
files.
b. AFS hides the complexity of the distributed file system
from system managers. For each cell, which is a configured
collection of servers and clients, only one administrator
is needed to manage, monitor, and maintain the coherent AFS
environment. Online backup tools are provided.
c. Access control mechanisms protect the files and directories by
enforcing uniformity inside a cell. Appropriate security
mechanisms for connections to other configured cells also
are provided.
d. AFS provides high availability of all accessible data
resources. Access to files and directories inside a cell is not
interrupted by single server failures. AFS also makes
replicated units (filesets) of file systems available for read
access.
e. The file server is designed to serve a very large number of
concurrent requests with good performance. Sections of files
are transferred as needed and can be cached on the client
machine.
f. The file server is designed to work in a wide area network
configuration.
2. Is there any guidelines that OSF specifies on why one would go with
LM/X versus PC/NFS for PC integration?
ANSWER:
Although both PC/NFS and LM/X provide similar capabilities (that is,
file and print services), OSF does not believe its endorsement of both
sets of interfaces and protocols is contradictory. PC/NFS provides a
set of protocols used mainly in the workstation market, and LM/X offers
protocols for use mainly by MS-DOS and OS/2 systems. The two markets
can be perceived as two distinct market arenas that require separate
solutions.
The OSF evaluation identified the following functional differences
between LM/X and PC-NFS:
a. The LM/X print capabilities are complete. That is, not only
does LM/X support queuing of files to be printed, it also
supports other administrative capabilities such as listing
the queues, removing jobs from the queues, and starting
and stopping them.
b. The LM/X management capabilities are complete. LM/X
supports a tailorable configuration file (to control
characteristics such as session disconnect timer, process
resource limits, and security mode).
c. The LM/X file service supports remote mounted directories such
as NFS or AFS. In other words, LM/X has access to files that
have been mounted by these file services.
3. Can you describe the process in which the submitted technologies
were selected by OSF for DCE?
ANSWER:
OSF used the Request for Technology (RFT) process as the means to
evaluate the technologies submitted for the Distributed Computing
Environment offering. OSF actively solicits member input in the
preparation of the RFT as well as in the review of the proposals
submitted.
This process rests on four basic processes:
1. Member Special-Interest Groups. Made up of experts from member
companies, SIGs have a powerful voice in the open process,
helping to define the scope and requirements for Requests for
Technology as well as suggesting preliminary evaluation
criteria.
2. Open Technology Acquisition. Through the RFT process, OSF
solicits and evaluates proposals from the worldwide computer
industry as well as educational institutions, government
agencies, and end users. All OSF members, submitters of
technology, and other interested parties are invited to
contribute ideas on technological and market needs as well
as recommend evaluation criteria. At RFT review meetings,
OSF accords non-members who have submitted proposals the same
privileges members enjoy. Taking into consideration the
recommendations of its membership as well as those of non-
member submitters, industry consultants, and standards groups,
OSF selects technology for use in its open computing
environment.
3. Member Meetings. OSF regularly meets with its membership to
exchange ideas on open systems technology. In addition,
members review proposals submitted through the RFT process and
provide input to OSF evaluation teams.
4. Equal and Timely Access to Technologies under Review and
Development. OSF's RFT and development processes provide
members timely access to open systems technologies. Copies of
code still under development, called snapshots, enable members
to evaluate the software, develop their own applications in
parallel with the efforts of OSF, and port the software to
their systems. OSF's snapshot program thus ensures rapid
transfer of technology to the industry.
4. When will HP have DCE Products and on what platforms?
HP will be providing DCE solutions on both HP/UX and MPE/ix.
The first HP/UX products will be available in the fall of 1992.
The first MPE/ix products will be available in the spring of
1993.
These products will consist of the NCS RPC, Timing, Cell
Directory Service, Global Directory Agent {for integration of
CDS with DNS}, Distributed Time Service, Security and Threads.
************************************************************************
If you have additional questions for any portion of this white paper,
please contact:
Network Sales Center
telnet 447-4444
