Friends, Great inputs… Per
discussion with the SOA COP project, Dov’s earlier comment, and a running
conversation Brad and I have been having, I think we should also emphasize the
need
to include a shared “lab” as
part of the infrastructure. I defer to Brad’s description of the concept.
Another thought…. Should we
emphasize that SOA is at least as much about B2B as P2B?
Best, Chris
From: Vijay Raghavan
-Towerstrides [mailto:vijay.raghavan@xxxxxxxxxxxxxxxx]
Sent: Friday, February 09, 2007
1:39 AM
To: 'Rollins, John'; 'Dov J.
Levy'; RFarrow@xxxxxxxxxxxxxx; bcox@xxxxxxxxxxxxxxx
Cc: pgfsoa-infra@xxxxxxxxxxxxxx;
Chris.Gunderson@xxxxxxxxx
Subject: PGFSOA-Infrastructure-
Key messages
Team
I took the liberty of continuing this
thread instead of posting new. Please advice if it has to be new.
John/Dov/Brad I had the pleasure of going
through each of your analysis and comments.
I would like to add or reiterate some of
the key messages here. As always please feel free to comment or advice.
1) Network Infrastructure with focus on
Transport technologies: We all agree one of the enablers for SOA is Web services
and one of the critical components of SOA Governance is SLA.
How Web Services affect Network?
Renewed IT investments are driven by
increasing demands for more efficient communications and information sharing
across disparate agency networks. Increasing volumes of data required for
decision support results in progressively more complex data management
environments. Web services, which use distributed software programs and applets
that form building blocks for application development, operate across
geographically dispersed computing platforms. The need to reference multiple
applications physically residing in geographically distributed locations
creates additional traffic and service management challenges. Controlling large
quantities of intersystem traffic requires robust, flexible networks that
provide high levels of network performance (i.e., low latency and high
throughput) to enable a high-quality user experience
Why SLA
(High Availability) affect Network
Agencies
increasingly focus on data availability and protection as they implement
solutions for continuity of operations (COOP) and disaster recovery (DR). Data
transport between primary and backup locations, often separated by hundreds or
thousands of miles, is integral to effective COOP and DR strategies. As data
backup needs increase, agencies must weigh the risk versus importance of the
data and balance this by providing an affordable, secure and highly adaptable
network solution. Increased user demands on agency networks, coupled with the growth
in latency-intolerant and bandwidth-hungry applications, often exceed the
capabilities of existing network infrastructure.
Disjointed network architecture with multiple transport technologies managed by
a mix of in-house and third parties contribute to the limited interoperability
of networks and applications. Taken together, these factors drive network
planners to seek flexible, adaptable and manageable WAN solutions. These WAN
solutions include private optical networks and managed wavelength services
tailored to the networking requirements and cost constraints of government
agency networks.
2)
Portal Infrastructure: To implement a service-oriented architecture (SOA),
companies must consider what steps and technologies are involved. Portals
represent a logical first step in the process.
A portal
can clarify the sometimes confusing SOA concept for an organization’s IT
staff and end users. An enterprise portal project pulls together the disparate
groups involved in cross-enterprise technology projects. No other technology is
more tangible than a portal, and IT professionals and users can relate to it.
Portal products have leveraged service-oriented concepts since 1998, so they
provide a natural approach to SOA. It leverages Web services extensively.
• It leverages portlets, which consume services or communicate to provide
orchestrated flows and on-the-glass composite applications.
3) Meta
Data Management: Although promising as a new method for building applications,
SOA will fail if long-standing data quality, data redundancy and semantic
inconsistency issues are not addressed. Unless
Organizations
take a disciplined approach toward enterprise wide information management; the
SOA method of development may become fraught with highly redundant and
inconsistent data stores and data integration applications, which is no
different than today's reality in most large enterprises or Gov. Organizations.
Complex or conflicting sources, inconsistent semantics and poor quality data
(previously hidden and protected in tightly coupled systems) are suddenly
exposed during service composition, creating confusion as multiple developers
try to achieve efficiency and reuse.
More to
follow.
Thanks
Vijay
From: Rollins, John [mailto:jrolli01@xxxxxxxxxx]
Sent: Thursday, February 08, 2007
5:56 PM
To: Dov J. Levy;
RFarrow@xxxxxxxxxxxxxx; bcox@xxxxxxxxxxxxxxx;
vijay.raghavan@xxxxxxxxxxxxxxxx; Rollins, John
Cc: pgfsoa-infra@xxxxxxxxxxxxxx
Subject: Key messages
All,
I
thought I'd take a shot at a few key SOA Infrastructure messages. No pride of
ownership so feel free to comment.
1)
The same principles that applied in managing "pre-SOA"
infrastructures also apply here. The platform technologies such as the
networks, protocols, OS's, storage, computers, etc. are essentially the same.
The SOA Infrastructure, the subsequent services and applications are still
beholden to that platform and must be managed in a similar way. Therefore, the
same approaches for network/enterprise management are relevant, i.e. I have to
make systems available, secure, monitorable, accountable, etc.
So
don't throw away your enterprise management techniques.
2)
In fact, SOA makes enterprise management a little harder. At its essence it
encourages ad-hoc connections across the infrastructure. Consumers may use
services in ways never conceived, and of course with unreasonable expectations.
This can stress parts of the infrastructure that were architected with a
"known-connection" mindset. Therefore, you must manage the
infrastructure to ensure service SLA
compliance, balanced infrastructure load, and priority resolution to accomplish
mission goals. New tools that understand the SOA platform should be part of the
SOA portfolio.
Greater
freedom in employing services to solve problems requires greater management of
the infrastructure.
3)
Policies need to be declarative, centralized, and executable. Declarative:
Human readable and represented as data, not code, so that they can be
understood and changed. Centralized: From an operator perspective, he/she must
be able to access the relevant policies. These policies may be federated across
different stores, but the operator should have one access point. Executable:
Policy Enforcement Engines, wherever they may live in the enterprise, must be
able to execute the policies within the context that they are executed.
A
self-organizing set of services requires accessible, flexible, changeable
management policies.
4)
The communications infrastructure used to invoke services, send messages, etc.
must support flexible message exchange patterns. a) Lengthy request-response
transactions within a distributed environment can cause chaos. The
infrastructure should provide a range of invocation patterns that enable
clients to experience synchronous operations, while the infrastructure
implements asynchronous behavior. b) The infrastructure should allow service
locations to be hidden. The client of a service should not be bound to its
location; the infrastructure should take care of the routing and QoS. c)
Point-to-point messaging often used by publish and subscribe components -
especially with centralized broker scenarios - can cause immense performance
problems. Alternatives that allow either federation of the publication or
multicast of the information should be available.
The
messaging plumbing is the key component to enabling services - you can't use
what you can't get to.
5)
Service profiles should not only state what consumers expect of the service,
but also what the service expects of the infrastructure. A service can't meet
its SLA's if it expects performance, QoS, etc.
that can't be delivered by the infrastructure. These service profile statements
could be inputs to management policies.
There's
no sense offering services that can't meet their SLA's.
Thanks,
John