SIF Association

This blog is run by the staff of the SIF (Schools/Systems Interoperability Framework) Association for the use of it's members and the general educational community.

It is specifically designed for those who are interested in understanding what SIF is about, where the standard is going and how Schools, Districts and State Educational Authorities will benefit.



Tuesday, November 12, 2013

SIF 3.0 Infrastructure (Very) High Level Overview

The following is taken from the Read This First (RTF) document, which forms the introduction to the SIF 3.0 Infrastructure release collateral.  For those interested in exploring the new SIF release in further detail, the RTF is probably the best place to begin.  It is located at:

     https://www.sifassociation.org/Specification/Pages/Infrastructure_3_0.aspx

 

Q. What exactly IS the SIF 3.0 Infrastructure?

SIF 3.0 is the latest release of an open standard infrastructure which began 15 years ago as the product neutral interface of an existing commercial message broker. This release brings SIF into the modern era by leveraging a REST based approach to data exchange. The key contribution the SIF 3.0 release makes is to define, coordinate and standardize the ways in which a RESTful educational service can be accessed securely, robustly, and in real time by multiple RESTful clients.

SIF 3.0 infrastructure is the first infrastructure release to be completely separate from the data model defining the payloads it carries, which means it can be used to support many different data models in many different locales. For example while the SIF US data model is based on CEDS, this is not explicitly reflected in the SIF 3.0 Infrastructure documentation.

Q. Why was a major release of the infrastructure needed at this time?

The SIF 2.x infrastructure was initially architected more than a decade ago, and the SIF 3.0 infrastructure introduces a wide range of needed new functionality. Of particular note are three ground-breaking design advances which satisfy long standing requests from SIF 2.x developers and implementers. They are summarized below. 

1. Make the SIF Infrastructure independent of the SIF Data Model

All current data model dependencies of the earlier release have been removed.  As a result, the SIF 3.0 infrastructure can carry SIF object data from any locale (US, UK, AU), or for that matter data in conformance with other major data standards, without change.

 

2. Offer alternatives and extensions to the required monolithic middleware component (ZIS)

This issue has been addressed on two fronts. 

First, the ZIS-provided message broker functionality has been broken up into a set of multiple, separately implementable Infrastructure Services.  These were designed to individually map to common industry technologies such as “Enterprise Service Bus (ESB)”, “Queue Manager” and “Service Registry”.  The SIF 3.0 Brokered Environment middleware can still be implemented by a single, monolithic component, but it no longer has to be. 

Second, the new SIF 3.0 architecture makes it possible to construct and deploy SIF-compliant solutions in a Direct Environment without utilizing any middleware at all!  This new SIF infrastructure alternative offers clients a standardized subset of the functionality available from the Brokered Environment, which means that these clients can be deployed into middleware-centric solutions with no recoding or reintegration efforts required.

 

3. Support industry standard transport technologies

The SIF 3.0 infrastructure documentation describes the service framework and associated core services and utilities in a platform neutral manner.  As a result, it can be mapped to any modern transport running over HTTP/S.

The defined platform mapping of the SIF 3.0 infrastructure is REST.  The SIF 3.0 infrastructure includes paged reads, synchronous IO and support for the primary REST resource design patterns.  XQuery scripts and dynamic Query URL parameters are both supported in SIF 3.0 replacing the earlier SIF-specific (and less powerful) Query and Extended Query functionality.

These and other changes allow SIF 3.0 solutions to be deployed in the Data Center of an educational organization using the identical technologies that are already present and known to IT personnel.  It also makes it easier for vendors to staff SIF-related projects as both the REST infrastructure technology and to a lesser extent.

SIF 3.0.  Everything you want in a SIF Infrastructure.