Data Replication Products 

The ATCCIS concept of replication is explained in the right-side note.

ATCCIS Baseline 2.0 includes several Data Replication products. Most of them are related to the ATCCIS Replication Mechanism (ARM):

  WP 14-3 ATCCIS Replication Mechanism (ARM) Consolidated Specification, edition 5.0. It has a main document file and an PDF file capturing the Erwin model.

  The purpose of this paper is to define the specification of the ARM, incorporating background and concepts from WP 14-1 and WP 14-2, and to provide the basis for guidance for implementation teams (e.g., in WP 14-4). For ATCCIS 2000 the paper is transformed into a consolidated specification that can be used as Baseline 2.0 document.

  WP 14-6 ARM Management Data Fill, edition 5.0. It consist of one main body file, an annex B file, and annex C file and an annex D file.

  The purpose of this paper is to provide a detailed description of, and reference to, a database (known as a data fill) of ARM management data. This database is provided separately as a Microsoft Access 2000™ file in WP 5-5 AIRD, and the SQL scripts are provided in Annex B.
The document also describes the All Data Contract whose replication domain is the entire LC2IEDM.

The ATCCIS End of Phase Documents have one Data Replication WP:

  ARM Open Issues Library, edition 5.0. As part of WP 14-3, this is one main document supported by several folders containing the ARM Change Proposals.

  CPs submitted by Nations to improve ARM Specification but not incorporated in Phase 5. For future consideration. This is a library of Change Proposals (CPs) in Word format supported by an Excel Spreadsheet that tracks progress.

You may wish to read these WPs in order to get a concise view of ATCCIS:

  ATCCIS Phase V Final Report, edition 5.0, consisting of one file.

 WP 5-7 Overview of the LC2IEDM, edition 5.0, consisting of one file. 

 WP 3-6 ATCCIS Key Management, edition 5.0, consisting of one file.

  WP 3-1 DATA Naming Procedures for the LC2IEDM Data Model, edition 5.0, consisting of one file.

  WP 31-1 ATCCIS Filtering Proposals, draft 5.0, consisting of one file.

  WP 18-2 Flexible contracting, draft 5.0, consisting of one file.

Use the Document Navigator to find quickly the documents relevant to you.

Replication

   The ATCCIS architecture has characterised ATCCIS-conformant systems as transaction processing systems based on a partitioned, partially replicated database.

   This requires agreement on the structure of the data to be exchanged and on the method for how these data are to be exchanged.  

   The structure for the operational data subject to exchange for ATCCIS-conformant systems is the so-called ATCCIS Data Exchange Schema (ADES), currently chosen to be the LC2IEDM, in previous ATCCIS phases called the ATCCIS Battlefield Generic Hub Data Model.  

   The method of exchange comprises the set of protocols and other specifications provided in WP 14-3 that together characterise the ARM.  

   The aim of the ARM is to preserve consistency of the databases in terms of the meaning and relationships of data being exchanged.

   Replication concepts are modelled in the ARM Management Data Model that structures management data information pertinent to managing the replication of information between users. The Management Data Model has been modelled with Idef1X.

   Links to IDEF1X:

AllFusion Erwin

FIPS PUB 184

Idef1X

Data Replication Activities (Phase V)

During the ATCCIS Phase V, the Architects Working Group met 8 times and  produced the products contained in the Data Replication Working Papers above mentioned. Conclusions on the ARM could be:

  The ARM is now a solid and well-specified replication mechanism that has been implemented and proven a number of times.  Also it has attracted the interest of industry, and commercial implementations are available.  A word of caution is however necessary.  The ARM is yet to be tested in a demanding multi-national environment on a network of many nodes. 

  The aspiration to incorporate dynamic contracting into replication remains unfulfilled.  Two papers were produced to consider this issue and future work must decide an appropriate response to this lively issue.

The ATCCIS Heads of Delegation (HoDs) empowered a task force to develop a limited set of filter specifications.  The HoDs provided specific guidance to define filter types that could be applied to a single Information Exchange Contract (IEC) replicating an entire database.

The scope of the work was limited by the guidelines below:

  Examine area, echelon, hostility, and time as candidate filter types,

  Assume that the only allowed replication contract type is All Data Contract,

  Capture the operational justification for filtering within the context of the LC2IEDM Edition 2.0 data structure,

  Develop exact statements of filter specifications, and

  Identify technical implementation constraints whenever possible.

The task force produced a set of specifications for five types of filters: area, time, ORBAT, combination of area and time, and combination of area and ORBAT.  The hostility filter was removed from consideration following operational advice.  The ORBAT filter type that is based on organisational relationships replaced the echelon filter type that was assumed to be based on size.

Whether filter specifications should be carried forward is a decision that depends more on the concepts for employing automated systems for information exchange than on technical issues in filtering. In any case, the current filter specifications produced in the context of LC2IEDM Version 2 would need to be updated to accommodate the next version, LC2IEDM Version 5, as users convert to this new schema.

Layers

   The  Replication Manager (REPMAN) Layer and the Transfer Facility Manager (TFMAN) Layer interface with the Application Layer and the Transfer Facility, which are defined as “ARM Layers”.    

    The REPMAN Layer’s main task is to take care of synchronisation issues, basically determining what needs to be synchronised with the connected databases and how.  Another task is to generate messages by and while keeping track of states of the connected databases.  The REPMAN Layer does so for both operational data (ADES data) and management data (data in the ARM Management Database).  Its other tasks are transaction management and providing some level of assured delivery.

    The TFMAN Layer’s task is to provide a means of communication between any two nodes.  To do so, it has the availability of a number of Transfer Facilities. 

    The Transfer Facility Layer provides an abstraction of network protocols (such as TCP/IP, X400) and/or network services (such as compression, encryption, error correction).

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Remarks

Formats remark:

  All the hyperlinks point to the Adobe Acrobat version of each document. In order to get the Microsoft Word^@, Microsoft Access 98^@, Microsoft Excel^@ or Erwin 3.5.2^@ you will need to navigate through the Web Site (using for example MS Explorer^@ or any FTP client).  

  Copyrights are detailed in Home Page. 

 Contracting

  A replication contract is the means for controlling (selective) replication of database changes.  

  A contract is established between two replication nodes, designated as Data Provider (DP) and Data Receiver (DR).  In the contract, the DP and the DR agree that the DP will provide the DR with all data that satisfies the conditions of the contract.