Administration of the XML Data Archiving
Service
Purpose
The XML Data
Archiving Service (XML DAS) is a new technology that was created especially for data archiving
in the JAVA stack and
XML-oriented ABAP
archiving objects. XML DAS is one of the main components needed for
XML-based Data
Archiving, and is used by both ABAP and JAVA applications. It is part of a
standard SAP J2EE Engine installation. Before you can begin XML-based
archiving you must set up the different components involved and configure your
systems. For this purpose, the XML DAS comes with an administration tool
called the XML
DAS Administration. Together with Archive
Administration (transaction SARA) in the ABAP stack, this is the most important tool for an
archive administrator.
Implementation Considerations
To be able to use the XML DAS and the XML DAS Administration, you must implement the following steps:
...
1. Install an appropriate version of the SAP J2EE Engine (XML DAS is available as of Release 6.40). This will create the following for XML DAS:
¡ The application sap.com/tc/TechSrv/XML_DAS, running in the Web Container
¡ The database pool alias SAP/BC_XMLA for sap.com/tc/TechSrv/XML_DAS
¡ Initial database content such as entries in table BC_XMLA_RESTYPES
2. Set up your storage system or systems:
¡ Make available one or more WebDAV or file systems for storing archived data
It is recommended that you use a WebDAV system, because one of the important advantages is that the WebDAV protocol stipulates a reliable synchronous response to atomic write requests used for archiving resources.
¡
In case of
file systems, create one or several directories as needed. If you create
several adhere to the restrictions described under Define Archive
Stores. Make sure each directory (acting as archive store root) is
accessible to all servers of the SAP J2EE Engine hosting XML DAS. The
Operating System user employed for Windows systems is SAPService<sid>
and for UNIX/Solaris systems <sid>adm. Therefore, each directory needs
to have the appropriate access privileges. See also:
Operating System
Security.
To prevent unauthorized access or harmful alteration or deletion of resources or directories in the file system, give the appropriate access privileges only to SAPService<sid> or <sid>adm, respectively.
Do not manually create or delete directories or files once the archive store root directory is fixed.
3. Set up the connection between the application system or systems and the SAP J2EE Engine running XML DAS.
¡ You can use any of the HTTP authentication methods supported by the participating client system and the SAP J2EE Engine, such as Basic Authentication, Basic Authentication with SSL (HTTPS), or Client Certification.
¡ If you are using HTTPS, both the client system and the J2EE Engine must be configured for SSL support. For more information see Configuring the Use of SSL on the SAP J2EE Engine.
In addition, you must perform several customizing tasks using the XML DAS Administration. These tasks are described in detail in the following documentation.
Before you start XML-based data archiving we
recommend that you familiarize yourself with the concepts of data archiving in
general and read the corresponding documentation for
ADK-based Data
Archiving and
XML-based Data
Archiving.
Integration
XML-based data archiving involves two systems that are logically, and usually also physically, separate. One is the application system, whose database has grown too large and therefore needs to archive its data. The other system is the archiving system. XML DAS is part of the latter, the archiving system, and runs within the SAP J2EE Engine. This means that the “store part” of the archiving processes primarily take place on the JAVA stack of an SAP Web Application Server. The figure below shows how the XML Data Archiving Service interacts with the different components involved in XML-based data archiving.
During XML-based archiving the meta data and the property indexes used for value-based searches of archived data are stored in the database of the SAP J2EE Engine. The actual data that has been archived is stored in a storage system, which is connected to the SAP J2EE Engine via the WebDAV protocol. It is also possible to use a file system instead of, or in addition to, a WebDAV system.
This system has to be set up in such a way that it is accessible from all servers of the SAP J2EE Engine. To configure your file or WebDAV system for XML-based archiving, you use the XML DAS Administration, shown in the figure below. These settings are essential for XML-based data archiving and span across application systems. Therefore, as we mentioned above, the XML DAS Administration is one of the most important tools for an archive administrator.
There are two ways you can reach the XML DAS Administration:
·
From
Archive Administration (transaction SARA) enter your XML archiving
object and choose Customizing. From the
XML Basis
Customizing menu choose XML DAS Administration.
· As a browser application using the following address:
http://<Host of SAP J2EE Engine>:<HTTP port>/DataArchivingService/DAS
To successfully connect you need a SAP Web AS user that is assigned to the security role XMLDASSecurity Role.
Example
http://localhost:50000/DataArchivingService/DAS
If you do not have the ABAP stack of the SAP Web AS installed, you can only reach the XML DAS Administration as a browser application.
Features
After you have set up your systems you must peform the following Customizing tasks before you can begin XML-based archiving. You perform these functions using the XML DAS Administration, and in the following order:
...
1. Define and test the archive stores:
¡ The concept of an archive store is used to refer to a location (WebDAV collection or file system directory) within a storage system. Using the XML DAS Administration, you must first define archive stores to be able to test their availability.
¡ In case of WebDAV servers accessed via proxies, register the proxy for each archive store.
2. Synchronize the home paths between application systems and XML DAS:
¡ The XML DAS Connector of an application system provides a function to propagate new home paths to the XML DAS. Make sure that this function is executed so that XML DAS synchronizes the "known" home paths with new ones required by the applications.
SAP recommends that, if possible, you perform this necessary step from within the application system. This is because only here application-specific customizing can be taken into account.
In
case of an ABAP application, use transaction SARA (see the Synchronization of Home Paths section under
Basis
Customizing: XML Archiving) instead of the XML DAS Administration. This
function determines and synchronizes home paths for all existing XML archiving
objects, using reserved key words.
Synchronizing via the XML DAS Administration is mainly recommended for test purposes.
3. Assign home paths to archive stores:
¡ Using the XML DAS Administration, you must assign an archive store to every home collection or application collection you want to use for archving.
In addition the XML DAS Administration offers the following features for packing and unpacking resources: