The XML Data Archiving Service (XML DAS) is a 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 Application Server Java (AS Java) 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. This is one of the most important tools for an archive administrator in both the Java and ABAP environment.
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 AS Java. This will create the following for XML DAS:
○ The applications sap.com/tc/TechSrv/XML_DAS and sap.com/tc/archtech/xmldasinitservice running in the Web Container
The servlet /archtech/xmldasinitservice is responsible for creating User Management Engine (UME) roles and for initialising the MBeans.
○ The database pool alias SAP/BC_XMLA for sap.com/tc/TechSrv/XML_DAS
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.
○ Create a new or choose an empty directory (file system) or collection (WebDAV) as the root node for your archiving sessions.
○ In case of file systems, make sure each directory (acting as archive store root) is accessible to all servers of the AS Java 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. Create a user that is assigned to the Administrator role and call the XML DAS Administration from within NWA. For more information see the documentation on User 2 and 3 under Creating Users and Assigning Roles.
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.
XML-based archiving involves three systems that are logically, and sometimes also physically, separate. One is the application system (for example AS ABAP, or AS Java) that needs to archive its data to reduce the size of its database or for legal compliance purposes. The second system is the archiving system. XML DAS is part of this archiving system, and runs within the AS Java. This means that the “store part” of the archiving processes primarily take place on the JAVA stack of an SAP NetWeaver Application Server. The third system is the one running the SAP NetWeaver Administrator (NWA), which contains the Java Archiving Cockpit and the XML DAS Administration described here. For a visual representation of how the XML DAS Administration interacts with the different elements see Administration Functions for Information Lifecycle Management.
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 AS Java where the XML DAS is running. The actual data that has been archived is stored in a storage system, which is connected to the AS Java of the XML DAS via the WebDAV protocol. It is also possible to use a file system instead of, or in addition to, a WebDAV system.
This storage or file system has to be set up in such a way that it is accessible from all servers of the AS Java. To configure your file or WebDAV system for XML-based archiving, you use the XML DAS Administration. 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 archiving administrator.
The XML DAS Administration is part of the NWA and can be reached in the following manners:
● Choose Operations Management → Data and Databases and then choose XML DAS Administration
After you have set up your systems you must perform the following Customizing tasks before you can begin XML-based archiving. You perform these functions using the XML DAS Administration:
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:
Using XML DAS Administration to synchronize home paths is recommended only for test purposes! 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.
○ Even though this function is available in the XML DAS Administration, the XML DAS Connector of every 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.
■ 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.
■ In case of a Java application, the home paths are synchronized automatically, when the Java Archiving Cockpit is started.
3. Assign home paths to archive stores:
○ Using the XML DAS Administration, you must assign an archive store to the appropriate places in the archive hierarchy, to be able to actually store the data in the storage system of your choice.
In addition the XML DAS Administration offers the following features for packing and unpacking resources: