TigerLogic XDMS for SOA

TigerLogic^® XDMS for SOA
Service Cache, Data Cache and Message Repository

Overview
Web Services and Service Oriented Architecture (SOA) are expected to grow dramatically and place new demands on the existing technical infrastructure within enterprises and organizations. According to Gartner, the worldwide software market for SOA, Web Services and Web 2.0 will grow from $41 billion to $142 billion from 2006 through 2011.

Most Web Services and SOA designs implement services using three tiers:

	Presentation Tier – Interacts with users and calls upon services.

	Middle Tier – Executes business processes, business services and data access services.

	Enterprise Data Tier – Consists of the legacy data sources and packaged applications.

All major software vendors (Microsoft, IBM, Oracle, TIBCO, BEA Systems) provide SOA software platform products. Raining Data’s TigerLogic XDMS complements these major SOA platforms by offering a best of breed XML Data Management Server (XDMS) for caching Web Services and legacy data to improve performance and for storing XML messages for reporting and auditability.

While SOA yields desirable flexibility, the downside is often performance, scalability and auditability problems. As the number of applications in the SOA increases, shared services become the bottleneck, particularly the services that access legacy applications and data stores. Access to enterprise data is where performance problems occur from the concentration of requests through a small number of data access services.

The TigerLogic XDMS service cache supports the caching of Web Service responses -- off-loading the need to constantly access the legacy applications. Additionally, the service cache supports a time-to-live policy, which provides for automatically updating the service cache based on the application requirements. For ease of deployment, the service cache can be exposed as a Web Service through the TigerLogic XDMS built-in Web Server. Existing legacy Web Services can easily be replaced with TigerLogic XDMS Web Services that access the service cache for a cached service response and only access the legacy Web Service to get the initial response or to update a cache response based on the time-to-live policy.

TigerLogic XDMS also supports the ability to cache data from the TigerLogic XDMS native XML database, relational databases, file systems, FTP and HTTP. The caching provides policy-driven read and write access to the data to ensure that the cached data is in-synch with the source data. Data caching can be utilized as a mid-tier data cache, offering a solution to achieve improved system performance, scalability and flexibility by moving the required data as close to the services as possible and mitigating contention on back-end systems.

Additionally, as more services are added, it becomes more difficult to capture all the information exchanges. A high performance central repository that stores and indexes all XML messages is needed for reporting and regulatory requirements.

TigerLogic XDMS for SOA Architecture
TigerLogic XDMS for SOA supports standards-based Web Services, a Java API and .NET API, which can be used to plug the TigerLogic XDMS into an existing Web Services Architecture. TigerLogic XDMS for SOA can be used as a service cache, a data cache and/or a message repository as illustrated in Figure 1 below.

SOA Architecture

Figure 1: TigerLogic XDMS Fits in the Middle Tier of Existing SOA or Web Services Architecture

Service Cache and Data Cache
The TigerLogic XDMS service cache stores Web Service responses with specified time-to-live policies (e.g., update if older than fifteen minutes, older than 24 hours). The application now goes to the cached service rather than the legacy Web Service.

The TigerLogic XDMS data cache stores legacy data at the middle tier with specified refresh policies (e.g., update every fifteen minutes, update at end of day, update when legacy data changes). The middle tier application now goes to the cached data rather than the legacy data source. The TigerLogic data cache can also be configured to allow write-through to the legacy system as well as to store the cache in-memory (versus on disk). Caching the Web Service responses and/or the legacy data improves performance and reduces the load on the legacy systems.

TigerLogic XDMS comes with an easy-to-use Administration Console that allows you to select Web Services with time-to-live polices for the purpose of creating a service cache and selecting legacy data sources, refresh policies and write-through policies for the purpose of creating a data cache. See Figure 2 below.

Figure 2: TigerLogic XDMS Administration Console

Message Repository
The TigerLogic XDMS can also be utilized as an XML message repository for capturing and indexing messages in their native XML format. The XML message repository allows managers to profile messages, payloads and transactions for auditing and other purposes such as regulatory requirements.

SOA transactions may be complex and involve many Web Services over a period of time. For example, the data associated with a single SOA transaction might easily total 1 MB, involve multiple Web Services, involve multiple updates and be heavily nested. TigerLogic XDMS provides a high performance XML data management system that can handle high volume inserts, updates and searches of the XML messages. Additionally, if XML messages have evolving XML schemas, the TigerLogic XDMS is designed to handle multiple versions of the schemas.

TigerLogic XDMS Technology
The TigerLogic XDMS provides a self-evolving, high performance data management system and is comprised of an XML database and an XQuery engine. TigerLogic XDMS has a multi-schema engine, which can manage multiple, evolving schemas on the same collection. It provides high performance data management and includes a 64 GB in-memory data cache.

The TigerLogic XML database has all of the functionality required of an enterprise database, including:

		XA Transaction Compliance
		Security
		Replication
		HA Clustering

The TigerLogic XDMS XQuery engine provides access to the TigerLogic XDMS XML database as well as other data sources, including:

		Relational Databases (through JDBC)
		Web Services
		FTP Sites
		File Systems
		Java Objects
		Web Pages

TigerLogic XQuery is compiled into byte code for high performance and can also be deployed as XQuery stored procedures. TigerLogic XQuery has an Application Programming Interface (API) for Java, .NET (ADO), and Web Services (SOAP). See Figure 3 below.

TigerLogic XML Data Management Server Architecture