Enforcement of server commitments and system global constraints in SOA-based systems

Abstract

Under Service oriented architecture (SOA), a systemsuch as an enterprise-consists of multiple heterogeneous servers (service providers), which may be distributed over a wide area of network, and may be managed under different administrative domains. One of the goals of this work is to enable the system as a whole (i.e., the enterprise) to impose global constraints on the interactive behavior of the various heterogeneous servers.Moreover, individual servers typically make explicit or implicit commitments to their clients regarding the services they provide. Such commitments may include such things as privacy policies, and SLAs, as well as run-time promises to reserve certain merchandise for a specified time period. But the SOA methodology provides no guarantees to clients that the commitment made by a given server would actually be satisfied. Our second goal is to enforce certain types of commitments made by servers, provided that these commitments conform to the global constraints imposed by the system at large.Our technique employs LGI-based middleware to enforce stateful policies, and does not require any change of the conventional SOAP-based protocol, the UDDI server, or the programs employed by servers and their clients.

A collaborative framework for enforcing server commitments, and for regulating server interactive behavior in SOA-based systems

“…This work is a significant extension of our previous one [11] in the following aspects. First, we introduce and implement the concept of using policies to specify how trusted components collaborate to establish a network of LGI controllers to enforce server commitments.…”

“…First, we introduce and implement the concept of using policies to specify how trusted components collaborate to establish a network of LGI controllers to enforce server commitments. Second, we show how LGI controllers collaborate with the trusted components mentioned above to regulate server interactive behavior which also includes serverserver interaction, a common interaction in SOA systems which is not considered in [11]. In this interaction, the two controllers of the two involved servers dual-mediate messages exchanged between a server and its peer server.…”

Dependable Management of Untrusted Distributed Systems

“…We already did some preliminary work [18] on one approach to this problem, which requires a change in the LGI middleware, and has certain drawbacks. Another possible approach for solving this important problem is based on the following observation 6 : If we can apply GBM to systems based on Service Oriented Architecture (SOA) principles, then we can apply it also to any SOA-enabled legacy systems-enabled through the use of facade patterns that exposes the legacy system capabilities through SOA-based interfaces.…”

FIT for SOA? Introducing the F.I.T.-Metric to Optimize the Availability of Service Oriented Architectures

“…Metrics to measure granularity, complexity and reuse [15,35,36], performance [5,13] and QoS [28,31] of SOAbased services also rely on design-time data. Most work on operation and optimization has been done on how to handle service level agreements primarily based on design-time data: how to formally describe them [19,34,39,40], technically implement, test and enforce them [4,10,15,17,18,23,25,26,32,33,42,44,45] or how to monitor them [2,20,21]. Contributions available on SLA design deal with isolated approaches: Sauvé et al [38] and Marques et al [27] are in favor of deriving the service level targets directly from the business impact of the given service (i.e.…”