Conclusion and Outlook

  The paper described a case study for the dynamic management and monitoring of QoS parameters and SLAs based on JDMK and ARM. We have discussed our implementation concept with flexible and extensible agents which operate at the customer site. Our work was motivated by the increasing demand for scalable and reliable solutions which allow the extension of management agents at runtime. The experiences gained in this project allowed an evaluation of the applicability of JDMK for managing large-scale enterprise networks and can be summarized as follows: The development environment permits rapid prototyping and is easy to use; the transfer of lightweight applications (implemented as JavaBeans) to management agents at runtime works very well: JDMK supports both push and pull models and enables agents to acquire additional functionality, thus improving their (albeit limited) autonomy. JDMK is best described as a development framework for Java-based Management by Delegation. At its current stage, JDMK is a powerful toolkit for the development of management agents that can be accessed and modified through several different communication mechanisms.

The usability of management systems - especially in an enterprise-wide context - depends to a high degree on the security features of the underlying middleware. However, the JDMK security mechanisms are yet unsatisfactory because the different mechanisms of the underlying communication protocols/infrastructures have not yet been integrated into a common security architecture. It therefore depends on the type of the underlying protocol whether e.g., encryption is available and how access control is handled. Another critical issue is the absence of services to obtain meta-information on the deployed agents (like a ``global'' interface repository and naming services): The services to obtain information regarding the whole set of agents in a JDMK environment lack scalability because they can only be applied to a single Core Management Framework, thus preventing a global view on the agents.

The experiences of the project further allowed an evaluation of how ARM can be used for the monitoring of service levels of client/server applications. As the benefits of ARM outweigh the disadvantages by far there is hope that it will increasingly be adopted by vendors. Recently the CMG has released a preliminary version of ARM 3.0 SDK for public review (for a short overview see [#!john:99!#]). The most important topic of this release is the new Java binding. With this feature Java programs can use the ARM API directly and the indirection via Java Native Interface is not necessary any longer. However, until now the formal specification of ARM 3.0 is not available. Growing customer demand for applications ready for management will lead to a growing number of instrumented applications. A number of management tool vendors already offer solutions that implement the ARM API.