We have already gained some experience using our tools in several different environments. A summary of our main projects is shown in table 1. The type of the object system, its operating system, the application which had to be analyzed and the project partner are listed. Most projects were performed together with other groups in our Institute for Mathematical Machines and Data processing (IMMD). But there are also some projects with external industrial users: IBM European Networking Center (ENC) in Heidelberg, IBM Research Laboratory in Zurich and Siemens AG in Erlangen and Munich. SIMPLE is now installed at 12 institutions in 5 countries.
Experiences gained during these projects showed that the design principles of ZM4 and SIMPLE are sound. Practical use of ZM4/SIMPLE confirmed that the hardware monitor system ZM4 can easily be adapted to arbitrary object systems and that SIMPLE is a highly flexible and comfortable tool with which all kinds of event traces can be evaluated. Using the TDL/POET interface makes it possible to access event traces of any format and origin by simply giving a TDL description of the trace. The concept of object-independence proved to be a big step forward. Tool environments such as ZM4/SIMPLE provide a valuable aid to designers and users of parallel and distributed systems.
In the title of this article we asked: Is an Implementation of Object-Independent Event Trace Monitoring and Analysis Systems Possible? We hope we could convince the reader that the answer to this question is YES! Not only is it possible, but such a system can be designed and implemented in an efficient, powerful, and object-independent way.
A final word on standardization: we feel that standardization of the physical event trace format is not the right approach. No standard format can be flexible enough to represent all possible event trace formats unless format information is included in the trace - this being somewhat inconvenient. Furthermore, there is a great variety of existing (hardware) monitors which cannot produce a standardized format. Therefore, many conversion programs would have to be implemented. The TDL/POET interface shows that a generalized access method for arbitrary event traces works well without requiring standardized physical formats. We therefore plead for standardizing the event trace access interface instead of standardizing the trace format.