Minutes of the meeting of SAGA-RG held at OGF21, oct 17, 2007, 15:15-16:45 notes: Shantenu Jha, Thilo Kielmann agenda: 1. IPR 2. Agenda bashing 3. Java binding for the CORE spec Thilo Kielmann opens the session, explains the IPR rules and hands out the signup sheet It is agreed to begin the session with a short report-out from the "future of DRMAA" session. Here, Dan Templeton reports about the plans to prepare a next DRMAA version as another SAGA package. Both the SAGA and DRMAA groups want to cooperate on this issue. Java binding: Thilo Kielmann is presenting important aspects of the Java binding, as it is currently being developed by his group. fundamental decisions: - design for Java 1.5 - for application portability across multiple implementations, a mechanism like C++ header files is desirable. for this purpose, the language binding presents all SAGA interfaces and classes as interfaces, accompanied by factory classes. These interfaces and classes will have to be used by all implementations, acting like header files. Flags being used, e.g. for file read/write/create operations. ----- The current soluton is based on enumerations. The participants doubt that this solution is ideal. Use of these enumerations is complex due to the method interface of the object. Also, these enums are converted to integers for the operations (e.g., file read); this violates type safety. The participant discuss alternatives for modeling such flags. They favour two options: a) a pure integer-based solution without type safety, but with an easy to use interface and predefined constants (powers of two) b) a real object that never gets casted to integers Proposals for both versions shall be made and posted to the mailing list for comparison and for adopting one of these two approaches. timeout values: -------------- numeric constants such as "nowait" and "waitforever" shall be used instead of 0 and -1 Buffers: ------- it is suggested to check whether the NIO bytebuffer could be used instead of a from-scratch buffer files: ----- SAGA files are POSIX style the Java binding is using exceptions instead of the POSIX error codes The current file implementation is inspired by random files. inputstream and outputstream shall be layered on top of this. tasks: ----- this interface (group) seemingly needs more attention it is suggested to check whether future objects from the concurrency library could be used. the RVTask looks very much like a future the asymmetry between run() and waittask() should be resolved optional parameters: ------------------- it is suggested to add methods (via overloading) that do not have the last parameter for those methods with optional parameters in the SAGA CORE spec. maybe the varargs mechanism might help (whatever becomes easier to use) implicit sessions: ----------------- in SAGA, the default session is used unless specified differently. this means that the factories need additional methods without session parameters. RPC package: ----------- esp here, the varargs package might be useful CPI, adaptor interface: ---------------------- The audience suggests to add an SPI (service provider interface) as part of the Java language binding (currently called CPI in the JavaGAT) This could allow for a standardized adaptor interface, and thus adaptor reuse. Good examples for such an API/SPI combinations are: JAXP, LDAP, DRMAA multiple implementations: ------------------------ the questions was raised whether it would be / should be possible to use multiple SAGA implementations in the same application. It was decided to not support this as no real need is seen. thread safety: ------------- The audience decided that simply requiring thread safety (and synchronization) of SAGA methods would simplify application development. An expected performance impact is considered of lesser importance, as the service times of remote services dominate invocation times anyway.