download as a pdf - Southern California Coastal Ocean Observing ...

Part III. Appendix 2: Data TransportMediated facilities: a form of distributed computingData aggregation: The “Aggregation Server”Recall that requests from a client to a server are by qualified URL and that in its usual form, a URLrefers to a single file. When the data that a client wants reside in more than one file, we use “dataaggregation,” which is any process whereby a data set is generated by joining in some manner dataheld in more than one data set, probably in more than one file and possibly at more than one site.Aggregation is presently supported by the OPeNDAP/THREDDS Aggregation server. Thismakes it possible to combine multi-file grids and arrays into single file data sets. For more detailson the types of aggregations supported by the existing Aggregation Server see: http://www.unidata.ucar.edu/projects/THREDDS/tech/AggServerConfig.html#aggTypesThe existing Aggregation Server does not support the reordering of axes, e.g., x(i,j,k) ==> x(j,i,k),and by the reasoning laid out in this Plan, it should not. Such a mapping would be the province ofa Restructuring Server.Platforms/operating systems currently supported byOPeNDAP/NVODSThe following are already supported:• Intel x86: Linux 2.2 and 2.4 (Red Hat 6.2, 7.1, 7.2, 7.3, plus other Linux distributions that use the2.2 or 2.4 kernels; i.e., virtually all of them).• SGI/IRIX 6.5• Sun/Solaris 2.6 (but that runs on 2.7 also)• Dec Alpha: OSF 4.0f• Intel x86: Windows2000, NT, XPServer-side data storage formats currently supportedby OPeNDAP/NVODSGiven that the IOOS data access protocol will be based on open source software, nothing restrictsdevelopment in supporting data storage formats. Nevertheless, certain data storage formats arewidely enough used in oceanography that they warrant explicit support in the IOOS effort. Thefirst items in the list are currently supported by NVODS (or by NVODS affiliates); following theseare items which IOOS should probably support.190