- Fedora 6 open questions and design issues
- OCFL only. Should Fedora 6 support multiple storage layer technologies, or just the OCFL specification? Some feel that Fedora 6 should not be strictly tied to only OCFL. Also being able to work with cloud storage is a major concern (see below, "Cloud").
- Implicit OCFL. Many people see value in a filesystem storage layer, such as specified in OCFL, for Fedora; however, do not want to tie Fedora 6 strictly to OCFL. Is there value in indicating that the Fedora 6 design will provide filesystem-based storage without explicitly stating that the storage spec is OCFL, and just use OCFL under the hood?
- Other filesystem approaches. A filesystem-based storage approach seems like a useful option for Fedora 6 in any case. If Fedora 6 were to use a filesystem-based storage approach that was not OCFL, what would it use? What would be the value proposition of that storage approach over OCFL?
- Pluggable storage. There seems to be a desire for a diversity of storage options. If Fedora 6 were to support multiple storage layer technologies (e.g., OCFL, PostgreSQL), would these storage options need to be available via a single Fedora distribution (internal pluggable components), possibly the default community implementation? Or should these be wholly separate Fedora implementations of the Fedora spec?
- Transparency. The group feels that regardless of the storage technology used, the technology should offer file transparency. It should be obvious to humans how to access, navigate and interpret the files stored by Fedora. It may be useful for Fedora to cache items in a non-transparent manner for performance, but by default Fedora should offer file transparency.
- An interesting thought exercise is to imagine a version of Fedora (4, 5) that uses Modeshape but did not suffer from the "many members" (or other?) performance limitations. In Modeshape files are not transparent and not easily human-understandable. Would such a performant Fedora-Modeshape have broad community appeal, even if it lacks file transparency?
- Some participants felt that a Fedora implementation that resolved the performance issues inherent in the current implementation (specifically "many members"), and that could both read from and write to OCFL (via import/export tooling), but which did not use OCFL as its native storage layer, could be a sufficient solution.
- It could be useful to explore using the current export tool to persist resources to disk and then use the prototype OCFL clients to create OCFL objects from these exported resources. Modifying the existing import tool to be able to re-ingest an OCFL-ized export seems like low-hanging fruit.
- Data preparation. OCFL seems to make great sense for the use case of organizing files in advance, and then presenting Fedora with this organization. What about the use case when Fedora is presented with the files via the API, and must store the files? Should the files be stored within an OCFL structure as well, or something else?
- Maturity. OCFL is still an untested pre-beta specification. Is it mature enough to use as the only storage technology for Fedora 6? It seems similar to the level of maturity of WebAC when Fedora started with it.
- Performance. File transparency likely comes at a cost in performance. Internal caches may improve performance but could introduce problems if there is delay in synchronising the authoritative store with the cache. Apparently in the past, some organizations have indicated that a one second delay in such synchronisation was unacceptable. How big of a concern is performance in this respect? The group generally feels that the majority of Fedora use cases do not have such stringent performance requirements, and would greatly benefit from file transparency. Fedora users are generally not concerned with high performance computing, and this use case is perhaps better met by a specialised Fedora implementation or another application.
- Cloud. Many organisations are moving to the cloud and it seems reasonable to expect to be able to run Fedora 6 in the cloud, and in particular, on AWS S3. Recent OCFL community calls have implied that OCFL is geared towards POSIX filesystems. Will use of OCFL introduce limitations to Fedora in a cloud environment? Will EBS be required to run Fedora 6 within AWS?
- Fedora 6 development
- In order to obtain institutional commitments to use Fedora 6, it would be helpful to have a basic design in place that answers many of the above questions. This would allow institutions to determine the feasibility of using the product.
- A working prototype may also enable institutions to better evaluate their potential use of Fedora 6. However, prototype development in advance of detailed design (above) may not be a good use of resources.
- To drive adoption, Fedora 6 should be reasonably simple to use, offer file transparency, and offer a migration path for the existing broad Fedora 3 user base.
- The group notes that additional support is needed to develop Fedora 6, in addition to the current technical team.