This PR implements an object layer which
combines input erasure sets of XL layers
into a unified namespace.
This object layer extends the existing
erasure coded implementation, it is assumed
in this design that providing > 16 disks is
a static configuration as well i.e if you started
the setup with 32 disks with 4 sets 8 disks per
pack then you would need to provide 4 sets always.
Some design details and restrictions:
- Objects are distributed using consistent ordering
to a unique erasure coded layer.
- Each pack has its own dsync so locks are synchronized
properly at pack (erasure layer).
- Each pack still has a maximum of 16 disks
requirement, you can start with multiple
such sets statically.
- Static sets set of disks and cannot be
changed, there is no elastic expansion allowed.
- Static sets set of disks and cannot be
changed, there is no elastic removal allowed.
- ListObjects() across sets can be noticeably
slower since List happens on all servers,
and is merged at this sets layer.
Fixes#5465Fixes#5464Fixes#5461Fixes#5460Fixes#5459Fixes#5458Fixes#5460Fixes#5488Fixes#5489Fixes#5497Fixes#5496
Currently minio master requires 4 servers, we
have decided to run on a minimum of 2 servers
instead - fixes a regression from previous
releases where 3 server setups were supported.
When running `make test` in docker, two test cases cause hanging.
This Patch fixes the problem by removing those test cases.
Thanks to @ws141 for identifying the problem.
It is possible at times due to a typo when distributed mode was intended
a user might end up starting standalone erasure mode causing confusion.
Add code to check this based on some standard heuristic guess work and
report an error to the user.
Fixes#4686
