This is needed as explained by @krisis
Lets say we have following errors.
```
[]error{nil, errFileNotFound, errDiskAccessDenied, errDiskAccesDenied}
```
Since the last two errors are filtered, the maximum is nil,
depending on map order.
Let's say we get nil from reduceErr. Clearly at this point
we don't have quorum nodes agreeing about the data and since
GetObject only requires N/2 (Read quorum) and isDiskQuorum
would have returned true. This is problematic and can lead to
undersiable consequences.
Fixes#3298
Disks when are offline for a long period of time, we should
ignore the disk after trying Login upto 5 times.
This is to reduce the network chattiness, this also reduces
the overall time spent on `net.Dial`.
Fixes#3286
- Reads and writes of uploads.json in XL now uses quorum for
newMultipart, completeMultipart and abortMultipart operations.
- Each disk's `uploads.json` file is read and updated independently for
adding or removing an upload id from the file. Quorum is used to
decide if the high-level operation actually succeeded.
- Refactor FS code to simplify the flow, and fix a bug while reading
uploads.json.
The reason is any function relying on `getLoadBalancedQuorumDisks`
cannot possibly have an idempotent behavior.
The problem comes from given a set of N disks returning just a
shuffled N/2 disks. In case of a scenario where we have N/2
number of failed disks, the returned value of `getLoadBalancedQuorumDisks`
is not equal to the same failed disks so essentially calls using such
disks might succeed or fail randomly at different intervals in time.
This proposal change is we move to `getLoadBalancedDisks()`
and use the shuffled N disks as a whole. Since most of the time we might
hit a good disk since we are not reducing our solution space. This
also provides consistent behavior for all the functions which rely
on shuffled disks.
Fixes#2242
Each metadata ops have a list of errors which can be
ignored, this is essentially needed when
- disks are not found
- disks are found but cannot be accessed (permission denied)
- disks are there but fresh disks were added
This is needed since we don't have healing code in place where
it would have healed the fresh disks added.
Fixes#2072
Deletion of tmp files where xl metadata was saved before the commit
operation doesn't change the error returned to the caller. So, it is to
be ignored.
AppendFile ensures that it appends the entire buffer. Returns
an error otherwise, this patch removes the necessity for the
caller to look for 'n' return on short writes.
Ref #1893
* Remove parts that are missing in CompleteMultipartUpload
* Moved isUploadIDExists under proper namespace locks
* Moved code that deletes part files to a function
Bala FA