Contributed by Steve Loughran.
This complements the StreamCapabilities Interface by allowing applications to probe for a specific path on a specific instance of a FileSystem client
to offer a specific capability.
This is intended to allow applications to determine
* Whether a method is implemented before calling it and dealing with UnsupportedOperationException.
* Whether a specific feature is believed to be available in the remote store.
As well as a common set of capabilities defined in CommonPathCapabilities,
file systems are free to add their own capabilities, prefixed with
fs. + schema + .
The plan is to identify and document more capabilities -and for file systems which add new features, for a declaration of the availability of the feature to always be available.
Note
* The remote store is not expected to be checked for the feature;
It is more a check of client API and the client's configuration/knowledge
of the state of the remote system.
* Permissions are not checked.
Change-Id: I80bfebe94f4a8bdad8f3ac055495735b824968f5
In the existing implementation, the ValueQueue::getAtMost() method will only trigger a refill on a key queue if it has gone empty, instead of triggering a refill when it has gone below the watermark. Revise the test suite to correctly verify this behavior.
Contributed by Sahil Takiar.
This moves the SSLSocketFactoryEx class from hadoop-azure into hadoop-common
as the DelegatingSSLSocketFactory and binds the S3A connector to it so that
it can avoid using those HTTPS algorithms which are underperformant on Java 8.
Change-Id: Ie9e6ac24deac1aa05e136e08899620efa7d22abd
Contributed by Steve Loughran.
This patch avoids issuing any HEAD path request when creating a file with overwrite=true,
so 404s will not end up in the S3 load balancers unless someone calls getFileStatus/exists/isFile
in their own code.
The Hadoop FsShell CommandWithDestination class is modified to not register uncreated files
for deleteOnExit(), because that calls exists() and so can place the 404 in the cache, even
after S3A is patched to not do it itself.
Because S3Guard knows when a file should be present, it adds a special FileNotFound retry policy
independently configurable from other retry policies; it is also exponential, but with
different parameters. This is because every HEAD request will refresh any 404 cached in
the S3 Load Balancers. It's not enough to retry: we have to have a suitable gap between
attempts to (hopefully) ensure any cached entry wil be gone.
The options and values are:
fs.s3a.s3guard.consistency.retry.interval: 2s
fs.s3a.s3guard.consistency.retry.limit: 7
The S3A copy() method used during rename() raises a RemoteFileChangedException which is not caught
so not downgraded to false. Thus: when a rename is unrecoverable, this fact is propagated.
Copy operations without S3Guard lack the confidence that the file exists, so don't retry the same way:
it will fail fast with a different error message. However, because create(path, overwrite=false) no
longer does HEAD path, we can at least be confident that S3A itself is not creating those cached
404 markers.
Change-Id: Ia7807faad8b9a8546836cb19f816cccf17cca26d
Contributed by Steve Loughran.
This overlaps the scanning for directory entries with batched calls to S3 DELETE and updates of the S3Guard tables.
It also uses S3Guard to list the files to delete, so find newly created files even when S3 listings are not use consistent.
For path which the client considers S3Guard to be authoritative, we also do a recursive LIST of the store and delete files; this is to find unindexed files and do guarantee that the delete(path, true) call really does delete everything underneath.
Change-Id: Ice2f6e940c506e0b3a78fa534a99721b1698708e
