S3AFileSystem.listStatus() is optimized for invocations
where the path supplied is a non-empty directory.
The number of S3 requests is significantly reduced, saving
time, money, and reducing the risk of S3 throttling.
Contributed by Mukund Thakur.
Contributed by Sneha Vijayarajan
DETAILS:
This change adds config key "fs.azure.enable.conditional.create.overwrite" with
a default of true. When enabled, if create(path, overwrite: true) is invoked
and the file exists, the ABFS driver will first obtain its etag and then attempt
to overwrite the file on the condition that the etag matches. The purpose of this
is to mitigate the non-idempotency of this method. Specifically, in the event of
a network error or similar, the client will retry and this can result in the file
being created more than once which may result in data loss. In essense this is
like a poor man's file handle, and will be addressed more thoroughly in the future
when support for lease is added to ABFS.
TEST RESULTS:
namespace.enabled=true
auth.type=SharedKey
-------------------
$mvn -T 1C -Dparallel-tests=abfs -Dscale -DtestsThreadCount=8 clean verify
Tests run: 87, Failures: 0, Errors: 0, Skipped: 0
Tests run: 457, Failures: 0, Errors: 0, Skipped: 42
Tests run: 207, Failures: 0, Errors: 0, Skipped: 24
namespace.enabled=true
auth.type=OAuth
-------------------
$mvn -T 1C -Dparallel-tests=abfs -Dscale -DtestsThreadCount=8 clean verify
Tests run: 87, Failures: 0, Errors: 0, Skipped: 0
Tests run: 457, Failures: 0, Errors: 0, Skipped: 74
Tests run: 207, Failures: 0, Errors: 0, Skipped: 140
This changes directory tree deletion so that only files are incrementally deleted
from S3Guard after the objects are deleted; the directories are left alone
until metadataStore.deleteSubtree(path) is invoke.
This avoids directory tombstones being added above files/child directories,
which stop the treewalk and delete phase from working.
Also:
* Callback to delete objects splits files and dirs so that
any problems deleting the dirs doesn't trigger s3guard updates
* New statistic to measure #of objects deleted, alongside request count.
* Callback listFilesAndEmptyDirectories renamed listFilesAndDirectoryMarkers
to clarify behavior.
* Test enhancements to replicate the failure and verify the fix
Contributed by Steve Loughran
Adds the options to control the size of the per-output-stream threadpool
when writing data through the abfs connector
* fs.azure.write.max.concurrent.requests
* fs.azure.write.max.requests.to.queue
Contributed by Bilahari T H
Contributed by Steve Loughran.
* Fixes AbstractContractSeekTest test to use readFully
* Doesn't do this to AbstractContractUnbufferTest test as it changes the test too much.
Instead just notes in the error that this may be transient
The issue is that read(buffer) doesn't guarantee that the buffer is filled, only that it will
read up to a point, and that may be just be the amount of data left in the TCP packet.
readFully corrects for this, but using it in the unbuffer test runs the risk that what
is tested for in terms of unbuffering doesn't actually get validated.
