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
Contributed by Steve Loughran and Gabor Bota.
This
* Asks S3Guard to determine the empty directory status.
* Has S3A's root directory rm("/") command to always return false (as abfs does)
* Documents that object stores MAY do this
* Overloads ContractTestUtils.assertDeleted to let assertions declare that the source directory does not need to exist. This stops inconsistencies in directory listings failing a root test.
It avoids a recent regression (HADOOP-16279) where if there was a tombstone above the first element found in a directory listing, the directory would be considered empty, when in fact there were child entries. That could downgrade an rm(path, recursive) to a no-op, while also confusing rename(src, dest), as dest could be mistaken for an empty directory and so permit the copy above it, rather than reject it "destination path exists and is not empty".
Change-Id: I136a3d1a5a48a67e6155d790a40ff558d0d2c108
Contributed by Steve Loughran
Contains
- HADOOP-16397. Hadoop S3Guard Prune command to support a -tombstone option.
- HADOOP-16406. ITestDynamoDBMetadataStore.testProvisionTable times out intermittently
This patch doesn't fix the underlying problem but it
* changes some tests to clean up better
* does a lot more in logging operations in against DDB, if enabled
* adds an entry point to dump the state of the metastore and s3 tables (precursor to fsck)
* adds a purge entry point to help clean up after a test run has got a store into a mess
* s3guard prune command adds -tombstone option to only clear tombstones
The outcome is that tests should pass consistently and if problems occur we have better diagnostics.
Change-Id: I3eca3f5529d7f6fec398c0ff0472919f08f054eb
Contributed by Steve Loughran.
This patch
* changes the default for the staging committer to append, as we get for the classic FileOutputFormat committer
* adds a check for the dest path being a file not a dir
* adds tests for this
* Changes AbstractCommitTerasortIT. to not use the simple parser, so fails if the file is present.
Change-Id: Id53742958ed1cf321ff96c9063505d64f3254f53