Fixes a javadoc error which came with
HADOOP-18577. ABFS: Add probes of readahead fix (#5205)
Part of the HADOOP-18521 ABFS readahead fix; MUST be included.
Contributed by Steve Loughran
Followup patch to HADOOP-18456 as part of HADOOP-18521,
ABFS ReadBufferManager buffer sharing across concurrent HTTP requests
Add probes of readahead fix aid in checking safety of
hadoop ABFS client across different releases.
* ReadBufferManager constructor logs the fact it is safe at TRACE
* AbfsInputStream declares it is fixed in toString()
by including fs.azure.capability.readahead.safe" in the
result.
The ABFS FileSystem hasPathCapability("fs.azure.capability.readahead.safe")
probe returns true to indicate the client's readahead manager has been fixed
to be safe when prefetching.
All Hadoop releases for which probe this returns false
and for which the probe "fs.capability.etags.available"
returns true at risk of returning invalid data when reading
ADLS Gen2/Azure storage data.
Contributed by Steve Loughran.
This has triggered an OOM in a process which was churning through s3a fs
instances; the increased memory footprint of IOStatistics amplified what
must have been a long-standing issue with FS instances being created
and not closed()
* Makes sure instrumentation is closed when the FS is closed.
* Uses a weak reference from metrics to instrumentation, so even
if the FS wasn't closed (see HADOOP-18478), this back reference
would not cause the S3AInstrumentation reference to be retained.
* If S3AFileSystem is configured to log at TRACE it will log the
calling stack of initialize(), so help identify where the
instance is being created. This should help track down
the cause of instance leakage.
Contributed by Steve Loughran.
This is a followup to the original HADOOP-18546
patch; cherry-picks of that should include this
or follow up with it.
Removes risk of race conditions in assertions
of ITestReadBufferManager on the state of the in-progress
and completed queues by removing assertions brittle
to race conditions in scheduling/network IO
* Waits for all the executor pool shutdown to complete before
making any assertions
* Assertions that there are no in progress reads MUST be
cut as there may be some and they won't be cancelled.
* Assertions that the completed list is without buffers
of a closed stream are brittle because if there was
an in progress stream which completed after stream.close()
then it will end up in the list.
Contributed by Steve Loughran
This addresses HADOOP-18521, "ABFS ReadBufferManager buffer sharing
across concurrent HTTP requests" by not trying to cancel
in progress reads.
It supercedes HADOOP-18528, which disables the prefetching.
If that patch is applied *after* this one, prefetching
will be disabled.
As well as changing the default value in the code,
core-default.xml is updated to set
fs.azure.enable.readahead = true
As a result, if Configuration.get("fs.azure.enable.readahead")
returns a non-null value, then it can be inferred that
it was set in or core-default.xml (the fix is present)
or in core-site.xml (someone asked for it).
Contributed by Pranav Saxena.
This allows abfs request throttling to be shared across all
abfs connections talking to containers belonging to the same abfs storage
account -as that is the level at which IO throttling is applied.
The option is enabled/disabled in the configuration option
"fs.azure.account.throttling.enabled";
The default is "true"
Contributed by Anmol Asrani
This commit parses SAS Tokens and removes the unwanted prefix of '?' from them, if present.
At present, SAS Tokens are provided to the driver through customer implementations of the SASTokenProvider interface. The SAS token providers should not assume that the token will be the first query parameter in the URIs that communicate with the backend. However, it was observed that certain public interfaces provided by Storage to generate SAS can include the '?' as the first character of the SAS Token, which would ideally be the case when it is the first query parameter. Thus, tokens that contain this prefix will lead to an error in the driver due to a clash of query parameters.
To avoid failures for use of such SAS tokens, after receiving the SAS Token from the provider, the code checks for whether any ? prefix is present or not. If yes, it is removed before further usage of the token. This way, users would not have to manually remove the prefix before passing it on as a configuration.
Contributed by Sree Bhattacharya
Disables block prefetching on ABFS InputStreams, by setting
fs.azure.enable.readahead to false in core-default.xml and
the matching java constant.
This prevents
HADOOP-18521. ABFS ReadBufferManager buffer sharing across concurrent HTTP requests.
Once a fix for that is committed, this change can be reverted.
Contributed by Mehakmeet Singh.
* HADOOP-18517. ABFS: Add fs.azure.enable.readahead option to disable readahead
Adds new config option to turn off readahead
* also allows it to be passed in through openFile(),
* extends ITestAbfsReadWriteAndSeek to use the option, including one
replicated test...that shows that turning it off is slower.
Important: this does not address the critical data corruption issue
HADOOP-18521. ABFS ReadBufferManager buffer sharing across concurrent HTTP requests
What is does do is provide a way to completely bypass the ReadBufferManager.
To mitigate the problem, either fs.azure.enable.readahead needs to be set to false,
or set "fs.azure.readaheadqueue.depth" to 0 -this still goes near the (broken)
ReadBufferManager code, but does't trigger the bug.
For safe reading of files through the ABFS connector, readahead MUST be disabled
or the followup fix to HADOOP-18521 applied
Contributed by Steve Loughran
This fixes a race condition with the TemporaryAWSCredentialProvider
one which has existed for a long time but which only surfaced
(usually in Spark) when the bucket existence probe was disabled
by setting fs.s3a.bucket.probe to 0 -a performance speedup
which was made the default in HADOOP-17454.
Contributed by Jimmy Wong.
The option "fs.s3a.proxy.ssl.enabled" controls
whether the s3a connects to a proxy over HTTP (default) or HTTPS.
Set to "true" to use HTTPS.
Contributed by Mehakmeet Singh
The AWS SDKV2 upgrade log no longer warns about instantiation
of the v1 SDK credential providers which are commonly used in
s3a configurations:
* com.amazonaws.auth.EnvironmentVariableCredentialsProvider
* com.amazonaws.auth.EC2ContainerCredentialsProviderWrapper
* com.amazonaws.auth.InstanceProfileCredentialsProvider
When the hadoop-aws module moves to the v2 SDK, references to these
credential providers will be rewritten to their v2 equivalents.
Follow-on to HADOOP-18382. "Upgrade AWS SDK to V2 - Prerequisites"
Contributed by Ahmar Suhail
Add to XMLUtils a set of methods to create secure XML Parsers/transformers, locking down DTD, schema, XXE exposure.
Use these wherever XML parsers are created.
Contributed by PJ Fanning
Make S3APrefetchingInputStream.seek() completely lazy. Calls to seek() will not affect the current buffer nor interfere with prefetching, until read() is called.
This change allows various usage patterns to benefit from prefetching, e.g. when calling readFully(position, buffer) in a loop for contiguous positions the intermediate internal calls to seek() will be noops and prefetching will have the same performance as in a sequential read.
Contributed by Alessandro Passaro.
part of HADOOP-18103.
Also introducing a config fs.s3a.vectored.active.ranged.reads
to configure the maximum number of number of range reads a
single input stream can have active (downloading, or queued)
to the central FileSystem instance's pool of queued operations.
This stops a single stream overloading the shared thread pool.
Contributed by: Mukund Thakur
part of HADOOP-18103.
While merging the ranges in CheckSumFs, they are rounded up based on the
value of checksum bytes size which leads to some ranges crossing the EOF
thus they need to be fixed else it will cause EOFException during actual reads.
Contributed By: Mukund Thakur
Follow-up to HADOOP-12020 Support configuration of different S3 storage classes;
S3 storage class is now set when buffering to heap/bytebuffers, and when
creating directory markers
Contributed by Monthon Klongklaew
HADOOP-16202 "Enhance openFile()" added asynchronous draining of the
remaining bytes of an S3 HTTP input stream for those operations
(unbuffer, seek) where it could avoid blocking the active
thread.
This patch fixes the asynchronous stream draining to work and so
return the stream back to the http pool. Without this, whenever
unbuffer() or seek() was called on a stream and an asynchronous
drain triggered, the connection was not returned; eventually
the pool would be empty and subsequent S3 requests would
fail with the message "Timeout waiting for connection from pool"
The root cause was that even though the fields passed in to drain() were
converted to references through the methods, in the lambda expression
passed in to submit, they were direct references
operation = client.submit(
() -> drain(uri, streamStatistics,
false, reason, remaining,
object, wrappedStream)); /* here */
Those fields were only read during the async execution, at which
point they would have been set to null (or even a subsequent read).
A new SDKStreamDrainer class peforms the draining; this is a Callable
and can be submitted directly to the executor pool.
The class is used in both the classic and prefetching s3a input streams.
Also, calling unbuffer() switches the S3AInputStream from adaptive
to random IO mode; that is, it is considered a cue that future
IO will not be sequential, whole-file reads.
Contributed by Steve Loughran.
This patch prepares the hadoop-aws module for a future
migration to using the v2 AWS SDK (HADOOP-18073)
That upgrade will be incompatible; this patch prepares
for it:
-marks some credential providers and other
classes and methods as @deprecated.
-updates site documentation
-reduces the visibility of the s3 client;
other than for testing, it is kept private to
the S3AFileSystem class.
-logs some warnings when deprecated APIs are used.
The warning messages are printed only once
per JVM's life. To disable them, set the
log level of org.apache.hadoop.fs.s3a.SDKV2Upgrade
to ERROR
Contributed by Ahmar Suhail
