ABFS has a client-side throttling mechanism which works on the metrics collected
from past requests
When requests are fail due to server-side throttling it updates its
metrics and recalculates any client side backoff.
The choice of which requests should be used to compute client side
backoff interval is based on the http status code:
- Status code in 2xx range: Successful Operations should contribute.
- Status code in 3xx range: Redirection Operations should not contribute.
- Status code in 4xx range: User Errors should not contribute.
- Status code is 503: Throttling Error should contribute only if they
are due to client limits breach as follows:
* 503, Ingress Over Account Limit: Should Contribute
* 503, Egress Over Account Limit: Should Contribute
* 503, TPS Over Account Limit: Should Contribute
* 503, Other Server Throttling: Should not Contribute.
- Status code in 5xx range other than 503: Should not Contribute.
- IOException and UnknownHostExceptions: Should not Contribute.
Contributed by Anuj Modi
Clarifies behaviour of VectorIO methods with contract tests as well as
specification.
* Add precondition range checks to all implementations
* Identify and fix bug where direct buffer reads was broken
(HADOOP-19101; this surfaced in ABFS contract tests)
* Logging in VectoredReadUtils.
* TestVectoredReadUtils verifies validation logic.
* FileRangeImpl toString() improvements
* CombinedFileRange tracks bytes in range which are wanted;
toString() output logs this.
HDFS
* Add test TestHDFSContractVectoredRead
ABFS
* Add test ITestAbfsFileSystemContractVectoredRead
S3A
* checks for vector IO being stopped in all iterative
vector operations, including draining
* maps read() returning -1 to failure
* passes in file length to validation
* Error reporting to only completeExceptionally() those ranges
which had not yet read data in.
* Improved logging.
readVectored()
* made synchronized. This is only for the invocation;
the actual async retrieves are unsynchronized.
* closes input stream on invocation
* switches to random IO, so avoids keeping any long-lived connection around.
+ AbstractSTestS3AHugeFiles enhancements.
+ ADDENDUM: test fix in ITestS3AContractVectoredRead
Contains: HADOOP-19101. Vectored Read into off-heap buffer broken in fallback
implementation
Contributed by Steve Loughran
Change-Id: Ia4ed71864c595f175c275aad83a2ff5741693432
Clarifies behaviour of VectorIO methods with contract tests as well as specification.
* Add precondition range checks to all implementations
* Identify and fix bug where direct buffer reads was broken
(HADOOP-19101; this surfaced in ABFS contract tests)
* Logging in VectoredReadUtils.
* TestVectoredReadUtils verifies validation logic.
* FileRangeImpl toString() improvements
* CombinedFileRange tracks bytes in range which are wanted;
toString() output logs this.
HDFS
* Add test TestHDFSContractVectoredRead
ABFS
* Add test ITestAbfsFileSystemContractVectoredRead
S3A
* checks for vector IO being stopped in all iterative
vector operations, including draining
* maps read() returning -1 to failure
* passes in file length to validation
* Error reporting to only completeExceptionally() those ranges
which had not yet read data in.
* Improved logging.
readVectored()
* made synchronized. This is only for the invocation;
the actual async retrieves are unsynchronized.
* closes input stream on invocation
* switches to random IO, so avoids keeping any long-lived connection around.
+ AbstractSTestS3AHugeFiles enhancements.
Contains: HADOOP-19101. Vectored Read into off-heap buffer broken in fallback implementation
Contributed by Steve Loughran
This reverts most of
HADOOP-18869: [ABFS] Fix behavior of a File System APIs on root path (#6003).
Calling getXAttr("/") or setXAttr("/") on an abfs container will fail with
`Operation failed: "The request URI is invalid.", HTTP 400 Bad Request`
This change is to ensure:
* Consistency across ADLS clients
* Consistency across authentication mechanisms.
Contributed by Anuj Modi
Address JDK bug JDK-8314978 related to handling of HTTP 100
responses.
https://bugs.openjdk.org/browse/JDK-8314978
In the AbfsHttpOperation, after sendRequest() we call processResponse()
method from AbfsRestOperation.
Even if the conn.getOutputStream() fails due to expect-100 error,
we consume the exception and let the code go ahead.
This may call getHeaderField() / getHeaderFields() / getHeaderFieldLong() after
getOutputStream() has failed. These invocation all lead to server calls.
This commit aims to prevent this.
If connection.getOutputStream() fails due to an Expect-100 error,
the ABFS client does not invoke getHeaderField(), getHeaderFields(),
getHeaderFieldLong() or getInputStream().
getResponseCode() is safe as on the failure it sets the
responseCode variable in HttpUrlConnection object.
Contributed by Pranav Saxena
The option fs.azure.footer.read.request.size sets the size of the footer to
read and cache; the default value of 524288 has been measured to
be good for most workloads running on parquet, ORC and similar file formats.
Contributed by Anuj Modi
The default value for fs.azure.data.blocks.buffer is changed from "disk" to "bytebuffer"
This will speed up writing to azure storage, at the risk of running out of memory
-especially if there are many threads writing to abfs at the same time and the
upload bandwidth is limited.
If jobs do run out of memory writing to abfs, change the option back to "disk"
Contributed by Anmol Asrani
To avoid the ABFS instance getting closed due to GC while the streams are working, attach the ABFS instance to a backReference opaque object and passing down to the streams so that we have a hard reference while the streams are working.
Contributed by: Mehakmeet Singh
This modifies the manifest committer so that the list of files
to rename is passed between stages as a file of
writeable entries on the local filesystem.
The map of directories to create is still passed in memory;
this map is built across all tasks, so even if many tasks
created files, if they all write into the same set of directories
the memory needed is O(directories) with the
task count not a factor.
The _SUCCESS file reports on heap size through gauges.
This should give a warning if there are problems.
Contributed by Steve Loughran
This:
1. Adds optLong, optDouble, mustLong and mustDouble
methods to the FSBuilder interface to let callers explicitly
passin long and double arguments.
2. The opt() and must() builder calls which take float/double values
now only set long values instead, so as to avoid problems
related to overloaded methods resulting in a ".0" being appended
to a long value.
3. All of the relevant opt/must calls in the hadoop codebase move to
the new methods
4. And the s3a code is resilient to parse errors in is numeric options
-it will downgrade to the default.
This is nominally incompatible, but the floating-point builder methods
were never used: nothing currently expects floating point numbers.
For anyone who wants to safely set numeric builder options across all compatible
releases, convert the number to a string and then use the opt(String, String)
and must(String, String) methods.
Contributed by Steve Loughran
To support recovery of network failures during rename, the abfs client
fetches the etag of the source file, and when recovering from a
failure, uses this tag to determine whether the rename succeeded
before the failure happened.
* This works for files, but not directories
* It adds the overhead of a HEAD request before each rename.
* The option can be disabled by setting "fs.azure.enable.rename.resilience"
to false
Contributed by Sree Bhattacharyya
This change lets the client react pre-emptively to server load without getting to 503 and the exponential backoff
which follows. This stops performance suffering so much as capacity limits are approached for an account.
Contributed by Anmol Asranii
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 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
