Backport HADOOP-18546. ABFS:disable purging list of in progress reads in abfs stream closed #5176 #15
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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
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.
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Jun 27, 2023
create parent directory after deletion of given path is done
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JIRA: https://issues.apache.org/jira/browse/HADOOP-18546
Details:
AbfsInputStream.close() can trigger the return of buffers used for active prefetch GET requests into the ReadBufferManager free buffer pool.
A subsequent prefetch by a different stream in the same process may acquire this same buffer. This can lead to risk of corruption of its own prefetched data, data which may then be returned to that other thread.
Parent JIRA: https://issues.apache.org/jira/browse/HADOOP-18521
In this PR, we are disabling the purging of the inprogressList. The readBuffers in InProgressList will get to ReadBufferWorker and get processed and finally get into completedList. After a thresholdAgeMilliseconds, the readBuffer would be evicted (https://github.com/apache/hadoop/blob/trunk/hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/ReadBufferManager.java#L280-L285)
Commit apache@69e50c7 (HADOOP-18528. Disable abfs prefetching by default (apache#5134)) is reverted in the PR on commit: apache@02d39ca.
Config "fs.azure.enable.readahead" has value "true" in hadoop-common/src/main/resources/core-default.xml.