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https://issues.apache.org/jira/browse/HADOOP-19354?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17926415#comment-17926415
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ASF GitHub Bot commented on HADOOP-19354:
-----------------------------------------
steveloughran commented on code in PR #7214:
URL: https://github.com/apache/hadoop/pull/7214#discussion_r1952836839
##########
hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java:
##########
@@ -1877,100 +1868,41 @@ private FSDataInputStream executeOpen(
fileInformation.applyOptions(readContext);
LOG.debug("Opening '{}'", readContext);
- if (this.prefetchEnabled) {
- Configuration configuration = getConf();
- initLocalDirAllocatorIfNotInitialized(configuration);
- return new FSDataInputStream(
- new S3APrefetchingInputStream(
- readContext.build(),
- createObjectAttributes(path, fileStatus),
- createInputStreamCallbacks(auditSpan),
- inputStreamStats,
- configuration,
- directoryAllocator));
- } else {
- return new FSDataInputStream(
- new S3AInputStream(
- readContext.build(),
- createObjectAttributes(path, fileStatus),
- createInputStreamCallbacks(auditSpan),
- inputStreamStats,
- new SemaphoredDelegatingExecutor(
- boundedThreadPool,
- vectoredActiveRangeReads,
- true,
- inputStreamStats)));
- }
- }
-
- /**
- * Override point: create the callbacks for S3AInputStream.
- * @return an implementation of the InputStreamCallbacks,
- */
- private S3AInputStream.InputStreamCallbacks createInputStreamCallbacks(
+ // what does the stream need
+ final StreamFactoryRequirements requirements =
+ getStore().factoryRequirements();
+
+ // calculate the permit count.
+ final int permitCount = requirements.streamThreads()
+ + requirements.vectoredIOContext().getVectoredActiveRangeReads();
+ // create an executor which is a subset of the
+ // bounded thread pool.
+ final SemaphoredDelegatingExecutor pool = new SemaphoredDelegatingExecutor(
+ boundedThreadPool,
+ permitCount,
+ true,
+ inputStreamStats);
+
+ // do not validate() the parameters as the store
+ // completes this.
+ ObjectReadParameters parameters = new ObjectReadParameters()
Review Comment:
ooh, wire up to history is good. But does it have an expiry? can we turn it
off? I ask as caches can be their own source of pain, and for other use cases
they do cause problems.
If you look at how parquet and iceberg open files, they do have the file
status first, so we just need to wire up passing down that FileStatus, along
with file type, and if known: footer location.
parquet does now pass down its status, so the HEAD is skipped.
> S3A: InputStreams to be created by factory under S3AStore
> ---------------------------------------------------------
>
> Key: HADOOP-19354
> URL: https://issues.apache.org/jira/browse/HADOOP-19354
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3
> Affects Versions: 3.4.2
> Reporter: Steve Loughran
> Assignee: Steve Loughran
> Priority: Major
> Labels: pull-request-available
>
> Migrate S3AInputStream creation into a factory pattern, push down into
> S3AStore.
> Proposed factories
> * default: whatever this release has as default
> * classic: current S3AInputStream
> * prefetch: prefetching
> * analytics: new analytics stream
> * other: reads a classname from another prop, instantiates.
> Also proposed
> * stream to implement some stream capability to declare what they are
> (classic, prefetch, analytics, other).
> h2. Implementation
> All callbacks used by the stream also to call directly onto S3AStore.
> S3AFileSystem must not be invoked at all (if it is needed: PR is still not
> ready).
> Some interface from Instrumentation will be passed to factory; this shall
> include a way to create new per-stream
> The factory shall implement org.apache.hadoop.service.Service; S3AStore shall
> do same and become a subclass of CompositeService. It shall attach the
> factory as a child, so they can follow the same lifecycle. We shall do the
> same for anything else that gets pushed down.
> Everything related to stream creation must go from s3afs; and creation of the
> factory itself. This must be done in S3AStore.initialize().
> As usual, this will complicate mocking. But the streams themselves should not
> require changes, at least significant ones.
> Testing.
> * The huge file tests should be tuned so each of the different ones uses a
> different stream, always.
> * use a -Dstream="factory name" to choose factory, rather than the -Dprefetch
> * if not set, whatever is in auth-keys gets picked up.
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