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https://issues.apache.org/jira/browse/HADOOP-19613?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18009544#comment-18009544
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ASF GitHub Bot commented on HADOOP-19613:
-----------------------------------------
anujmodi2021 commented on code in PR #7801:
URL: https://github.com/apache/hadoop/pull/7801#discussion_r2228246216
##########
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/ReadBufferManagerV1.java:
##########
@@ -39,28 +33,39 @@
* The Read Buffer Manager for Rest AbfsClient.
* V1 implementation of ReadBufferManager.
*/
-final class ReadBufferManagerV1 implements ReadBufferManager {
- private static final Logger LOGGER = LoggerFactory.getLogger(
- ReadBufferManagerV1.class);
- private static final int ONE_KB = 1024;
- private static final int ONE_MB = ONE_KB * ONE_KB;
+final class ReadBufferManagerV1 extends ReadBufferManager {
private static final int NUM_BUFFERS = 16;
private static final int NUM_THREADS = 8;
- private static final int DEFAULT_THRESHOLD_AGE_MILLISECONDS = 3000; // have
to see if 3 seconds is a good threshold
+ private static final int DEFAULT_THRESHOLD_AGE_MILLISECONDS = 3000;
- private static int blockSize = 4 * ONE_MB;
- private static int thresholdAgeMilliseconds =
DEFAULT_THRESHOLD_AGE_MILLISECONDS;
private Thread[] threads = new Thread[NUM_THREADS];
- private byte[][] buffers; // array of byte[] buffers, to hold the data
that is read
- private Stack<Integer> freeList = new Stack<>(); // indices in buffers[]
array that are available
+ private byte[][] buffers;
+ private static ReadBufferManagerV1 bufferManager;
Review Comment:
Not needed I think. Volatile is needed if someone is updating the value, but
here only once it is init and a static single copy of vairable is shared among
all streams.
Also, this was like this always
> ABFS: [ReadAheadV2] Refactor ReadBufferManager to isolate new code with the
> current working code
> ------------------------------------------------------------------------------------------------
>
> Key: HADOOP-19613
> URL: https://issues.apache.org/jira/browse/HADOOP-19613
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/azure
> Affects Versions: 3.5.0, 3.4.1
> Reporter: Anuj Modi
> Assignee: Anuj Modi
> Priority: Major
> Labels: pull-request-available
>
> Read Buffer Manager used today was introduced way back and has been stable
> for quite a while.
> Read Buffer Manager to be introduced as part of
> https://issues.apache.org/jira/browse/HADOOP-19596 will introduce many
> changes incrementally over time. While the development goes on and we are
> able to fully stabilise the optimized version we need the current flow to be
> functional and undisturbed.
> This work item is to isolate that from new code by refactoring
> ReadBufferManager class to have 2 different implementations with same public
> interfaces: ReadBufferManagerV1 and ReadBufferManagerV2.
> This will also introduce new configs that can be used to toggle between new
> and old code.
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