[
https://issues.apache.org/jira/browse/HDFS-16520?focusedWorklogId=761571&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-761571
]
ASF GitHub Bot logged work on HDFS-16520:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 25/Apr/22 03:26
Start Date: 25/Apr/22 03:26
Worklog Time Spent: 10m
Work Description: cndaimin commented on code in PR #4104:
URL: https://github.com/apache/hadoop/pull/4104#discussion_r857234796
##########
hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSStripedInputStream.java:
##########
@@ -250,9 +255,16 @@ boolean createBlockReader(LocatedBlock block, long
offsetInBlock,
if (dnInfo == null) {
break;
}
+ if (readTo < 0 || readTo > block.getBlockSize()) {
+ readTo = block.getBlockSize();
+ }
reader = getBlockReader(block, offsetInBlock,
- block.getBlockSize() - offsetInBlock,
+ readTo - offsetInBlock,
dnInfo.addr, dnInfo.storageType, dnInfo.info);
+ if (blockReaderListener != null) {
Review Comment:
> It is for test here, right? Can we use fault injector here? Refer to
DFSClientFaultInjector
Yes, `DFSClientFaultInjector` is better here. Thanks, updated.
Issue Time Tracking
-------------------
Worklog Id: (was: 761571)
Time Spent: 2.5h (was: 2h 20m)
> Improve EC pread: avoid potential reading whole block
> -----------------------------------------------------
>
> Key: HDFS-16520
> URL: https://issues.apache.org/jira/browse/HDFS-16520
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: dfsclient, ec
> Affects Versions: 3.3.1, 3.3.2
> Reporter: daimin
> Assignee: daimin
> Priority: Major
> Labels: pull-request-available
> Time Spent: 2.5h
> Remaining Estimate: 0h
>
> HDFS client 'pread' represents 'position read', this kind of read just need a
> range of data instead of reading the whole file/block. By using
> BlockReaderFactory#setLength, client tells datanode the block length to be
> read from disk and sent to client.
> To EC file, the block length to read is not well set, by default using
> 'block.getBlockSize() - offsetInBlock' to both pread and sread. Thus datanode
> read much more data and send to client, and abort when client closes
> connection. There is a lot waste of resource to this situation.
--
This message was sent by Atlassian Jira
(v8.20.7#820007)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
