[
https://issues.apache.org/jira/browse/HDFS-16939?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17696146#comment-17696146
]
ASF GitHub Bot commented on HDFS-16939:
---------------------------------------
zhangshuyan0 commented on code in PR #5450:
URL: https://github.com/apache/hadoop/pull/5450#discussion_r1124398378
##########
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/LowRedundancyBlocks.java:
##########
@@ -369,7 +369,7 @@ synchronized boolean remove(BlockInfo block,
* @return true if the block was found and removed from one of the priority
* queues
*/
- boolean remove(BlockInfo block, int priLevel) {
+ synchronized boolean remove(BlockInfo block, int priLevel) {
Review Comment:
> This will just ensure only one thread getting into the remove method. But
what if there is one thread trying to remove, other trying to add or size().
add() and size() are already synchronized in the current code.
1.
https://github.com/apache/hadoop/blob/01027e52a9789eb5b386729f52b7bb9e52fa5352/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/LowRedundancyBlocks.java#L290
2.
https://github.com/apache/hadoop/blob/01027e52a9789eb5b386729f52b7bb9e52fa5352/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/LowRedundancyBlocks.java#L125
> Fix the thread safety bug in LowRedundancyBlocks
> ------------------------------------------------
>
> Key: HDFS-16939
> URL: https://issues.apache.org/jira/browse/HDFS-16939
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namanode
> Reporter: Shuyan Zhang
> Assignee: Shuyan Zhang
> Priority: Major
> Labels: pull-request-available
>
> The remove method in LowRedundancyBlocks is not protected by synchronized.
> This method is private and is called by BlockManager. As a result,
> priorityQueues has the risk of being accessed concurrently by multiple
> threads.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
