[HDFS-16817] Remove useless DataNode lock related configuration

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.4.0
• Fix Version/s: 3.4.0
• Component/s: datanode
• Labels: pull-request-available
• Target Version/s: 3.4.0
• Hadoop Flags: Reviewed
• Assignee: Haiyang Hu
• Reporter: Haiyang Hu
• Created: 25/Oct/22 00:31
• Updated: 28/Jan/24 07:57
• Resolved: 27/Oct/22 09:30

Description

When look at the code related to DataNode lock, it is found that the relevant configuration are invalid and maybe can be removed

public static final String DFS_DATANODE_LOCK_READ_WRITE_ENABLED_KEY =
"dfs.datanode.lock.read.write.enabled";
public static final Boolean DFS_DATANODE_LOCK_READ_WRITE_ENABLED_DEFAULT =
true;
public static final String  DFS_DATANODE_LOCK_REPORTING_THRESHOLD_MS_KEY =
"dfs.datanode.lock-reporting-threshold-ms";
public static final long
DFS_DATANODE_LOCK_REPORTING_THRESHOLD_MS_DEFAULT = 300L;

<property> 
<name> dfs.datanode.lock.read.write.enabled </name> 
<value> true </value> 
<description> If this is true, the FsDataset lock will be a read write lock. If
it is false, all locks will be a write lock.
Enabling this should give better datanode throughput, as many read only
functions can run concurrently under the read lock, when they would
previously have required the exclusive write lock. As the feature is
experimental, this switch can be used to disable the shared read lock, and
cause all lock acquisitions to use the exclusive write lock.
</description> 
</property> 

<property> 
<name> dfs.datanode.lock-reporting-threshold-ms </name> 
<value> 300 </value> 
<description> When thread waits to obtain a lock, or a thread holds a lock for
more than the threshold, a log message will be written. Note that
dfs.lock.suppress.warning.interval ensures a single log message is
emitted per interval for waiting threads and a single message for holding
threads to avoid excessive logging.
</description> 
</property> 

Issue Links

• links to: GitHub Pull Request #5072