Package org.apache.hadoop.hdfs.server.blockmanagement

Class SlowDiskTracker

java.lang.Object

org.apache.hadoop.hdfs.server.blockmanagement.SlowDiskTracker

@Private
@Unstable
public class SlowDiskTracker
extends java.lang.Object

This class aggregates information from SlowDiskReports received via heartbeats.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	SlowDiskTracker.DiskLatency	This structure is a thin wrapper over disk latencies.

Field Summary

Fields

Modifier and Type	Field	Description
static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor	Description
SlowDiskTracker(org.apache.hadoop.conf.Configuration conf, org.apache.hadoop.util.Timer timer)

Method Summary

Modifier and Type	Method	Description
void	addSlowDiskReport(java.lang.String dataNodeID, org.apache.hadoop.hdfs.server.protocol.SlowDiskReports dnSlowDiskReport)
void	checkAndUpdateReportIfNecessary()
static java.lang.String	getSlowDiskIDForReport(java.lang.String datanodeID, java.lang.String slowDisk)
java.lang.String	getSlowDiskReportAsJsonString()	Retrieve all valid reports as a JSON string.
void	updateSlowDiskReportAsync(long now)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

public static final org.slf4j.Logger LOG

Constructor Detail

SlowDiskTracker

public SlowDiskTracker(org.apache.hadoop.conf.Configuration conf,
                       org.apache.hadoop.util.Timer timer)

Method Detail

getSlowDiskIDForReport

@VisibleForTesting
public static java.lang.String getSlowDiskIDForReport(java.lang.String datanodeID,
                                                      java.lang.String slowDisk)

addSlowDiskReport

public void addSlowDiskReport(java.lang.String dataNodeID,
                              org.apache.hadoop.hdfs.server.protocol.SlowDiskReports dnSlowDiskReport)

checkAndUpdateReportIfNecessary

public void checkAndUpdateReportIfNecessary()

updateSlowDiskReportAsync

@VisibleForTesting
public void updateSlowDiskReportAsync(long now)

getSlowDiskReportAsJsonString

public java.lang.String getSlowDiskReportAsJsonString()

Retrieve all valid reports as a JSON string.

Returns:

serialized representation of valid reports. null if serialization failed.