Package org.apache.hadoop.hdfs.server.datanode.checker

Class StorageLocationChecker

java.lang.Object

org.apache.hadoop.hdfs.server.datanode.checker.StorageLocationChecker

@Private
@Unstable
public class StorageLocationChecker
extends Object

A utility class that encapsulates checking storage locations during DataNode startup. Some of this code was extracted from the DataNode class.

Field Summary

Fields

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

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
List<StorageLocation>	check(org.apache.hadoop.conf.Configuration conf, Collection<StorageLocation> dataDirs)	Initiate a check on the supplied storage volumes and return a list of healthy volumes.
void	shutdownAndWait(int gracePeriod, TimeUnit timeUnit)

Methods inherited from class java.lang.Object

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

Field Details

LOG

public static final org.slf4j.Logger LOG

Constructor Details

StorageLocationChecker

public StorageLocationChecker(org.apache.hadoop.conf.Configuration conf,
 org.apache.hadoop.util.Timer timer)
                       throws org.apache.hadoop.util.DiskChecker.DiskErrorException

Throws:

org.apache.hadoop.util.DiskChecker.DiskErrorException

Method Details

check

public List<StorageLocation> check(org.apache.hadoop.conf.Configuration conf,
 Collection<StorageLocation> dataDirs)
                            throws InterruptedException,
IOException

Initiate a check on the supplied storage volumes and return a list of healthy volumes. StorageLocations are returned in the same order as the input for compatibility with existing unit tests.

Parameters:

conf - HDFS configuration.

dataDirs - list of volumes to check.

Returns:

returns a list of healthy volumes. Returns an empty list if there are no healthy volumes.

Throws:

InterruptedException - if the check was interrupted.

IOException - if the number of failed volumes exceeds the maximum allowed or if there are no good volumes.

shutdownAndWait

public void shutdownAndWait(int gracePeriod,
 TimeUnit timeUnit)