Package org.apache.hadoop.hdfs.util

Class CombinedHostsFileReader

java.lang.Object

org.apache.hadoop.hdfs.util.CombinedHostsFileReader

@LimitedPrivate("HDFS")
@Unstable
public final class CombinedHostsFileReader
extends java.lang.Object

Reader support for JSON-based datanode configuration, an alternative format to the exclude/include files configuration. The JSON file format defines the array of elements where each element in the array describes the properties of a datanode. The properties of a datanode is defined by DatanodeAdminProperties. For example, [ {"hostName": "host1"}, {"hostName": "host2", "port": 50, "upgradeDomain": "ud0"}, {"hostName": "host3", "port": 0, "adminState": "DECOMMISSIONED"} ]

Field Summary

Fields

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

Method Summary

Modifier and Type	Method	Description
static DatanodeAdminProperties[]	readFile(java.lang.String hostsFilePath)	Deserialize a set of DatanodeAdminProperties from a json file.

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

Method Detail

readFile

public static DatanodeAdminProperties[] readFile(java.lang.String hostsFilePath)
                                          throws java.io.IOException

Deserialize a set of DatanodeAdminProperties from a json file.

Parameters:

hostsFilePath - the input json file to read from

Returns:

the set of DatanodeAdminProperties

Throws:

java.io.IOException