Package org.apache.hadoop.hdfs.util

Class CombinedHostsFileWriter

java.lang.Object

org.apache.hadoop.hdfs.util.CombinedHostsFileWriter

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

Writer 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"} ]

Method Summary

Modifier and Type	Method	Description
static void	writeFile(java.lang.String hostsFile, java.util.Set<DatanodeAdminProperties> allDNs)	Serialize a set of DatanodeAdminProperties to a json file.

Methods inherited from class java.lang.Object

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

Method Detail

writeFile

public static void writeFile(java.lang.String hostsFile,
                             java.util.Set<DatanodeAdminProperties> allDNs)
                      throws java.io.IOException

Serialize a set of DatanodeAdminProperties to a json file.

Parameters:

hostsFile - the json file name.

allDNs - the set of DatanodeAdminProperties

Throws:

java.io.IOException