Hi Mahesh,
When starting the NN, it will throw exception with your provided configuration.
please check the code snippet below where exactly validation will happen.
in NameNode:
public static InetSocketAddress getAddress(URI filesystemURI) {
String authority = filesystemURI.getAuthority();
if (authority == null) {
throw new IllegalArgumentException(String.format(
"Invalid URI for NameNode address (check %s): %s has no authority.",
FileSystem.FS_DEFAULT_NAME_KEY, filesystemURI.toString()));
}
if (!FSConstants.HDFS_URI_SCHEME.equalsIgnoreCase(
filesystemURI.getScheme())) {
throw new IllegalArgumentException(String.format(
"Invalid URI for NameNode address (check %s): %s is not of scheme
'%s'.",
FileSystem.FS_DEFAULT_NAME_KEY, filesystemURI.toString(),
FSConstants.HDFS_URI_SCHEME));
}
Since NN is specific to HDFS, it will expect scheme as hdfs. Otherwise it will
throw the exception.
If you develop your own file system, then clients will have intelligence to
connect to that file system, based on your provided configuration for
fs.default.name.
Coming to clients side, if you pass file:/// as fs uri, it will not try to
connect to DFS because your passed fs is related to local. So, it will create
LocalFileSystem instead of DistributedFilesystem.
Regards,
Uma
Regards,
Uma
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----- Original Message -----
From: Mahesh Shinde <[email protected]>
Date: Saturday, July 23, 2011 4:17 pm
Subject: FW: Question about property "fs.default.name"
To: "[email protected]" <[email protected]>
>
>
> Hi,
>
> I have basic question on property "fs.default.name" is that I am
> not able to open NameNode URL when I set fs.default.name=file:/// .
> If we define not use HDFS as our file system then how hadoop deals
> with File system of local?..
> Please reply.
>
> Mahesh Shinde | Systems Engineer
> [email protected]<mailto:[email protected]>| Cell:
> +918308321501 | Tel: +91-20-30235194
> Persistent Systems Ltd. | 20 Glorious Years |
> www.persistentsys.com<http://www.persistentsys.com/>
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