BlockLocation---datanodeInfo

BlockLocation代码跟踪
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1.client-->[DistributedFileSystem.class]fs.getFileBlockLocations
-->[DistributedFileSystem.class]fs.getFileBlockLocations(重载)
-->[DFSClient.class]dfs.getBlockLocations
-->[DFSClient.class]getLocatedBlocks
-->[DFSClient.class]callGetBlockLocations
-->[Clientprotocol.class]getBlockLocations
-->[NameNodeRpcServer.class]getBlockLocations
-->[FSNamesystem.class]namesystem.getBlockLocations //FSNamesystem剑指namenode

通过FileSystem API访问BlockLocations块位置信息
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/**
* 通过FileSystem API访问BlockLocations块位置信息
* @throws IOException
*/
@Test
public void BlockLByFS() throws IOException{
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
Path file = new Path("/spaceQuota/hello.txt");
FileStatus fst = fs.getFileStatus(file);
BlockLocation[] blocklocations = fs.getFileBlockLocations(fst, 8, 30);
// BlockLocation[] blocklocations = fs.getFileBlockLocations(fst, 0, 30);
for (BlockLocation blockLocation : blocklocations) {
String[] hosts = blockLocation.getHosts();
for (String host : hosts) {
System.out.println(host);
}
String[] names = blockLocation.getNames();
for (String name : names) {
System.out.println(name);
}
String[] topologs = blockLocation.getTopologyPaths();
for (String topolog : topologs) {
System.out.println(topolog);
}
}
}

通过FileSystem API访问Datanode信息
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/**
* 通过FileSystem API访问Datanode信息
* @throws IOException
*/
@Test
public void datanodeLByFS() throws IOException{
Configuration conf = new Configuration();
System.setProperty("HADOOP_USER_NAME", "hyxy");
// conf.set("dfs.permissions.enabled", "false");
FileSystem fs = FileSystem.get(conf);
DistributedFileSystem dfs = (DistributedFileSystem)fs;
DatanodeInfo[] dni = dfs.getDataNodeStats();
for (DatanodeInfo datanodeInfo : dni) {
System.out.println("Capacity:"+datanodeInfo.getCapacity());
System.out.println("Remaining:"+datanodeInfo.getRemaining());
System.out.println("DatanodeReport:"+datanodeInfo.getDatanodeReport());
System.out.println("------------------------------------------");
}
}