我正在尝试实现 reduce side join ,并使用 mapfile reader 查找分布式缓存,但在 stderr 中检查时它没有查找值,它显示以下错误,lookupfile 文件已经存在于 hdfs 中,并且似乎如标准输出所示正确加载到缓存中。
java.lang.IllegalArgumentException: Wrong FS: file:/app/hadoop/tmp/mapred/local/taskTracker/distcache/-8118663285704962921_-1196516983_170706299/localhost/input/delivery_status/DeliveryStatusCodes/data, expected: hdfs://localhost:9000 at org.apache.hadoop.fs.FileSystem.checkPath(FileSystem.java:390) at org.apache.hadoop.hdfs.DistributedFileSystem.getPathName(DistributedFileSystem.java:140) at org.apache.hadoop.hdfs.DistributedFileSystem.getFileStatus(DistributedFileSystem.java:554) at org.apache.hadoop.fs.FileSystem.getLength(FileSystem.java:816) at org.apache.hadoop.io.SequenceFile$Reader.(SequenceFile.java:1479) at org.apache.hadoop.io.SequenceFile$Reader.(SequenceFile.java:1474) at org.apache.hadoop.io.MapFile$Reader.createDataFileReader(MapFile.java:302) at org.apache.hadoop.io.MapFile$Reader.open(MapFile.java:284) at org.apache.hadoop.io.MapFile$Reader.(MapFile.java:273) at org.apache.hadoop.io.MapFile$Reader.(MapFile.java:260) at org.apache.hadoop.io.MapFile$Reader.(MapFile.java:253) at mr_poc.reducerrsj.initializeDepartmentsMap(reducerrsj.java:59) at mr_poc.reducerrsj.setup(reducerrsj.java:42) at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:174) at org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:649) at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:418) at org.apache.hadoop.mapred.Child$4.run(Child.java:255) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:416) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1190) at org.apache.hadoop.mapred.Child.main(Child.java:249) java.lang.NullPointerException at mr_poc.reducerrsj.buildOutputValue(reducerrsj.java:83) at mr_poc.reducerrsj.reduce(reducerrsj.java:127) at mr_poc.reducerrsj.reduce(reducerrsj.java:1) at org.apache.hadoop.mapreduce.Reducer.run(Reducer.java:177) at org.apache.hadoop.mapred.ReduceTask.runNewReducer(ReduceTask.java:649) at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:418) at org.apache.hadoop.mapred.Child$4.run(Child.java:255) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:416) at org.apache.hadoop.security.
这是我的驱动代码,
package mr_poc;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;
import org.apache.hadoop.util.Tool;
import org.apache.hadoop.util.ToolRunner;
public class driverrsj extends Configured implements Tool{
@Override
public int run(String[] arg) throws Exception {
if(arg.length != 3)
{
System.out.printf("3 parameters are required for DriverRSJ- <Input Dir1> <Input Dir2> <Output Dir> \n");
return -1;
}
Job job = new Job(getConf());
Configuration conf = job.getConfiguration();
DistributedCache.addCacheFile(new URI("/input/delivery_status"), conf);
System.out.println("Cache : " + job.getConfiguration().get("mapred.cache.files"));
job.setJarByClass(driverrsj.class);
conf.setInt("cust_info", 1);
conf.setInt("status", 2);
StringBuilder inputPaths = new StringBuilder();
inputPaths.append(arg[0].toString()).append(",").append(arg[1].toString());
FileInputFormat.setInputPaths(job, inputPaths.toString());
FileOutputFormat.setOutputPath(job, new Path(arg[2]));
job.setJarByClass(driverrsj.class);
job.setMapperClass(mappperRSJ.class);
job.setReducerClass(reducerrsj.class);
job.setMapOutputKeyClass(CompositeKeyWritableRSJ.class);
job.setMapOutputValueClass(Text.class);
//job.setPartitionerClass(partinonrsj.class);
job.setSortComparatorClass(secondarysortcomp.class);
job.setGroupingComparatorClass(GroupingComparatorRSJ.class);
job.setNumReduceTasks(1);
job.setOutputKeyClass(NullWritable.class);
job.setOutputValueClass(Text.class);
boolean success =job.waitForCompletion(true);
return success? 0 : 1;
}
public static void main(String[] args) throws Exception{
int exitCode = ToolRunner.run(new Configuration(), new driverrsj(),args);
System.exit(exitCode);
}
}
这是我的reducer代码
包mr_poc;
import java.io.File;
import java.io.IOException;
import java.net.URI;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.filecache.DistributedCache;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.MapFile;
import org.apache.hadoop.io.NullWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Reducer;
public class reducerrsj extends Reducer<CompositeKeyWritableRSJ, Text, NullWritable, Text>{
StringBuilder reduceValueBuilder = new StringBuilder("");
NullWritable nullWritableKey = NullWritable.get();
Text reduceOutputValue = new Text("");
String strSeparator = ",";
private MapFile.Reader deptMapReader = null;
Text txtMapFileLookupKey = new Text();
Text txtMapFileLookupValue = new Text();
//Path[] cacheFilesLocal;
//Path[] eachPath;
@Override
protected void setup(Context context) throws IOException,InterruptedException {
Path[] cacheFiles = DistributedCache.getLocalCacheFiles(context.getConfiguration());
for ( Path eachPath : cacheFiles){
System.out.println(eachPath.toString());
System.out.println(eachPath.getName());
if(eachPath.getName().toString().contains("delivery_status"))
{
URI uriUncompressedFile = new File(eachPath.toString()+ "/DeliveryStatusCodes").toURI();
initializeDepartmentsMap(uriUncompressedFile, context);
}
}
}
//@SuppressWarnings("deprecation")
private void initializeDepartmentsMap(URI uriUncompressedFile, Context context)
throws IOException {
// {{
// Initialize the reader of the map file (side data)
Configuration conf = context.getConfiguration();
conf.addResource(new Path("/usr/local/hadoop-1.2.1/conf/core-site.xml"));
FileSystem dfs = FileSystem.get(conf);
try {
deptMapReader = new MapFile.Reader(dfs,uriUncompressedFile.toString(), context.getConfiguration());
} catch (Exception e) {
e.printStackTrace();
}
// }}
}
private StringBuilder buildOutputValue(CompositeKeyWritableRSJ key,
StringBuilder reduceValueBuilder, Text value) {
if (key.getsourceindex() == 2) {
String arrSalAttributes[] = value.toString().split(",");
txtMapFileLookupKey.set(arrSalAttributes[0].toString());
System.out.println("key=" + txtMapFileLookupKey);
try {
deptMapReader.get(txtMapFileLookupKey, txtMapFileLookupValue);
}
catch (Exception e) {
txtMapFileLookupValue.set("");
e.printStackTrace();
} finally {
txtMapFileLookupValue
.set((txtMapFileLookupValue.equals(null) || txtMapFileLookupValue
.equals("")) ? "NOT-FOUND"
: txtMapFileLookupValue.toString());
}
reduceValueBuilder.append(txtMapFileLookupValue.toString());
} else if(key.getsourceindex() == 1) {
String arrEmpAttributes[] = value.toString().split(",");
reduceValueBuilder.append(arrEmpAttributes[0].toString()).append(
strSeparator);
}
txtMapFileLookupKey.set("");
txtMapFileLookupValue.set("");
return reduceValueBuilder;
}
@Override
public void reduce(CompositeKeyWritableRSJ key, Iterable<Text> values,
Context context) throws IOException, InterruptedException {
for (Text value : values) {
buildOutputValue(key, reduceValueBuilder, value);
}
// Drop last comma, set value, and emit output
if (reduceValueBuilder.length() > 1) {
//reduceValueBuilder.setLength(reduceValueBuilder.length() - 1);
// Emit output
reduceOutputValue.set(reduceValueBuilder.toString());
context.write(nullWritableKey, reduceOutputValue);
} else {
System.out.println("Key=" + key.getjoinkey() + "src="
+ key.getsourceindex());
}
// Reset variables
reduceValueBuilder.setLength(0);
reduceOutputValue.set("");
}
@Override
protected void cleanup(Context context) throws IOException,
InterruptedException {
if(deptMapReader != null)
{
deptMapReader.close();
}
}
}
这是我的核心站点-Xml
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
<!-- Put site-specific property overrides in this file. -->
<configuration>
<property>
<name>hadoop.tmp.dir</name>
<value>/app/hadoop/tmp</value>
<description>A base for other temporary directories.</description>
</property>
<property>
<name>fs.default.name</name>
<value>hdfs://localhost:9000</value>
<description>The name of the default file system. A URI whose
scheme and authority determine the FileSystem implementation. The
uri's scheme determines the config property (fs.SCHEME.impl) naming
the FileSystem implementation class. The uri's authority is used to
determine the host, port, etc. for a filesystem.</description>
</property>
</configuration>
任何帮助将不胜感激。提前致谢!!!
最佳答案
我遇到了同样的问题,我通过添加
解决了这个问题FileSystem fs = FileSystem.get(new URI("hdfs://localhost:9000"),conf)
在驱动类中。
您必须从 java.net.URI
导入 URI
关于java.lang.IllegalArgumentException : Wrong FS: , 预期:hdfs://localhost:9000,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/23779976/