hadoop的java.opts设置有误导致job setup失败

本文记录了一次Hadoop集群中Job频繁Setup失败的问题排查过程。通过调整mapred.child.java.opts参数,逐步精简垃圾回收相关选项,最终解决了作业运行失败的问题。
由于各台机器配置不同,想单独设置每个节点的mapred.child.java.opts参数,开始设置为
<property>
<name>mapred.child.java.opts</name>
<value>-Xms512m -Xmx512m -XX:+UseConcMarkSweepGC -XX:+UseCMSCompactAtFullCollection -XX:+CMSClassUnloadingEnabled -XX:CMSInitiatingOccupancyFraction=80 -XX:PretenureSizeThreshold</value>
</property>


节点重启无误,但发现提交的job每次都setup fail,只有一一排查,最后精简为
<property>
<name>mapred.child.java.opts</name>
<value>-Xms512m -Xmx512m -XX:+UseConcMarkSweepGC</value>
</property>

job才正确运行,估计有些参数不支持所致。
package myPageRank; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Mapper; import java.io.IOException; import java.util.StringTokenizer; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapreduce.Reducer; import java.io.IOException; import java.util.ArrayList; import org.apache.hadoop.conf.Configuration; import org.apache.hadoop.fs.Path; import org.apache.hadoop.io.IntWritable; import org.apache.hadoop.io.Text; import org.apache.hadoop.mapred.lib.ChainMapper; import org.apache.hadoop.mapreduce.Job; import org.apache.hadoop.mapreduce.lib.input.FileInputFormat; import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat; /** * @author tulie * @ceerte $(YEAR)-$(MONTH)-$(DAY)-$(TIME) */ /** * @author tulie * @ceerte $(YEAR)-$(MONTH)-$(DAY)-$(TIME) */ public class PRMapper extends Mapper<Object, Text, IntWritable, Text> { private IntWritable id; private String pr; private int count; private float average_pr; //重写map方法 public void map(Object key, Text value, Context context) { //构造一个用来解析 str 的 StringTokenizer 对象。java 默认的分隔符是空格("")、制表符(\t)、换行符(\n)、回车符(\r)。 StringTokenizer str = new StringTokenizer(value.toString()); //|1 6 2 4 5 if(str.hasMoreTokens())//返回是否还有分隔符 { id = new IntWritable(Integer.parseInt(str.nextToken()));//1 |6 2 4 5 }else{ return; } pr = str.nextToken();//返回从当前位置到下一个分隔符的字符串 1 6 |2 4 5 count = str.countTokens();//3 average_pr = Float.parseFloat(pr)/count; while(str.hasMoreTokens()) { try{ String nextId = str.nextToken();//1 6 2| 4 5 IntWritable linid = new IntWritable(Integer.parseInt(nextId)); //将网页向外链接的ID以“pr+得到贡献值”格式输出 Text avpr = new Text("pr" + average_pr); context.write(linid, avpr); // 将网页ID和PR值输出 Text ids = new Text("id" + nextId); context.write(id, ids); }catch(IOException e) { e.printStackTrace(); }catch (InterruptedException e) { e.printStackTrace(); } } } } /** * @author tulie * @ceerte $(YEAR)-$(MONTH)-$(DAY)-$(TIME) */ public class PRReducer extends Reducer<IntWritable, Text, IntWritable, Text> { //重写reduce方法 public void reduce(IntWritable key, Iterable<Text> values, Context context) { // 定义一个存储网页链接ID的队列 ArrayList<String> ids = new ArrayList<String>(); // 将所有的链接ID以String格式保存 String strid = " "; // 定义一个保存网页PR值的变量 float pr = 0; //遍历 System.out.println(key.get()); for(Text txt : values) { String str = txt.toString(); //判断value是贡献值还是向外部的链接 if (str.startsWith("pr")) { // 贡献值 pr += Float.parseFloat(str.substring(2)); System.out.println(pr); } else if (str.startsWith("id")) { // 链接id String id = str.substring(2); ids.add(id); } } pr = 0.85f*pr + 0.15f; // 得到所有链接ID的String形式 for (int i = 0; i < ids.size(); i++) { strid += ids.get(i) + " "; } // 组合pr+lianjie成原文件的格式类型 String strpr = String.format("%.5f", pr); String result = strpr + strid; try { context.write(key, new Text(result)); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } } } (为我修改错误给出完整代码)
最新发布
10-22
java.lang.UnsatisfiedLinkError: org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Ljava/lang/String;I)Z at org.apache.hadoop.io.nativeio.NativeIO$Windows.access0(Native Method) at org.apache.hadoop.io.nativeio.NativeIO$Windows.access(NativeIO.java:645) at org.apache.hadoop.fs.FileUtil.canRead(FileUtil.java:1230) at org.apache.hadoop.util.DiskChecker.checkAccessByFileMethods(DiskChecker.java:160) at org.apache.hadoop.util.DiskChecker.checkDirInternal(DiskChecker.java:100) at org.apache.hadoop.util.DiskChecker.checkDir(DiskChecker.java:77) at org.apache.hadoop.util.BasicDiskValidator.checkStatus(BasicDiskValidator.java:32) at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.confChanged(LocalDirAllocator.java:331) at org.apache.hadoop.fs.LocalDirAllocator$AllocatorPerContext.getLocalPathForWrite(LocalDirAllocator.java:394) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:165) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:146) at org.apache.hadoop.fs.LocalDirAllocator.getLocalPathForWrite(LocalDirAllocator.java:130) at org.apache.hadoop.mapred.LocalDistributedCacheManager.setup(LocalDistributedCacheManager.java:123) at org.apache.hadoop.mapred.LocalJobRunner$Job.<init>(LocalJobRunner.java:172) at org.apache.hadoop.mapred.LocalJobRunner.submitJob(LocalJobRunner.java:794) at org.apache.hadoop.mapreduce.JobSubmitter.submitJobInternal(JobSubmitter.java:251) at org.apache.hadoop.mapreduce.Job$11.run(Job.java:1570) at org.apache.hadoop.mapreduce.Job$11.run(Job.java:1567) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:422) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1730) at org.apache.hadoop.mapreduce.Job.submit(Job.java:1567) at org.apache.hadoop.mapreduce.Job.waitForCompletion(Job.java:1588) at edu.imu.mapreduce.WordCount.run(WordCount.java:62) at edu.imu.m
07-03
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