我正在嘗試收集各種有效的tasttrackers的指標,但它會引發異常如何收集hadoop tasktracker狀態?
不知道爲什麼?
for(String s: jc.getClusterStatus(true).getActiveTrackerNames()){
System.out.println("tt "+s);
System.out.println(""+ new org.apache.hadoop.mapreduce.server.jobtracker.TaskTracker(s).getAvailableSlots(TaskType.MAP)); }
輸出
提示符$ /installs/hadoop-0.20.2//bin/hadoop罐子的tools.jar tools.MetaInfo
TT tracker_10.0.0.6:本地主機/ 127.0.0.1 :53256 java.lang.NullPointerException at org.apache.hadoop.mapreduce.server.jobtracker.TaskTracker.getAvailableSlots(TaskTracker.java:90)at tools.MetaInfo。(MetaInfo.java:44)at tools.MetaInfo.main(MetaInfo .java:51)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)at sun.reflect.DelegatingMethodAccessorImpl.invoke(Delegat ingMethodAccessorImpl.java:25)at java.lang.reflect.Method.invoke(Method.java:597)at org.apache.hadoop.util.RunJar.main(RunJar.java:186)jabir:CompareHdfs jabir.ahmed $
不知道爲什麼它不顯示可用插槽,但顯示錯誤