Hello. I'm using hadoop 0.20.203.0 and fair scheduler. And I have some difficulties concerning the lack of multiple tasks per heartbeat in fair scheduler in version 0.20.203.0.
I've found fixed feature about it - https://issues.apache.org/jira/browse/MAPREDUCE-548. Fix version is <https://issues.apache.org/jira/browse/MAPREDUCE/fixforversion/12314045> 0.21.0. Version 0.20.203.0 was released several months later than 0.21.0, but as I can see this feature was not included in 0.20.203.0. I don't want to upgrade my hadoop to another version cause it may make me change lots of code. So the question is can I upgrade only fair scheduler jar without upgrading other libraries? I just need multiple tasks per heartbeat in fair scheduler. What's the easiest way to get it? I tried to upgrade fair scheduler jar to 1.0.2 but it didn't worked with the following exception: 2012-04-12 17:33:42,001 FATAL org.apache.hadoop.mapred.JobTracker: java.lang.NoClassDefFoundError: org/apache/hadoop/mapreduce/TaskType at org.apache.hadoop.mapred.FairScheduler.<clinit>(FairScheduler.java:64) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at org.apache.hadoop.conf.Configuration.getClassByName(Configuration.java:762) at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:807) at org.apache.hadoop.conf.Configuration.getClass(Configuration.java:833) at org.apache.hadoop.mapred.JobTracker.<init>(JobTracker.java:1573) at org.apache.hadoop.mapred.JobTracker.startTracker(JobTracker.java:183) at org.apache.hadoop.mapred.JobTracker.startTracker(JobTracker.java:175) at org.apache.hadoop.mapred.JobTracker.main(JobTracker.java:3702) Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.mapreduce.TaskType at java.net.URLClassLoader$1.run(URLClassLoader.java:202) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:190) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:247) ... 10 more 2012-04-12 17:33:42,002 INFO org.apache.hadoop.mapred.JobTracker: SHUTDOWN_MSG:
