A Reducer triggers the following exception:
08/11/05 08:58:50 INFO mapred.JobClient: Task Id : attempt_200811040110_0230_r_000008_1, Status : FAILED
java.lang.RuntimeException: Inconsistent state!!! JVM Manager reached an unstable state while reaping a JVM for task: attempt_200811040110_0230_r_000008_1 Number of active JVMs:2
JVMId jvm_200811040110_0230_r_-735233075 #Tasks ran: 0 Currently busy? true Currently running: attempt_200811040110_0230_r_000012_0
JVMId jvm_200811040110_0230_r_-1716942642 #Tasks ran: 0 Currently busy? true Currently running: attempt_200811040110_0230_r_000040_0
In the three reduce task attempts where this was observed, this was attempt _1. Attempt _0 had started and eventually switches to "SUCCEEDED." So I think this is happening only on speculatively-executed reduce task attempts. The reduce output (part-XXXXX) gets lost when this attempt fails, even though the other (earlier) attempt succeeded.