Post upgrade to 1.379 we are experiencing increased ocurrances of dead executors on our slave systems. Prior to this release we had never encountered a dead executor on any system, master or slave. Immediately after deploying the 1.379 WAR, 6 executors spread out among a variety of slave platforms (Linux, WinXP 32bit, Win2k8 64bit) died. Today one more died on a Linux slave. Restarting Hudson clears out the dead executors, but disconnecting and reconnecting the slaves does not. I have not tried rebooting the slaves themselves yet. The stack trace below has consistently been the output associated with the dead executors.

java.lang.AbstractMethodError
at hudson.model.Executor.getEstimatedRemainingTimeMillis(Executor.java:340)
at hudson.model.queue.LoadPredictor$CurrentlyRunningTasks.predict(LoadPredictor.java:77)
at hudson.model.queue.MappingWorksheet.(MappingWorksheet.java:303)
at hudson.model.Queue.pop(Queue.java:753)
at hudson.model.Executor.grabJob(Executor.java:175)
at hudson.model.Executor.run(Executor.java:113)