1 of 5 executors on Slave died. We could only resolve this by restarting the Master.

Exception in thread "Executor #2 for Slave_8" java.lang.IndexOutOfBoundsException: Index: 5, Size: 5
at java.util.ArrayList.RangeCheck(ArrayList.java:547)
at java.util.ArrayList.get(ArrayList.java:322)
at hudson.model.queue.MappingWorksheet$ReadOnlyList.get(MappingWorksheet.java:92)
at hudson.model.queue.MappingWorksheet$ExecutorChunk.execute(MappingWorksheet.java:140)
at hudson.model.queue.MappingWorksheet$ExecutorChunk.access$000(MappingWorksheet.java:100)
at hudson.model.queue.MappingWorksheet$Mapping.execute(MappingWorksheet.java:270)
at hudson.model.Queue.pop(Queue.java:761)
at hudson.model.Executor.grabJob(Executor.java:175)
at hudson.model.Executor.run(Executor.java:113)
Oct 15, 2010 3:01:24 AM hudson.remoting.Channel$ReaderThread run
SEVERE: I/O error in channel Slave_8
java.net.SocketException: socket closed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
at java.io.BufferedInputStream.read(BufferedInputStream.java:237)
at java.io.ObjectInputStream$PeekInputStream.peek(ObjectInputStream.java:2249)
at java.io.ObjectInputStream$BlockDataInputStream.peek(ObjectInputStream.java:2542)
at java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:2552)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1297)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
at hudson.remoting.Channel$ReaderThread.run(Channel.java:875)
Oct 15, 2010 3:01:24 AM hudson.TcpSlaveAgentListener$ConnectionHandler$1 onClosed
WARNING: Connection #54794 terminated
java.net.SocketException: socket closed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.read(SocketInputStream.java:129)
at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
at java.io.BufferedInputStream.read(BufferedInputStream.java:237)
at java.io.ObjectInputStream$PeekInputStream.peek(ObjectInputStream.java:2249)
at java.io.ObjectInputStream$BlockDataInputStream.peek(ObjectInputStream.java:2542)
at java.io.ObjectInputStream$BlockDataInputStream.peekByte(ObjectInputStream.java:2552)
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1297)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
at hudson.remoting.Channel$ReaderThread.run(Channel.java:875)