When doing a HotRod RemoteCache.keySet(); call on a DIST Cache with <compatibility enabled="true"/>, the BulkUtil.getAllKeys() M/R task on the server-side will throw a ClassCastException:

10:44:13,965 ERROR [org.infinispan.server.hotrod.HotRodDecoder] (HotRodServerWorker-3) ISPN005009: Unexpected error before any request parameters read: org.infinispan.commons.CacheException: java.util.concurrent.ExecutionException: java.lang.ClassCastException: java.lang.String cannot be cast to [B
at org.infinispan.distexec.mapreduce.MapReduceTask.execute(MapReduceTask.java:360) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceTask.execute(MapReduceTask.java:634) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.server.hotrod.util.BulkUtil.getAllKeys(BulkUtil.java:36) [infinispan-server-hotrod-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.server.hotrod.AbstractEncoder1x.writeResponse(AbstractEncoder1x.scala:111) [infinispan-server-hotrod-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.server.hotrod.HotRodEncoder.encode(HotRodEncoder.scala:47) [infinispan-server-hotrod-6.0.0.Final.jar:6.0.0.Final]
at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.doEncode(OneToOneEncoder.java:66) [netty-3.6.6.Final.jar:]
at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.handleDownstream(OneToOneEncoder.java:59) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.Channels.write(Channels.java:704) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.Channels.write(Channels.java:671) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.AbstractChannel.write(AbstractChannel.java:248) [netty-3.6.6.Final.jar:]
at org.infinispan.server.core.AbstractProtocolDecoder.writeResponse(AbstractProtocolDecoder.scala:163) [infinispan-server-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.server.hotrod.HotRodDecoder.customDecodeKey(HotRodDecoder.scala:138) [infinispan-server-hotrod-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.server.core.AbstractProtocolDecoder.decodeKey(AbstractProtocolDecoder.scala:105) [infinispan-server-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.server.core.AbstractProtocolDecoder.decode(AbstractProtocolDecoder.scala:53) [infinispan-server-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.server.core.AbstractProtocolDecoder.decode(AbstractProtocolDecoder.scala:29) [infinispan-server-core-6.0.0.Final.jar:6.0.0.Final]
at org.jboss.netty.handler.codec.replay.ReplayingDecoder.callDecode(ReplayingDecoder.java:500) [netty-3.6.6.Final.jar:]
at org.jboss.netty.handler.codec.replay.ReplayingDecoder.messageReceived(ReplayingDecoder.java:435) [netty-3.6.6.Final.jar:]
at org.infinispan.server.core.AbstractProtocolDecoder.messageReceived(AbstractProtocolDecoder.scala:377) [infinispan-server-core-6.0.0.Final.jar:6.0.0.Final]
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:268) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:255) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.socket.nio.NioWorker.read(NioWorker.java:88) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.process(AbstractNioWorker.java:109) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.socket.nio.AbstractNioSelector.run(AbstractNioSelector.java:312) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.socket.nio.AbstractNioWorker.run(AbstractNioWorker.java:90) [netty-3.6.6.Final.jar:]
at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:178) [netty-3.6.6.Final.jar:]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_45]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_45]
at java.lang.Thread.run(Thread.java:744) [rt.jar:1.7.0_45]
Caused by: java.util.concurrent.ExecutionException: java.lang.ClassCastException: java.lang.String cannot be cast to [B
at java.util.concurrent.FutureTask.report(FutureTask.java:122) [rt.jar:1.7.0_45]
at java.util.concurrent.FutureTask.get(FutureTask.java:188) [rt.jar:1.7.0_45]
at org.infinispan.distexec.mapreduce.MapReduceTask$TaskPart.get(MapReduceTask.java:845) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceTask.executeMapPhaseWithLocalReduction(MapReduceTask.java:492) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceTask.execute(MapReduceTask.java:358) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
... 27 more
Caused by: java.lang.ClassCastException: java.lang.String cannot be cast to [B
at org.infinispan.server.hotrod.util.BulkUtil$KeyMapper.map(BulkUtil.java:40) [infinispan-server-hotrod-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceManagerImpl.map(MapReduceManagerImpl.java:181) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceManagerImpl.mapAndCombineForLocalReduction(MapReduceManagerImpl.java:89) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceTask$MapTaskPart.invokeMapCombineLocallyForLocalReduction(MapReduceTask.java:955) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceTask$MapTaskPart.access$300(MapReduceTask.java:894) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceTask$MapTaskPart$2.call(MapReduceTask.java:926) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at org.infinispan.distexec.mapreduce.MapReduceTask$MapTaskPart$2.call(MapReduceTask.java:922) [infinispan-core-6.0.0.Final.jar:6.0.0.Final]
at java.util.concurrent.FutureTask.run(FutureTask.java:262) [rt.jar:1.7.0_45]
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [rt.jar:1.7.0_45]
at java.util.concurrent.FutureTask.run(FutureTask.java:262) [rt.jar:1.7.0_45]
... 3 more