heap space was exhausted and issues occurred. In the end, one node in the cluster must have corrupted the data in the JDBC_PING table. From this point onward, our log is full of these (every two seconds):

2014 03 23 04:00:25#+0100#ERROR#org.jgroups.protocols.SMP_JDBC_PING##anonymous#Thread-15###Error java.io.EOFException: null
at java.io.DataInputStream.readUnsignedShort(DataInputStream.java:340)
at org.jgroups.stack.IpAddress.readFrom(IpAddress.java:226)
at org.jgroups.util.Util.readAddress(Util.java:929)
at org.jgroups.util.Util.readAddresses(Util.java:1047)
at org.jgroups.protocols.PingData.readFrom(PingData.java:163)
at org.jgroups.util.Util.streamableFromByteBuffer(Util.java:753)
at org.jgroups.protocols.Discovery.deserialize(Discovery.java:625)
at org.jgroups.protocols.JDBC_PING.readAll(JDBC_PING.java:221)
at org.jgroups.protocols.JDBC_PING.readAll(JDBC_PING.java:201)
at org.jgroups.protocols.FILE_PING.fetchClusterMembers(FILE_PING.java:68)
at org.jgroups.protocols.Discovery.sendDiscoveryRequest(Discovery.java:263)
at org.jgroups.protocols.Discovery.findMembers(Discovery.java:227)
at org.jgroups.protocols.Discovery.findInitialMembers(Discovery.java:208)
at org.jgroups.protocols.Discovery.down(Discovery.java:551)
at org.jgroups.protocols.FILE_PING.down(FILE_PING.java:101)
at org.jgroups.protocols.MERGE2.down(MERGE2.java:185)
at org.jgroups.protocols.FD_SOCK.down(FD_SOCK.java:363)
at org.jgroups.protocols.FD.down(FD.java:307)
at org.jgroups.protocols.VERIFY_SUSPECT.down(VERIFY_SUSPECT.java:84)
at org.jgroups.protocols.BARRIER.down(BARRIER.java:95)
at org.jgroups.protocols.pbcast.NAKACK2.down(NAKACK2.java:533)
at org.jgroups.protocols.UNICAST3.down(UNICAST3.java:575)
at org.jgroups.protocols.pbcast.STABLE.down(STABLE.java:347)
at org.jgroups.protocols.ENCRYPT.down(ENCRYPT.java:925)
at org.jgroups.protocols.pbcast.ClientGmsImpl.findInitialMembers(ClientGmsImpl.java:201)
at org.jgroups.protocols.pbcast.ClientGmsImpl.joinInternal(ClientGmsImpl.java:75)
at org.jgroups.protocols.pbcast.ClientGmsImpl.join(ClientGmsImpl.java:40)
at org.jgroups.protocols.pbcast.GMS.down(GMS.java:1052)
at org.jgroups.protocols.FlowControl.down(FlowControl.java:340)
at org.jgroups.protocols.FRAG2.down(FRAG2.java:136)
at org.jgroups.protocols.pbcast.STATE_TRANSFER.down(STATE_TRANSFER.java:237)
at org.jgroups.stack.ProtocolStack.down(ProtocolStack.java:1024)
at org.jgroups.JChannel.down(JChannel.java:760)
at org.jgroups.JChannel._connect(JChannel.java:538)
at org.jgroups.JChannel.connect(JChannel.java:290)
at org.jgroups.JChannel.connect(JChannel.java:275)
at com.sap.mobile.platform.server.cluster.service.impl.ClusterCommunicationsJGroupImpl.startCommunications(ClusterCommunicationsJGroupImpl.java:45)
at com.sap.mobile.platform.server.cluster.service.impl.ClusterCommunicationsJGroupImpl.<init>(ClusterCommunicationsJGroupImpl.java:59)
at com.sap.mobile.platform.server.cluster.service.impl.ClusterServiceImpl.run(ClusterServiceImpl.java:187)
at java.lang.Thread.run(Thread.java:791)