While the node 192.168.252.61 was in the process of decommissioning I see this error in two other nodes:
INFO [Timer-1] 2010-05-18 06:01:12,048 Gossiper.java (line 179) InetAddress /192.168.252.62 is now dead. INFO [GMFD:1] 2010-05-18 06:04:00,189 Gossiper.java (line 568) InetAddress /192.168.252.62 is now UP INFO [Timer-1] 2010-05-18 06:11:45,311 Gossiper.java (line 401) FatClient / 192.168.252.61 has been silent for 3600000ms, removing from gossip ERROR [Timer-1] 2010-05-18 06:11:45,315 CassandraDaemon.java (line 88) Fatal exception in thread Thread[Timer-1,5,main] java.lang.RuntimeException: java.util.ConcurrentModificationException at org.apache.cassandra.gms.Gossiper$GossipTimerTask.run(Gossiper.java:97) at java.util.TimerThread.mainLoop(Timer.java:512) at java.util.TimerThread.run(Timer.java:462) Caused by: java.util.ConcurrentModificationException at java.util.Hashtable$Enumerator.next(Hashtable.java:1031) at org.apache.cassandra.gms.Gossiper.doStatusCheck(Gossiper.java:382) at org.apache.cassandra.gms.Gossiper$GossipTimerTask.run(Gossiper.java:91) ... 2 more .61 is the decommissioned node. .62 was under load (streams transferred to it from .61) I simply ran nodetool decommission on the 61 node and then (after an hour, I guess) I saw this error in two other live nodes. Does this ring any bell? It's either a bug, or that I wasn't running decommission correctly...