I've updated to the latest one (apache-activemq-5.9-20130711.133644-74- bin.tar.gz) but with no success.
I've changed only three points in the vanilla activemq.xml: a) I've commented out the inclusion of jetty at the bottom of the file. (I don't need the web-app) b) I've changed the brokerName to www01, www03 and www03 (each in the related file) c) I've pasted in (and replaced the default one) the <persistenceAdapter>...</persistenceAdapter> part. I've turned on logging thats what happend after restarting the second node: 2013-07-16 06:58:36,585 | DEBUG | Got ping response for sessionid: 0x33fe1f2d41f0004 after 9ms | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:37,919 | DEBUG | Got ping response for sessionid: 0x33fe1f2d41f0004 after 8ms | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:39,171 | DEBUG | Got notification sessionid:0x33fe1f2d41f0004 | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:39,171 | DEBUG | Got WatchedEvent state:SyncConnected type:NodeDeleted path:/activemq/leveldb-stores/00000000054 for sessionid 0x33fe1f2d41f0004 | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:39,171 | DEBUG | [/activemq/leveldb-stores/00000000054] [ZooKeeperTreeTracker@40b20d52] [Thread[main-EventThread,5,main]] treeWatcher: type=NodeDeleted, state=SyncConnected | org.linkedin.zookeeper.tracker.ZooKeeperTreeTracker | main-EventThread 2013-07-16 06:58:39,171 | DEBUG | Got notification sessionid:0x33fe1f2d41f0004 | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:39,171 | DEBUG | [/activemq/leveldb-stores/00000000054] [ZooKeeperTreeTracker@40b20d52] [Thread[main-EventThread,5,main]] stop tracking node | org.linkedin.zookeeper.tracker.ZooKeeperTreeTracker | main- EventThread 2013-07-16 06:58:39,171 | DEBUG | Got WatchedEvent state:SyncConnected type:NodeChildrenChanged path:/activemq/leveldb-stores for sessionid 0x33fe1f2d41f0004 | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:39,181 | DEBUG | Reading reply sessionid:0x33fe1f2d41f0004, packet:: clientPath:null serverPath:null finished:false header:: 17,4 replyHeader:: 17,34359738434,-101 request:: '/activemq/leveldb-stores/00000000054,T response:: | org.apache.zookeeper.ClientCnxn | main-SendThread(109.73.50.78:2181) 2013-07-16 06:58:39,181 | DEBUG | [/activemq/leveldb-stores/00000000054] [ZooKeeperTreeTracker@40b20d52] [Thread[main-EventThread,5,main]] *no such node* | org.linkedin.zookeeper.tracker.ZooKeeperTreeTracker | main- EventThread 2013-07-16 06:58:39,182 | INFO | Not enough cluster members connected to elect a master. | org.apache.activemq.leveldb.replicated.MasterElector | main- EventThread 2013-07-16 06:58:39,183 | DEBUG | [/activemq/leveldb-stores] [ZooKeeperTreeTracker@40b20d52] [Thread[main-EventThread,5,main]] treeWatcher: type=NodeChildrenChanged, state=SyncConnected | org.linkedin.zookeeper.tracker.ZooKeeperTreeTracker | main-EventThread 2013-07-16 06:58:39,192 | DEBUG | Reading reply sessionid:0x33fe1f2d41f0004, packet:: clientPath:null serverPath:null finished:false header:: 18,4 replyHeader:: 18,34359738434,0 request:: '/activemq/leveldb-stores,T response:: ,s{21474836483,21474836483,1373541435591,1373541435591,0,111,0,0,0, 3,34359738434} | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:39,220 | DEBUG | Reading reply sessionid:0x33fe1f2d41f0004, packet:: clientPath:null serverPath:null finished:false header:: 19,12 replyHeader:: 19,34359738434,0 request:: '/activemq/leveldb-stores,T response:: v{'00000000055,'00000000056,'00000000044},s{21474836483,214748364 83,1373541435591,1373541435591,0,111,0,0,0,3,34359738434} | org.apache.zookeeper.ClientCnxn | main-SendThread(109.73.50.78:2181) 2013-07-16 06:58:39,220 | DEBUG | [/activemq/leveldb-stores] [ZooKeeperTreeTracker@40b20d52] [Thread[main-EventThread,5,main]] start tracking node zkTxId=34359738434 | org.linkedin.zookeeper.tracker.ZooKeeperTreeTracker | main-EventThread 2013-07-16 06:58:40,007 | DEBUG | Got notification sessionid:0x33fe1f2d41f0004 | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:40,008 | DEBUG | Got WatchedEvent state:SyncConnected type:NodeChildrenChanged path:/activemq/leveldb-stores for sessionid 0x33fe1f2d41f0004 | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:40,008 | DEBUG | [/activemq/leveldb-stores] [ZooKeeperTreeTracker@40b20d52] [Thread[main-EventThread,5,main]] treeWatcher: type=NodeChildrenChanged, state=SyncConnected | org.linkedin.zookeeper.tracker.ZooKeeperTreeTracker | main-EventThread 2013-07-16 06:58:40,019 | DEBUG | Reading reply sessionid:0x33fe1f2d41f0004, packet:: clientPath:null serverPath:null finished:false header:: 20,4 replyHeader:: 20,34359738436,0 request:: '/activemq/leveldb-stores,T response:: ,s{21474836483,21474836483,1373541435591,1373541435591,0,112,0,0,0, 4,34359738436} | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:40,030 | DEBUG | Reading reply sessionid:0x33fe1f2d41f0004, packet:: clientPath:null serverPath:null finished:false header:: 21,12 replyHeader:: 21,34359738436,0 request:: '/activemq/leveldb-stores,T response:: v{'00000000055,'00000000056,'00000000057,'00000000044},s{214748364 83,21474836483,1373541435591,1373541435591,0,112,0,0,0,4,343597384 36} | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:40,041 | DEBUG | Reading reply sessionid:0x33fe1f2d41f0004, packet:: clientPath:null serverPath:null finished:false header:: 22,4 replyHeader:: 22,34359738436,0 request:: '/activemq/leveldb-stores/00000000057,T response:: #7b226964223a227777773033222c2261646472657373223a6e756c6c2c22 706f736974696f6e223a2d312c22656c6563746564223a6e756c6c7d,s{3435 9738436,34359738436,1373950722837,1373950722837,0,0,0,23415413870 3691781,58,0,34359738436} | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) 2013-07-16 06:58:40,041 | DEBUG | [/activemq/leveldb-stores/00000000057] [ZooKeeperTreeTracker@40b20d52] [Thread[main-EventThread,5,main]] start tracking leaf node zkTxId=34359738436 | org.linkedin.zookeeper.tracker.ZooKeeperTreeTracker | main-EventThread 2013-07-16 06:58:40,041 | DEBUG | [/activemq/leveldb-stores] [ZooKeeperTreeTracker@40b20d52] [Thread[main-EventThread,5,main]] start tracking node zkTxId=34359738436 | org.linkedin.zookeeper.tracker.ZooKeeperTreeTracker | main-EventThread 2013-07-16 06:58:40,042 | INFO | Not enough cluster members connected to elect a master. | org.apache.activemq.leveldb.replicated.MasterElector | main- EventThread 2013-07-16 06:58:41,374 | DEBUG | Got ping response for sessionid: 0x33fe1f2d41f0004 after 8ms | org.apache.zookeeper.ClientCnxn | main- SendThread(109.73.50.78:2181) And thats what happening after I've got restarted the third one.