"joc" wrote : Thanks for the incredibly fast reply, | | It has however raised a couple of other questions (as answers usually do :) ) | | When you say "A state transfer will time out unless it can acquire all locks on the oldest member" I assume this means that, in effect, this locks the whole cluster for the duration, as a transaction would need to update every member? |
No, it only locks the oldest member in the cluster (the coordinator). And it only locks it until we have copied its state. With streaming state transfer, where we will transfer the state in user-defined chunks of bytes, the tree will be locked until the transfer is done. anonymous wrote : | Are these locks only for writing, and you can still read? | We use read-locks on all nodes (Node.acquireAll()). In the future, we may simply acquire a WL on the root node, then we are guaranteed that no RL can have been held somewhere underneath us in the tree. anonymous wrote : | Assuming each node is locked individually (I assume a lot :) ), are all the locks kept for the duration of the transfer to the new member, or released as each node is transfered? | Until the state has been copied, or the state transfer is done (with streaming state transfer) anonymous wrote : | Would I be right in thinking that because of the locking, you should therefore only add 1 cache at a time or is there something to handle this case (so if we restarted all the servers in a cluster at the same time and the transfer took say 1 minute possibly all but the first one in might fail ? ) | If you restarted all nodes in a cluster at the same time, you'd potentially lose all in-memory state, unless the state is backed up by a shared CacheLoader, e.g. JDBCCacheLoader. anonymous wrote : | Will the transfer always be an all or nothing thing? (so its safe to assume if you can't read a node you *know* should be there - the transfer failed) or is there a better/proper way of telling it failed to get the state correctly? | Yes, all-or-nothing: if I cannot acquire a lock, the entire state transfer will fail View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3900255#3900255 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3900255 ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ JBoss-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/jboss-user
