/**
* Reconfigures the connected ViewNodes.
*
* <p>When a reconfiguration event happens, new ViewNodes may need to be added or old ones need to
* be removed from the current configuration. This method takes care that those operations are
* performed in the correct order and are executed in a thread-safe manner.
*
* @param bucket the bucket which has been rebalanced.
*/
public void reconfigure(Bucket bucket) {
reconfiguring = true;
try {
// get a new collection of addresses from the received config
HashSet<SocketAddress> newServerAddresses = new HashSet<SocketAddress>();
List<InetSocketAddress> newServers =
AddrUtil.getAddressesFromURL(bucket.getConfig().getCouchServers());
for (InetSocketAddress server : newServers) {
// add parsed address to our collections
newServerAddresses.add(server);
}
// split current nodes to "odd nodes" and "stay nodes"
ArrayList<ViewNode> shutdownNodes = new ArrayList<ViewNode>();
ArrayList<ViewNode> stayNodes = new ArrayList<ViewNode>();
ArrayList<InetSocketAddress> stayServers = new ArrayList<InetSocketAddress>();
wlock.lock();
try {
for (ViewNode current : couchNodes) {
if (newServerAddresses.contains(current.getSocketAddress())) {
stayNodes.add(current);
stayServers.add((InetSocketAddress) current.getSocketAddress());
} else {
shutdownNodes.add(current);
}
}
// prepare a collection of addresses for new nodes
newServers.removeAll(stayServers);
// create a collection of new nodes
List<ViewNode> newNodes = createConnections(newServers);
// merge stay nodes with new nodes
List<ViewNode> mergedNodes = new ArrayList<ViewNode>();
mergedNodes.addAll(stayNodes);
mergedNodes.addAll(newNodes);
couchNodes = mergedNodes;
} finally {
wlock.unlock();
}
// shutdown for the oddNodes
for (ViewNode qa : shutdownNodes) {
try {
qa.shutdown();
} catch (IOException e) {
getLogger().error("Error shutting down connection to " + qa.getSocketAddress());
}
}
} catch (IOException e) {
getLogger().error("Connection reconfiguration failed", e);
} finally {
reconfiguring = false;
}
}
/**
* Initiates the shutdown of all connected ViewNodes.
*
* @return false if a connection is already in progress, true otherwise.
* @throws IOException
*/
public boolean shutdown() throws IOException {
if (shutDown) {
getLogger().info("Suppressing duplicate attempt to shut down");
return false;
}
shutDown = true;
running = false;
List<ViewNode> nodesToRemove = new ArrayList<ViewNode>();
for (ViewNode node : couchNodes) {
if (node != null) {
String hostname = node.getSocketAddress().getHostName();
if (node.hasWriteOps()) {
getLogger().warn("Shutting down " + hostname + " with ops waiting to be written");
} else {
getLogger().info("Node " + hostname + " has no ops in the queue");
}
node.shutdown();
nodesToRemove.add(node);
}
}
for (ViewNode node : nodesToRemove) {
couchNodes.remove(node);
}
return true;
}
