Include a "region" column in the nodes table. Peers in different regions

must use the public host name to connect to each other.  This is in support
of adding servers in different EC2 regions to Spiral Knights (it's looking
like this solution will be less complicated than trying to create a
cross-region shared DNS system).


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@6722 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/main/java/com/threerings/presents/peer/server/PeerManager.java

@@ -288,8 +288,36 @@ public abstract class PeerManager
      * @param nodeNamespace The namespace for nodes to peer with. This node will connect to other
      * nodes with the same prefix from the NODES table.
      */
-    public void init (String nodeName, String sharedSecret,
-                      String hostName, String publicHostName, int port, String nodeNamespace)
+    public void init (
+        String nodeName, String sharedSecret, String hostName,
+        String publicHostName, int port, String nodeNamespace)
+    {
+        init(nodeName, sharedSecret, hostName, publicHostName, null, port, nodeNamespace);
+    }
+
+    /**
+     * Initializes this peer manager and initiates the process of connecting to its peer nodes.
+     * This will also reconfigure the ConnectionManager and ClientManager with peer related bits,
+     * so this should not be called until <em>after</em> the main server has set up its client
+     * factory and authenticator.
+     *
+     * @param nodeName this node's unique name.
+     * @param sharedSecret a shared secret used to allow the peers to authenticate with one
+     * another.
+     * @param hostName the DNS name of the server running this node.
+     * @param publicHostName if non-null, a separate public DNS hostname by which the node is to
+     * be known to normal clients (we may want inter-peer communication to take place over a
+     * different network than the communication between real clients and the various peer
+     * servers).
+     * @param region the region in which the node lives, which may be null.  Nodes in different
+     * regions must connect to each other through the public host name.
+     * @param port the port on which other nodes should connect to us.
+     * @param nodeNamespace The namespace for nodes to peer with. This node will connect to other
+     * nodes with the same prefix from the NODES table.
+     */
+    public void init (
+        String nodeName, String sharedSecret, String hostName, String publicHostName,
+        String region, int port, String nodeNamespace)
     {
         _nodeNamespace = nodeNamespace;
         _nodeName = nodeName;
@@ -313,7 +341,8 @@ public abstract class PeerManager
 
         // register ourselves with the node table
         _self = new NodeRecord(
-            _nodeName, hostName, (publicHostName == null) ? hostName : publicHostName, port);
+            _nodeName, hostName, (publicHostName == null) ? hostName : publicHostName,
+            region, port);
         _invoker.postUnit(new WriteOnlyUnit("registerNode(" + _self + ")") {
             @Override
             public void invokePersist () throws Exception {
@@ -1254,6 +1283,14 @@ public abstract class PeerManager
         return new PeerCreds(_nodeName, _sharedSecret);
     }
 
+    /**
+     * Returns the region in which the local node exists.
+     */
+    protected String getRegion ()
+    {
+        return _self.region;
+    }
+
     /**
      * Called when we hear about a client logging on to another node.
      */

src/main/java/com/threerings/presents/peer/server/PeerNode.java

@@ -127,7 +127,9 @@ public class PeerNode
     public void refresh (NodeRecord record)
     {
         // if the hostname of this node changed, kill our existing client and connect anew
-        if (!record.hostName.equals(_record.hostName) && _client.isActive()) {
+        String region = _peermgr.getRegion();
+        String hostName = record.getPeerHostName(region);
+        if (!hostName.equals(_record.getPeerHostName(region)) && _client.isActive()) {
             _client.logoff(false);
         }
 
@@ -149,7 +151,7 @@ public class PeerNode
 
         // otherwise configure our client with the right bits and logon
         _client.setCredentials(_peermgr.createCreds());
-        _client.setServer(_record.hostName, new int[] { _record.port });
+        _client.setServer(hostName, new int[] { _record.port });
         _client.logon();
         _lastConnectStamp = System.currentTimeMillis();
     }

src/main/java/com/threerings/presents/peer/server/persist/NodeRecord.java

@@ -23,6 +23,8 @@ package com.threerings.presents.peer.server.persist;
 
 import java.sql.Timestamp;
 
+import com.google.common.base.Objects;
+
 import com.samskivert.util.StringUtil;
 
 import com.samskivert.depot.Key;
@@ -43,6 +45,7 @@ public class NodeRecord extends PersistentRecord
     public static final ColumnExp<String> NODE_NAME = colexp(_R, "nodeName");
     public static final ColumnExp<String> HOST_NAME = colexp(_R, "hostName");
     public static final ColumnExp<String> PUBLIC_HOST_NAME = colexp(_R, "publicHostName");
+    public static final ColumnExp<String> REGION = colexp(_R, "region");
     public static final ColumnExp<Integer> PORT = colexp(_R, "port");
     public static final ColumnExp<Timestamp> LAST_UPDATED = colexp(_R, "lastUpdated");
     public static final ColumnExp<Boolean> SHUTDOWN = colexp(_R, "shutdown");
@@ -50,7 +53,7 @@ public class NodeRecord extends PersistentRecord
 
     /** Increment this value if you modify the definition of this persistent
      * object in a way that will result in a change to its SQL counterpart. */
-    public static final int SCHEMA_VERSION = 2;
+    public static final int SCHEMA_VERSION = 3;
 
     /** The unique name assigned to this node. */
     @Id
@@ -65,6 +68,11 @@ public class NodeRecord extends PersistentRecord
     @Column(name="PUBLIC_HOST_NAME", length=64)
     public String publicHostName;
 
+    /** The region in which the node exists.  Nodes in different regions must connect through the
+     * public host name. */
+    @Column(name="REGION", length=64, nullable=true)
+    public String region;
+
     /** The port on which to connect to this node. */
     @Column(name="PORT")
     public int port;
@@ -83,11 +91,13 @@ public class NodeRecord extends PersistentRecord
     }
 
     /** Creates a record for the specified node. */
-    public NodeRecord (String nodeName, String hostName, String publicHostName, int port)
+    public NodeRecord (
+        String nodeName, String hostName, String publicHostName, String region, int port)
     {
         this.nodeName = nodeName;
         this.hostName = hostName;
         this.publicHostName = publicHostName;
+        this.region = region;
         this.port = port;
     }
 
@@ -97,6 +107,14 @@ public class NodeRecord extends PersistentRecord
         this.nodeName = nodeName;
     }
 
+    /**
+     * Returns the host name to which peers in the specified region should connect.
+     */
+    public String getPeerHostName (String region)
+    {
+        return Objects.equal(this.region, region) ? hostName : publicHostName;
+    }
+
     @Override
     public String toString ()
     {