GIRAPH-1248
closes #144
diff --git a/giraph-core/src/main/java/org/apache/giraph/comm/netty/NettyServer.java b/giraph-core/src/main/java/org/apache/giraph/comm/netty/NettyServer.java
index f44bf33..5cb1502 100644
--- a/giraph-core/src/main/java/org/apache/giraph/comm/netty/NettyServer.java
+++ b/giraph-core/src/main/java/org/apache/giraph/comm/netty/NettyServer.java
@@ -226,7 +226,18 @@
}
/**
- * Start the server with the appropriate port
+ * Start the server with the appropriate port.
+ *
+ * When the server starts, it will try to bind the port set in
+ * {@link GiraphConstants#IPC_INITIAL_PORT}. If the binding fails, we increase
+ * the port number and try again, until a maximum number of attempts,
+ * controlled by the {@link GiraphConstants#MAX_IPC_PORT_BIND_ATTEMPTS}
+ * option.
+ *
+ * If {@link GiraphConstants#IPC_INITIAL_PORT} is set to 0, then the server
+ * will bind port 0, which results in binding the first available port. In
+ * this case, every attempt will try to bind port 0.
+ *
*/
public void start() {
bootstrap = new ServerBootstrap();
@@ -352,7 +363,8 @@
int numServers = conf.getInt(GiraphConstants.MAX_WORKERS, numTasks) + 1;
int portIncrementConstant =
(int) Math.pow(10, Math.ceil(Math.log10(numServers)));
- int bindPort = GiraphConstants.IPC_INITIAL_PORT.get(conf) + taskId;
+ int initialPort = GiraphConstants.IPC_INITIAL_PORT.get(conf);
+ int bindPort = initialPort == 0 ? 0 : initialPort + taskId;
int bindAttempts = 0;
final int maxIpcPortBindAttempts = MAX_IPC_PORT_BIND_ATTEMPTS.get(conf);
final boolean failFirstPortBindingAttempt =
@@ -377,6 +389,15 @@
try {
ChannelFuture f = bootstrap.bind(myAddress).sync();
+
+ // If port 0 was specified, then the bound port will be the first port
+ // free, so we re-initialize myAddress to reflect the port that was
+ // actually bound.
+ if (this.myAddress.getPort() == 0) {
+ this.myAddress = new InetSocketAddress(localHostOrIp,
+ ((InetSocketAddress) f.channel().localAddress()).getPort());
+ }
+
accepted.add(f.channel());
break;
} catch (InterruptedException e) {
@@ -387,7 +408,8 @@
LOG.warn("start: Likely failed to bind on attempt " +
bindAttempts + " to port " + bindPort, e.getCause());
++bindAttempts;
- bindPort += portIncrementConstant;
+ // If initial port is set to 0, then keep trying to bind the same port
+ bindPort = (initialPort == 0) ? 0 : (bindPort + portIncrementConstant);
}
}
if (bindAttempts == maxIpcPortBindAttempts || myAddress == null) {
