The port logic is a bit complex, but all encapsulated in
NettyServer.java (see below).
If nothing else is running on those ports and you really only have one
giraph worker per port you should be good to go. Can you look at the
logs for the worker that is trying to start a port other than base port
+ taskId?
int taskId = conf.getTaskPartition();
int numTasks = conf.getInt("mapred.map.tasks", 1);
// Number of workers + 1 for master
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 bindAttempts = 0;
final int maxIpcPortBindAttempts =
MAX_IPC_PORT_BIND_ATTEMPTS.get(conf);
final boolean failFirstPortBindingAttempt =
GiraphConstants.FAIL_FIRST_IPC_PORT_BIND_ATTEMPT.get(conf);
// Simple handling of port collisions on the same machine while
// preserving debugability from the port number alone.
// Round up the max number of workers to the next power of 10 and use
// it as a constant to increase the port number with.
while (bindAttempts < maxIpcPortBindAttempts) {
this.myAddress = new InetSocketAddress(localHostname, bindPort);
if (failFirstPortBindingAttempt && bindAttempts == 0) {
if (LOG.isInfoEnabled()) {
LOG.info("start: Intentionally fail first " +
"binding attempt as giraph.failFirstIpcPortBindAttempt " +
"is true, port " + bindPort);
}
++bindAttempts;
bindPort += portIncrementConstant;
continue;
}
try {
Channel ch = bootstrap.bind(myAddress);
accepted.add(ch);
break;
} catch (ChannelException e) {
LOG.warn("start: Likely failed to bind on attempt " +
bindAttempts + " to port " + bindPort, e);
++bindAttempts;
bindPort += portIncrementConstant;
}
}
if (bindAttempts == maxIpcPortBindAttempts || myAddress == null) {
throw new IllegalStateException(
"start: Failed to start NettyServer with " +
bindAttempts + " attempts");
}
On 11/22/13 9:15 AM, Larry Compton wrote:
My teammates and I are running Giraph on a cluster where a firewall is
configured on each compute node. We had 100 ports opened on the
compute nodes, which we thought would be more than enough to
accommodate a large number of workers. However, we're unable to go
beyond about 90 workers with our Giraph jobs, due to Netty ports being
allocated outside of the range (30000-30100). We're not sure why this
is happening. We shouldn't be running more than one worker per compute
node, so we were assuming that only port 30000 would be used, but
we're routinely seeing Giraph try to use ports greater than 30100 when
we request close to 100 workers. This leads us to believe that a
simple one up numbering scheme is being used that doesn't take the
host into consideration, although this is only speculation.
Is there a way around this problem? Our system admins understandably
balked at opening 1000 ports.
Larry
