/**
* Creates the delegate connection factory.
*
* @return The delegate connection factory.
*/
private synchronized ConnectionFactory createDelegate() {
if (myDelegate == null) {
bootstrap();
if (myDelegate == null) {
LOG.warn("Could not bootstrap a connection to the MongoDB servers.");
throw new CannotConnectException(
"Could not bootstrap a connection to the MongoDB servers.");
}
}
return myDelegate;
}
/**
* Re-bootstraps the environment. Normally this method is only called once during the constructor
* of the factory to initialize the delegate but users can reset the delegate by manually invoking
* this method.
*
* <p>A bootstrap will issue one commands to the first working MongoDB process. The reply to the
* {@link IsMaster} command is used to detect connecting to a mongos <tt>process</tt> and by
* extension a Sharded configuration.
*
* <p>If not using a Sharded configuration then the server status is checked for a <tt>repl</tt>
* element. If present a Replication Set configuration is assumed.
*
* <p>If neither a Sharded or Replication Set is being used then a plain socket connection factory
* is used.
*/
protected void bootstrap() {
final SocketConnectionFactory socketFactory = createSocketFactory(myConfig);
socketFactory.setMetrics(myMetrics);
ProxiedConnectionFactory factory = socketFactory;
// Authentication has to be right on top of the physical
// connection.
if (myConfig.isAuthenticating()) {
factory = new AuthenticationConnectionFactory(factory, myConfig);
}
try {
// Use the socket factories cluster.
final Cluster cluster = socketFactory.getCluster();
for (final InetSocketAddress addr : myConfig.getServerAddresses()) {
Connection conn = null;
final FutureReplyCallback future = new FutureReplyCallback();
try {
conn = factory.connect(cluster.add(addr), myConfig);
conn.send(new IsMaster(), future);
final Reply reply = future.get();
// Close the connection now that we have the reply.
IOUtils.close(conn);
final List<Document> results = reply.getResults();
if (!results.isEmpty()) {
final Document doc = results.get(0);
if (isMongos(doc)) {
LOG.debug("Sharded bootstrap to {}.", addr);
cluster.clear(); // not needed.
myDelegate = bootstrapSharded(factory);
} else if (isReplicationSet(doc)) {
LOG.debug("Replica-set bootstrap to {}.", addr);
cluster.clear(); // not needed.
myDelegate = bootstrapReplicaSet(factory);
} else {
LOG.debug("Simple MongoDB bootstrap to {}.", addr);
myDelegate = factory;
}
factory = null; // Don't close.
return;
}
} catch (final IOException ioe) {
LOG.warn(ioe, "I/O error during bootstrap to {}.", addr);
} catch (final InterruptedException e) {
LOG.warn(e, "Interrupted during bootstrap to {}.", addr);
} catch (final ExecutionException e) {
LOG.warn(e, "Error during bootstrap to {}.", addr);
} finally {
IOUtils.close(
conn, Level.WARNING, "I/O error shutting down bootstrap connection to " + addr + ".");
}
}
} finally {
IOUtils.close(factory);
}
}