void _pickInitial() throws MongoException {
if (_curAddress != null) return;
// we need to just get a server to query for ismaster
_pickCurrent();
try {
_logger.info("current address beginning of _pickInitial: " + _curAddress);
DBObject im = isMasterCmd();
if (_isMaster(im)) return;
synchronized (_allHosts) {
Collections.shuffle(_allHosts);
for (ServerAddress a : _allHosts) {
if (_curAddress == a) continue;
_logger.info("remote [" + _curAddress + "] -> [" + a + "]");
_set(a);
im = isMasterCmd();
if (_isMaster(im)) return;
_logger.severe("switched to: " + a + " but isn't master");
}
throw new MongoException("can't find master");
}
} catch (Exception e) {
_logger.log(Level.SEVERE, "can't pick initial master, using random one", e);
}
}
/**
* A TaskTracker wants to know the physical locations of completed, but not yet closed, tasks.
* This exists so the reduce task thread can locate map task outputs.
*/
public synchronized MapOutputLocation[] locateMapOutputs(
String taskId, String[][] mapTasksNeeded) {
ArrayList v = new ArrayList();
for (int i = 0; i < mapTasksNeeded.length; i++) {
for (int j = 0; j < mapTasksNeeded[i].length; j++) {
TaskInProgress tip = (TaskInProgress) taskidToTIPMap.get(mapTasksNeeded[i][j]);
if (tip != null && tip.isComplete(mapTasksNeeded[i][j])) {
String trackerId = (String) taskidToTrackerMap.get(mapTasksNeeded[i][j]);
TaskTrackerStatus tracker;
synchronized (taskTrackers) {
tracker = (TaskTrackerStatus) taskTrackers.get(trackerId);
}
v.add(new MapOutputLocation(mapTasksNeeded[i][j], tracker.getHost(), tracker.getPort()));
break;
}
}
}
// randomly shuffle results to load-balance map output requests
Collections.shuffle(v);
return (MapOutputLocation[]) v.toArray(new MapOutputLocation[v.size()]);
}
private void _pickCurrent() throws MongoException {
if (_allHosts == null)
throw new MongoException(
"got master/slave issue but not in master/slave mode on the client side");
synchronized (_allHosts) {
Collections.shuffle(_allHosts);
for (int i = 0; i < _allHosts.size(); i++) {
ServerAddress a = _allHosts.get(i);
if (a == _curAddress) continue;
if (_curAddress != null) {
_logger.info("switching from [" + _curAddress + "] to [" + a + "]");
}
_set(a);
return;
}
}
throw new MongoException("couldn't find a new host to swtich too");
}