@SuppressWarnings("unchecked")
private List<Container> getResources() throws Exception {
int headRoom = getAvailableResources() != null
? getAvailableResources().getMemory() : 0;//first time it would be null
AllocateResponse response;
/*
* If contact with RM is lost, the AM will wait MR_AM_TO_RM_WAIT_INTERVAL_MS
* milliseconds before aborting. During this interval, AM will still try
* to contact the RM.
*/
try {
response = makeRemoteRequest();
// Reset retry count if no exception occurred.
retrystartTime = System.currentTimeMillis();
} catch (Exception e) {
// This can happen when the connection to the RM has gone down. Keep
// re-trying until the retryInterval has expired.
if (System.currentTimeMillis() - retrystartTime >= retryInterval) {
LOG.error("Could not contact RM after " + retryInterval + " milliseconds.");
eventHandler.handle(new JobEvent(this.getJob().getID(),
JobEventType.INTERNAL_ERROR));
throw new YarnRuntimeException("Could not contact RM after " +
retryInterval + " milliseconds.");
}
// Throw this up to the caller, which may decide to ignore it and
// continue to attempt to contact the RM.
throw e;
}
if (response.getAMCommand() != null) {
switch(response.getAMCommand()) {
case AM_RESYNC:
case AM_SHUTDOWN:
// This can happen if the RM has been restarted. If it is in that state,
// this application must clean itself up.
eventHandler.handle(new JobEvent(this.getJob().getID(),
JobEventType.JOB_AM_REBOOT));
throw new YarnRuntimeException("Resource Manager doesn't recognize AttemptId: " +
this.getContext().getApplicationID());
default:
String msg =
"Unhandled value of AMCommand: " + response.getAMCommand();
LOG.error(msg);
throw new YarnRuntimeException(msg);
}
}
int newHeadRoom = getAvailableResources() != null ? getAvailableResources().getMemory() : 0;
List<Container> newContainers = response.getAllocatedContainers();
// Setting NMTokens
if (response.getNMTokens() != null) {
for (NMToken nmToken : response.getNMTokens()) {
NMTokenCache.setNMToken(nmToken.getNodeId().toString(),
nmToken.getToken());
}
}
List<ContainerStatus> finishedContainers = response.getCompletedContainersStatuses();
if (newContainers.size() + finishedContainers.size() > 0 || headRoom != newHeadRoom) {
//something changed
recalculateReduceSchedule = true;
if (LOG.isDebugEnabled() && headRoom != newHeadRoom) {
LOG.debug("headroom=" + newHeadRoom);