private DataNodeIdentifier pickHeaviestLoad(DataNodeIdentifier otherNode) {
DataNodeIdentifier replacementNode = null;
PriorityBlockingQueue<DataNodeStatusPair> invertedStatusQueue =
new PriorityBlockingQueue<DataNodeStatusPair>(
datanodeStatuses.size(),
new Comparator<DataNodeStatusPair>() {
public int compare(DataNodeStatusPair a, DataNodeStatusPair b) {
return -1 * a.compareTo(b);
}
});
for (DataNodeStatusPair each : datanodeStatuses) {
invertedStatusQueue.put(each);
}
while (replacementNode == null) {
DataNodeStatusPair next = invertedStatusQueue.poll();
DataNodeIdentifier nextId = next.getIdentifier();
if (!nextId.equals(otherNode)) {
replacementNode = nextId;
}
}
return replacementNode;
}
private DataNodeIdentifier pickReplacement(
SegmentGroup affectedGroup, DataNodeIdentifier oldNode) {
DataNodeIdentifier replacementNode = null;
List<DataNodeStatusPair> removedPairs = new ArrayList<DataNodeStatusPair>();
while (replacementNode == null) {
DataNodeStatusPair next = datanodeStatuses.poll();
removedPairs.add(next);
DataNodeIdentifier nextId = next.getIdentifier();
if (!nextId.equals(oldNode) && !affectedGroup.isMember(nextId)) {
replacementNode = nextId;
}
}
for (DataNodeStatusPair each : removedPairs) {
datanodeStatuses.add(each);
}
return replacementNode;
}
private void updateStatus(DataNodeIdentifier oldNode, DataNodeIdentifier replacementNode) {
int segmentsPerSegmentGroup = coordinator.getSegmentsPerSegmentGroup();
DataNodeStatusPair oldPair = null;
DataNodeStatusPair newPair = null;
for (DataNodeStatusPair eachPair : datanodeStatuses) {
if (oldNode.equals(eachPair.getIdentifier())) {
oldPair = eachPair;
} else if (replacementNode.equals(eachPair.getIdentifier())) {
newPair = eachPair;
}
}
oldPair.getStatus().addStoredSegments(-1 * segmentsPerSegmentGroup);
newPair.getStatus().addStoredSegments(segmentsPerSegmentGroup);
datanodeStatuses.remove(oldPair);
datanodeStatuses.remove(newPair);
datanodeStatuses.add(oldPair);
datanodeStatuses.add(newPair);
}