/**
* Creates a {@link BlockInfo} form a given {@link MasterBlockInfo}, by populating worker
* locations.
*
* @param masterBlockInfo the {@link MasterBlockInfo}
* @return a {@link BlockInfo} from a {@link MasterBlockInfo}. Populates worker locations
*/
@GuardedBy("masterBlockInfo")
private BlockInfo generateBlockInfo(MasterBlockInfo masterBlockInfo) {
// "Join" to get all the addresses of the workers.
List<BlockLocation> locations = new ArrayList<>();
List<MasterBlockLocation> blockLocations = masterBlockInfo.getBlockLocations();
// Sort the block locations by their alias ordinal in the master storage tier mapping
Collections.sort(
blockLocations,
new Comparator<MasterBlockLocation>() {
@Override
public int compare(MasterBlockLocation o1, MasterBlockLocation o2) {
return mGlobalStorageTierAssoc.getOrdinal(o1.getTierAlias())
- mGlobalStorageTierAssoc.getOrdinal(o2.getTierAlias());
}
});
for (MasterBlockLocation masterBlockLocation : blockLocations) {
MasterWorkerInfo workerInfo =
mWorkers.getFirstByField(ID_INDEX, masterBlockLocation.getWorkerId());
if (workerInfo != null) {
// worker metadata is intentionally not locked here because:
// - it would be an incorrect order (correct order is lock worker first, then block)
// - only uses getters of final variables
locations.add(
new BlockLocation()
.setWorkerId(masterBlockLocation.getWorkerId())
.setWorkerAddress(workerInfo.getWorkerAddress())
.setTierAlias(masterBlockLocation.getTierAlias()));
}
}
return new BlockInfo()
.setBlockId(masterBlockInfo.getBlockId())
.setLength(masterBlockInfo.getLength())
.setLocations(locations);
}
/**
* Updates the worker and block metadata for blocks removed from a worker.
*
* @param workerInfo The worker metadata object
* @param removedBlockIds A list of block ids removed from the worker
*/
@GuardedBy("workerInfo")
private void processWorkerRemovedBlocks(
MasterWorkerInfo workerInfo, Collection<Long> removedBlockIds) {
for (long removedBlockId : removedBlockIds) {
MasterBlockInfo block = mBlocks.get(removedBlockId);
// TODO(calvin): Investigate if this branching logic can be simplified.
if (block == null) {
// LOG.warn("Worker {} informs the removed block {}, but block metadata does not exist"
// + " on Master!", workerInfo.getId(), removedBlockId);
// TODO(pfxuan): [ALLUXIO-1804] should find a better way to handle the removed blocks.
// Ideally, the delete/free I/O flow should never reach this point. Because Master may
// update the block metadata only after receiving the acknowledgement from Workers.
workerInfo.removeBlock(removedBlockId);
// Continue to remove the remaining blocks.
continue;
}
synchronized (block) {
LOG.info("Block {} is removed on worker {}.", removedBlockId, workerInfo.getId());
workerInfo.removeBlock(block.getBlockId());
block.removeWorker(workerInfo.getId());
if (block.getNumLocations() == 0) {
mLostBlocks.add(removedBlockId);
}
}
}
}
/**
* Updates metadata when a worker registers with the master.
*
* @param workerId the worker id of the worker registering
* @param storageTiers a list of storage tier aliases in order of their position in the worker's
* hierarchy
* @param totalBytesOnTiers a mapping from storage tier alias to total bytes
* @param usedBytesOnTiers a mapping from storage tier alias to the used byes
* @param currentBlocksOnTiers a mapping from storage tier alias to a list of blocks
* @throws NoWorkerException if workerId cannot be found
*/
public void workerRegister(
long workerId,
List<String> storageTiers,
Map<String, Long> totalBytesOnTiers,
Map<String, Long> usedBytesOnTiers,
Map<String, List<Long>> currentBlocksOnTiers)
throws NoWorkerException {
MasterWorkerInfo worker = mWorkers.getFirstByField(ID_INDEX, workerId);
if (worker == null) {
throw new NoWorkerException(ExceptionMessage.NO_WORKER_FOUND.getMessage(workerId));
}
// Gather all blocks on this worker.
HashSet<Long> blocks = new HashSet<>();
for (List<Long> blockIds : currentBlocksOnTiers.values()) {
blocks.addAll(blockIds);
}
synchronized (worker) {
worker.updateLastUpdatedTimeMs();
// Detect any lost blocks on this worker.
Set<Long> removedBlocks =
worker.register(
mGlobalStorageTierAssoc, storageTiers, totalBytesOnTiers, usedBytesOnTiers, blocks);
processWorkerRemovedBlocks(worker, removedBlocks);
processWorkerAddedBlocks(worker, currentBlocksOnTiers);
}
LOG.info("registerWorker(): {}", worker);
}
/**
* Updates metadata when a worker periodically heartbeats with the master.
*
* @param workerId the worker id
* @param usedBytesOnTiers a mapping from tier alias to the used bytes
* @param removedBlockIds a list of block ids removed from this worker
* @param addedBlocksOnTiers a mapping from tier alias to the added blocks
* @return an optional command for the worker to execute
*/
public Command workerHeartbeat(
long workerId,
Map<String, Long> usedBytesOnTiers,
List<Long> removedBlockIds,
Map<String, List<Long>> addedBlocksOnTiers) {
MasterWorkerInfo worker = mWorkers.getFirstByField(ID_INDEX, workerId);
if (worker == null) {
LOG.warn("Could not find worker id: {} for heartbeat.", workerId);
return new Command(CommandType.Register, new ArrayList<Long>());
}
synchronized (worker) {
// Technically, 'worker' should be confirmed to still be in the data structure. Lost worker
// detection can remove it. However, we are intentionally ignoring this race, since the worker
// will just re-register regardless.
processWorkerRemovedBlocks(worker, removedBlockIds);
processWorkerAddedBlocks(worker, addedBlocksOnTiers);
worker.updateUsedBytes(usedBytesOnTiers);
worker.updateLastUpdatedTimeMs();
List<Long> toRemoveBlocks = worker.getToRemoveBlocks();
if (toRemoveBlocks.isEmpty()) {
return new Command(CommandType.Nothing, new ArrayList<Long>());
}
return new Command(CommandType.Free, toRemoveBlocks);
}
}
/**
* Returns a worker id for the given worker.
*
* @param workerNetAddress the worker {@link WorkerNetAddress}
* @return the worker id for this worker
*/
public long getWorkerId(WorkerNetAddress workerNetAddress) {
// TODO(gpang): This NetAddress cloned in case thrift re-uses the object. Does thrift re-use it?
MasterWorkerInfo existingWorker = mWorkers.getFirstByField(ADDRESS_INDEX, workerNetAddress);
if (existingWorker != null) {
// This worker address is already mapped to a worker id.
long oldWorkerId = existingWorker.getId();
LOG.warn("The worker {} already exists as id {}.", workerNetAddress, oldWorkerId);
return oldWorkerId;
}
MasterWorkerInfo lostWorker = mLostWorkers.getFirstByField(ADDRESS_INDEX, workerNetAddress);
if (lostWorker != null) {
// this is one of the lost workers
synchronized (lostWorker) {
final long lostWorkerId = lostWorker.getId();
LOG.warn("A lost worker {} has requested its old id {}.", workerNetAddress, lostWorkerId);
// Update the timestamp of the worker before it is considered an active worker.
lostWorker.updateLastUpdatedTimeMs();
mWorkers.add(lostWorker);
mLostWorkers.remove(lostWorker);
return lostWorkerId;
}
}
// Generate a new worker id.
long workerId = mNextWorkerId.getAndIncrement();
mWorkers.add(new MasterWorkerInfo(workerId, workerNetAddress));
LOG.info("getWorkerId(): WorkerNetAddress: {} id: {}", workerNetAddress, workerId);
return workerId;
}
/**
* Gets info about the lost workers.
*
* @return a set of worker info
*/
public Set<WorkerInfo> getLostWorkersInfo() {
Set<WorkerInfo> ret = new HashSet<>(mLostWorkers.size());
for (MasterWorkerInfo worker : mLostWorkers) {
synchronized (worker) {
ret.add(worker.generateClientWorkerInfo());
}
}
return ret;
}
/** @return the total used bytes on all tiers, on all workers of Alluxio */
public long getUsedBytes() {
long ret = 0;
for (MasterWorkerInfo worker : mWorkers) {
synchronized (worker) {
ret += worker.getUsedBytes();
}
}
return ret;
}
/** @return a list of {@link WorkerInfo} objects representing the workers in Alluxio */
public List<WorkerInfo> getWorkerInfoList() {
List<WorkerInfo> workerInfoList = new ArrayList<>(mWorkers.size());
for (MasterWorkerInfo worker : mWorkers) {
synchronized (worker) {
workerInfoList.add(worker.generateClientWorkerInfo());
}
}
return workerInfoList;
}
/** @return the used bytes on each storage tier */
public Map<String, Long> getUsedBytesOnTiers() {
Map<String, Long> ret = new HashMap<>();
for (MasterWorkerInfo worker : mWorkers) {
synchronized (worker) {
for (Map.Entry<String, Long> entry : worker.getUsedBytesOnTiers().entrySet()) {
Long used = ret.get(entry.getKey());
ret.put(entry.getKey(), (used == null ? 0L : used) + entry.getValue());
}
}
}
return ret;
}
@Override
public void heartbeat() {
int masterWorkerTimeoutMs = Configuration.getInt(Constants.MASTER_WORKER_TIMEOUT_MS);
for (MasterWorkerInfo worker : mWorkers) {
synchronized (worker) {
final long lastUpdate = CommonUtils.getCurrentMs() - worker.getLastUpdatedTimeMs();
if (lastUpdate > masterWorkerTimeoutMs) {
LOG.error(
"The worker {} timed out after {}ms without a heartbeat!", worker, lastUpdate);
mLostWorkers.add(worker);
mWorkers.remove(worker);
processWorkerRemovedBlocks(worker, worker.getBlocks());
}
}
}
}
/**
* Updates the worker and block metadata for blocks added to a worker.
*
* @param workerInfo The worker metadata object
* @param addedBlockIds A mapping from storage tier alias to a list of block ids added
*/
@GuardedBy("workerInfo")
private void processWorkerAddedBlocks(
MasterWorkerInfo workerInfo, Map<String, List<Long>> addedBlockIds) {
for (Map.Entry<String, List<Long>> entry : addedBlockIds.entrySet()) {
for (long blockId : entry.getValue()) {
MasterBlockInfo block = mBlocks.get(blockId);
if (block != null) {
synchronized (block) {
workerInfo.addBlock(blockId);
block.addWorker(workerInfo.getId(), entry.getKey());
mLostBlocks.remove(blockId);
}
} else {
LOG.warn("Failed to register workerId: {} to blockId: {}", workerInfo.getId(), blockId);
}
}
}
}
/**
* Removes blocks from workers.
*
* @param blockIds a list of block ids to remove from Alluxio space
* @param delete whether to delete blocks metadata in Master
*/
public void removeBlocks(List<Long> blockIds, boolean delete) {
for (long blockId : blockIds) {
MasterBlockInfo block = mBlocks.get(blockId);
if (block == null) {
continue;
}
HashSet<Long> workerIds = new HashSet<>();
synchronized (block) {
// Technically, 'block' should be confirmed to still be in the data structure. A
// concurrent removeBlock call can remove it. However, we are intentionally ignoring this
// race, since deleting the same block again is a noop.
workerIds.addAll(block.getWorkers());
// Two cases here:
// 1) For delete: delete the block metadata.
// 2) For free: keep the block metadata. mLostBlocks will be changed in
// processWorkerRemovedBlocks
if (delete) {
// Make sure blockId is removed from mLostBlocks when the block metadata is deleted.
// Otherwise blockId in mLostBlock can be dangling index if the metadata is gone.
mLostBlocks.remove(blockId);
mBlocks.remove(blockId);
}
}
// Outside of locking the block. This does not have to be synchronized with the block
// metadata, since it is essentially an asynchronous signal to the worker to remove the block.
for (long workerId : workerIds) {
MasterWorkerInfo worker = mWorkers.getFirstByField(ID_INDEX, workerId);
if (worker != null) {
synchronized (worker) {
worker.updateToRemovedBlock(true, blockId);
}
}
}
}
}
@Override
public Object getFieldValue(MasterWorkerInfo o) {
return o.getWorkerAddress();
}
// TODO(binfan): check the logic is correct or not when commitBlock is a retry
public void commitBlock(
long workerId, long usedBytesOnTier, String tierAlias, long blockId, long length)
throws NoWorkerException {
LOG.debug(
"Commit block from workerId: {}, usedBytesOnTier: {}, blockId: {}, length: {}",
workerId,
usedBytesOnTier,
blockId,
length);
long counter = AsyncJournalWriter.INVALID_FLUSH_COUNTER;
MasterWorkerInfo worker = mWorkers.getFirstByField(ID_INDEX, workerId);
// TODO(peis): Check lost workers as well.
if (worker == null) {
throw new NoWorkerException(ExceptionMessage.NO_WORKER_FOUND.getMessage(workerId));
}
// Lock the worker metadata first.
synchronized (worker) {
// Loop until block metadata is successfully locked.
for (; ; ) {
boolean newBlock = false;
MasterBlockInfo block = mBlocks.get(blockId);
if (block == null) {
// The block metadata doesn't exist yet.
block = new MasterBlockInfo(blockId, length);
newBlock = true;
}
// Lock the block metadata.
synchronized (block) {
boolean writeJournal = false;
if (newBlock) {
if (mBlocks.putIfAbsent(blockId, block) != null) {
// Another thread already inserted the metadata for this block, so start loop over.
continue;
}
// Successfully added the new block metadata. Append a journal entry for the new
// metadata.
writeJournal = true;
} else if (block.getLength() != length && block.getLength() == Constants.UNKNOWN_SIZE) {
// The block size was previously unknown. Update the block size with the committed
// size, and append a journal entry.
block.updateLength(length);
writeJournal = true;
}
if (writeJournal) {
BlockInfoEntry blockInfo =
BlockInfoEntry.newBuilder().setBlockId(blockId).setLength(length).build();
counter = appendJournalEntry(JournalEntry.newBuilder().setBlockInfo(blockInfo).build());
}
// At this point, both the worker and the block metadata are locked.
// Update the block metadata with the new worker location.
block.addWorker(workerId, tierAlias);
// This worker has this block, so it is no longer lost.
mLostBlocks.remove(blockId);
// Update the worker information for this new block.
// TODO(binfan): when retry commitBlock on master is expected, make sure metrics are not
// double counted.
worker.addBlock(blockId);
worker.updateUsedBytes(tierAlias, usedBytesOnTier);
worker.updateLastUpdatedTimeMs();
}
break;
}
}
waitForJournalFlush(counter);
}
