in src/java/org/apache/cassandra/db/Keyspace.java [445:597]
private Future<?> applyInternal(final Mutation mutation,
final boolean makeDurable,
boolean updateIndexes,
boolean isDroppable,
boolean isDeferrable,
Promise<?> future)
{
if (TEST_FAIL_WRITES && getMetadata().name.equals(TEST_FAIL_WRITES_KS))
throw new RuntimeException("Testing write failures");
Lock[] locks = null;
boolean requiresViewUpdate = updateIndexes && viewManager.updatesAffectView(mutation, false);
if (requiresViewUpdate)
{
Mutation.viewLockAcquireStartUpdater.compareAndSet(mutation, 0L, currentTimeMillis());
// the order of lock acquisition doesn't matter (from a deadlock perspective) because we only use tryLock()
Collection<TableId> tableIds = mutation.getTableIds();
Iterator<TableId> idIterator = tableIds.iterator();
locks = new Lock[tableIds.size()];
for (int i = 0; i < tableIds.size(); i++)
{
TableId tableId = idIterator.next();
int lockKey = Objects.hash(mutation.key().getKey(), tableId);
while (true)
{
Lock lock = null;
if (TEST_FAIL_MV_LOCKS_COUNT == 0)
lock = ViewManager.acquireLockFor(lockKey);
else
TEST_FAIL_MV_LOCKS_COUNT--;
if (lock == null)
{
//throw WTE only if request is droppable
if (isDroppable && (approxTime.isAfter(mutation.approxCreatedAtNanos + DatabaseDescriptor.getWriteRpcTimeout(NANOSECONDS))))
{
for (int j = 0; j < i; j++)
locks[j].unlock();
if (logger.isTraceEnabled())
logger.trace("Could not acquire lock for {} and table {}", ByteBufferUtil.bytesToHex(mutation.key().getKey()), columnFamilyStores.get(tableId).name);
Tracing.trace("Could not acquire MV lock");
if (future != null)
{
future.tryFailure(new WriteTimeoutException(WriteType.VIEW, ConsistencyLevel.LOCAL_ONE, 0, 1));
return future;
}
else
throw new WriteTimeoutException(WriteType.VIEW, ConsistencyLevel.LOCAL_ONE, 0, 1);
}
else if (isDeferrable)
{
for (int j = 0; j < i; j++)
locks[j].unlock();
// This view update can't happen right now. so rather than keep this thread busy
// we will re-apply ourself to the queue and try again later
Stage.MUTATION.execute(() ->
applyInternal(mutation, makeDurable, true, isDroppable, true, future)
);
return future;
}
else
{
// Retry lock on same thread, if mutation is not deferrable.
// Mutation is not deferrable, if applied from MutationStage and caller is waiting for future to finish
// If blocking caller defers future, this may lead to deadlock situation with all MutationStage workers
// being blocked by waiting for futures which will never be processed as all workers are blocked
try
{
// Wait a little bit before retrying to lock
Thread.sleep(10);
}
catch (InterruptedException e)
{
throw new UncheckedInterruptedException(e);
}
continue;
}
}
else
{
locks[i] = lock;
}
break;
}
}
long acquireTime = currentTimeMillis() - Mutation.viewLockAcquireStartUpdater.get(mutation);
// Metrics are only collected for droppable write operations
// Bulk non-droppable operations (e.g. commitlog replay, hint delivery) are not measured
if (isDroppable)
{
for(TableId tableId : tableIds)
columnFamilyStores.get(tableId).metric.viewLockAcquireTime.update(acquireTime, MILLISECONDS);
}
}
try (WriteContext ctx = getWriteHandler().beginWrite(mutation, makeDurable))
{
ConsensusMigrationMutationHelper.validateSafeToExecuteNonTransactionally(mutation);
for (PartitionUpdate upd : mutation.getPartitionUpdates())
{
ColumnFamilyStore cfs = columnFamilyStores.get(upd.metadata().id);
if (cfs == null)
{
logger.error("Attempting to mutate non-existant table {} ({}.{})", upd.metadata().id, upd.metadata().keyspace, upd.metadata().name);
continue;
}
AtomicLong baseComplete = null;
if (requiresViewUpdate)
{
baseComplete = new AtomicLong(Long.MAX_VALUE);
try
{
Tracing.trace("Creating materialized view mutations from base table replica");
viewManager.forTable(upd.metadata()).pushViewReplicaUpdates(upd, makeDurable, baseComplete);
}
catch (Throwable t)
{
JVMStabilityInspector.inspectThrowable(t);
logger.error(String.format("Unknown exception caught while attempting to update MaterializedView! %s",
upd.metadata().toString()), t);
throw t;
}
}
cfs.getWriteHandler().write(upd, ctx, updateIndexes);
if (requiresViewUpdate)
baseComplete.set(currentTimeMillis());
}
if (future != null) {
future.trySuccess(null);
}
return future;
}
finally
{
if (locks != null)
{
for (Lock lock : locks)
if (lock != null)
lock.unlock();
}
}
}