/**
Copyright (C) SYSTAP, LLC DBA Blazegraph 2006-2016. All rights reserved.
Contact:
SYSTAP, LLC DBA Blazegraph
2501 Calvert ST NW #106
Washington, DC 20008
licenses@blazegraph.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Created on Apr 22, 2007
*/
package com.bigdata.service.ndx;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.FutureTask;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import com.bigdata.btree.AsynchronousIndexWriteConfiguration;
import com.bigdata.btree.ICounter;
import com.bigdata.btree.IRangeQuery;
import com.bigdata.btree.ITuple;
import com.bigdata.btree.ITupleCursor;
import com.bigdata.btree.ITupleIterator;
import com.bigdata.btree.ITupleSerializer;
import com.bigdata.btree.IndexMetadata;
import com.bigdata.btree.ResultSet;
import com.bigdata.btree.keys.KVO;
import com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure.ResultBitBuffer;
import com.bigdata.btree.proc.AbstractKeyArrayIndexProcedure.ResultBuffer;
import com.bigdata.btree.proc.AbstractKeyArrayIndexProcedureConstructor;
import com.bigdata.btree.proc.AbstractKeyRangeIndexProcedure;
import com.bigdata.btree.proc.BatchContains.BatchContainsConstructor;
import com.bigdata.btree.proc.BatchInsert.BatchInsertConstructor;
import com.bigdata.btree.proc.BatchLookup.BatchLookupConstructor;
import com.bigdata.btree.proc.BatchPutIfAbsent.BatchPutIfAbsentConstructor;
import com.bigdata.btree.proc.BatchRemove.BatchRemoveConstructor;
import com.bigdata.btree.proc.IIndexProcedure;
import com.bigdata.btree.proc.IKeyArrayIndexProcedure;
import com.bigdata.btree.proc.IKeyRangeIndexProcedure;
import com.bigdata.btree.proc.IParallelizableIndexProcedure;
import com.bigdata.btree.proc.IResultHandler;
import com.bigdata.btree.proc.ISimpleIndexProcedure;
import com.bigdata.btree.proc.LongAggregator;
import com.bigdata.btree.proc.RangeCountProcedure;
import com.bigdata.counters.CounterSet;
import com.bigdata.journal.ITx;
import com.bigdata.journal.TimestampUtility;
import com.bigdata.mdi.IMetadataIndex;
import com.bigdata.mdi.IResourceMetadata;
import com.bigdata.mdi.MetadataIndex;
import com.bigdata.mdi.MetadataIndex.MetadataIndexMetadata;
import com.bigdata.mdi.PartitionLocator;
import com.bigdata.relation.accesspath.BlockingBuffer;
import com.bigdata.relation.accesspath.IRunnableBuffer;
import com.bigdata.relation.accesspath.UnsynchronizedArrayBuffer;
import com.bigdata.resources.StaleLocatorException;
import com.bigdata.service.AbstractClient;
import com.bigdata.service.AbstractScaleOutFederation;
import com.bigdata.service.IBigdataClient;
import com.bigdata.service.IBigdataClient.Options;
import com.bigdata.service.IBigdataFederation;
import com.bigdata.service.IDataService;
import com.bigdata.service.IMetadataService;
import com.bigdata.service.Split;
import com.bigdata.service.ndx.pipeline.IDuplicateRemover;
import com.bigdata.service.ndx.pipeline.IndexWriteTask;
import com.bigdata.util.InnerCause;
import com.bigdata.util.concurrent.ExecutionHelper;
import cutthecrap.utils.striterators.ICloseableIterator;
import cutthecrap.utils.striterators.IFilter;
/**
* <p>
* A client-side view of a scale-out index as of some <i>timestamp</i>.
* </p>
* <p>
* This view automatically handles the split, join, or move of index partitions
* within the federation. The {@link IDataService} throws back a (sometimes
* wrapped) {@link StaleLocatorException} when it does not have a registered
* index as of some timestamp. If this exception is observed when the client
* makes a request using a cached {@link PartitionLocator} record then the
* locator record is stale. The client automatically fetches the locator
* record(s) covering the same key range as the stale locator record and the
* re-issues the request against the index partitions identified in those
* locator record(s). This behavior correctly handles index partition split,
* merge, and move scenarios. The implementation of this policy is limited to
* exactly three places in the code: {@link AbstractDataServiceProcedureTask},
* {@link PartitionedTupleIterator}, and {@link DataServiceTupleIterator}.
* </p>
* <p>
* Note that only {@link ITx#UNISOLATED} and {@link ITx#READ_COMMITTED}
* operations are subject to stale locators since they are not based on a
* historical committed state of the database. Historical read and
* fully-isolated operations both read from historical committed states and the
* locators are never updated for historical states (only the current state of
* an index partition is split, joined, or moved - the historical states always
* remain behind).
* </p>
*
* @todo If the index was dropped then that should cause the operation to abort
* (only possible for read committed or unisolated operations).
* <p>
* Likewise, if a transaction is aborted, then then index should refuse
* further operations.
*
* @todo detect data service failure and coordinate cutover to the failover data
* services. ideally you can read on a failover data service at any time
* but it should not accept write operations unless it is the primary data
* service in the failover chain.
* <p>
* Offer policies for handling index partitions that are unavailable at
* the time of the request (continued operation during partial failure).
*
* @todo We should be able to transparently use either a hash mod N approach to
* distributed index partitions or a dynamic approach based on overflow.
* This could even be decided on a per-index basis. The different
* approaches would be hidden by appropriate implementations of this
* class.
* <p>
* A hash partitioned index will need to enforce optional read-consistent
* semantics. This can be done by choosing a recent broadcast commitTime
* for the read or by re-issuing queries that come in with a different
* commitTime.
*
@todo This class could consolidate parallelized operations by data service,
* issuing a chunk of requests for each index partition on a given data
* service. This would reduce the #of RMI requests to one per data service
* against which the parallelized operation must be mapped.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan Thompson</a>
*/
public class ClientIndexView implements IScaleOutClientIndex {
/**
* Note: Invocations of the non-batch API are logged at the WARN level since
* they result in an application that can not scale-out efficiently.
*/
protected static final transient Logger log = Logger
.getLogger(ClientIndexView.class);
/**
* True iff the {@link #log} level is WARN or less.
*/
final protected boolean WARN = log.getEffectiveLevel().toInt() <= Level.WARN
.toInt();
/**
* Error message used if we were unable to start a new transaction in order
* to provide read-consistent semantics for an {@link ITx#READ_COMMITTED}
* view or for a read-only operation on an {@link ITx#UNISOLATED} view.
*/
static protected final transient String ERR_NEW_TX = "Could not start transaction";
/**
* Error message used if we were unable to abort a transaction that we
* started in order to provide read-consistent semantics for an
* {@link ITx#READ_COMMITTED} view or for a read-only operation on an
* {@link ITx#UNISOLATED} view.
*/
static protected final transient String ERR_ABORT_TX = "Could not abort transaction: tx=";
private final AbstractScaleOutFederation<?> fed;
public AbstractScaleOutFederation<?> getFederation() {
return fed;
}
/**
* The thread pool exposed by {@link IBigdataFederation#getExecutorService()}
*/
protected ThreadPoolExecutor getThreadPool() {
return (ThreadPoolExecutor) fed.getExecutorService();
}
/**
* The timeout in milliseconds for tasks run on an {@link IDataService}.
*
* @see Options#CLIENT_TASK_TIMEOUT
*/
private final long taskTimeout;
/**
*
*/
protected static final String NON_BATCH_API = "Non-batch API";
/**
* This may be used to disable the non-batch API, which is quite convenient
* for locating code that needs to be re-written to use
* {@link IIndexProcedure}s.
*/
private final boolean batchOnly;
/**
* The default capacity for the {@link #rangeIterator(byte[], byte[])}
*/
private final int capacity;
/**
* The timestamp from the ctor.
*/
private final long timestamp;
final public long getTimestamp() {
return timestamp;
}
/**
* The name of the scale-out index (from the ctor).
*/
private final String name;
final public String getName() {
return name;
}
/**
* The {@link IMetadataIndex} for this scale-out index.
*
* @todo This is a bit dangerous since most of the time when you want the
* metadata index you may have a timestamp in effect which is
* different from the timestamp of the view (e.g., a read-consistent
* transaction).
*/
private final IMetadataIndex metadataIndex;
/**
* The {@link IndexMetadata} for the {@link MetadataIndex} that manages the
* scale-out index. The metadata template for the managed scale-out index is
* available as a field on this object.
*/
private final MetadataIndexMetadata metadataIndexMetadata;
/**
* Obtain the proxy for a metadata service. if this instance fails, then we
* can always ask for a new instance for the same federation (failover).
*/
final protected IMetadataService getMetadataService() {
return fed.getMetadataService();
}
/**
* Knows how to break down key[][]s into {@link Split}s.
*/
private final ISplitter splitter;
/**
* Return a view of the metadata index for the scale-out index as of the
* timestamp associated with this index view.
*
* @todo This is a bit dangerous since most of the time when you want the
* metadata index you may have a timestamp in effect which is
* different from the timestamp of the view (e.g., a read-consistent
* transaction).
*
* @todo should be protected, but some unit tests in a different package
* access this.
*
* @see IBigdataFederation#getMetadataIndex(String, long)
*/
final public IMetadataIndex getMetadataIndex() {
return metadataIndex;
}
/**
*
* @see #getRecursionDepth()
*/
private ThreadLocal<AtomicInteger> recursionDepth = new ThreadLocal<AtomicInteger>() {
protected synchronized AtomicInteger initialValue() {
return new AtomicInteger();
}
};
public AtomicInteger getRecursionDepth() {
return recursionDepth.get();
}
/**
* @see IBigdataClient#isReadConsistent()
*/
final private boolean readConsistent;
public String toString() {
final StringBuilder sb = new StringBuilder();
sb.append(getClass().getSimpleName());
sb.append("{ ");
sb.append("name=" + name);
sb.append(", timestamp=" + timestamp);
sb.append(", readConsistent=" + readConsistent);
sb.append("}");
return sb.toString();
}
/**
* Create a view on a scale-out index.
*
* @param fed
* The federation containing the index.
* @param name
* The index name.
* @param timestamp
* A transaction identifier, {@link ITx#UNISOLATED} for the
* unisolated index view, {@link ITx#READ_COMMITTED}, or
* <code>timestamp</code> for a historical view no later than
* the specified timestamp.
* @param metadataIndex
* The {@link IMetadataIndex} for the named scale-out index as of
* that timestamp. Note that the {@link IndexMetadata} on this
* object contains the template {@link IndexMetadata} for the
* scale-out index partitions.
*/
public ClientIndexView(final AbstractScaleOutFederation<?> fed,
final String name, final long timestamp,
final IMetadataIndex metadataIndex) {
if (fed == null)
throw new IllegalArgumentException();
if (name == null)
throw new IllegalArgumentException();
if (metadataIndex == null)
throw new IllegalArgumentException();
this.fed = fed;
this.name = name;
this.timestamp = timestamp;
this.metadataIndex = metadataIndex;
this.metadataIndexMetadata = metadataIndex.getIndexMetadata();
this.splitter = new AbstractSplitter() {
@Override
protected IMetadataIndex getMetadataIndex(final long ts) {
return fed.getMetadataIndex(name, ts);
}
};
final AbstractClient<?> client = fed.getClient();
this.capacity = client.getDefaultRangeQueryCapacity();
this.batchOnly = client.getBatchApiOnly();
this.taskTimeout = client.getTaskTimeout();
this.readConsistent = client.isReadConsistent();
}
/**
* Metadata for the {@link MetadataIndex} that manages the scale-out index
* (cached).
*/
public MetadataIndexMetadata getMetadataIndexMetadata() {
return metadataIndexMetadata;
}
/**
* The metadata for the managed scale-out index. Among other things, this
* gets used to determine how we serialize keys and values for
* {@link IKeyArrayIndexProcedure}s when we serialize a procedure to be
* sent to a remote {@link IDataService}.
*/
public IndexMetadata getIndexMetadata() {
return metadataIndexMetadata.getManagedIndexMetadata();
}
public ICounter getCounter() {
throw new UnsupportedOperationException();
}
private volatile ITupleSerializer tupleSer = null;
protected ITupleSerializer getTupleSerializer() {
if (tupleSer == null) {
synchronized (this) {
if (tupleSer == null) {
tupleSer = getIndexMetadata().getTupleSerializer();
}
}
}
return tupleSer;
}
@Override
public boolean contains(Object key) {
key = getTupleSerializer().serializeKey(key);
return contains((byte[])key);
}
@Override
public boolean contains(final byte[] key) {
if (batchOnly)
log.error(NON_BATCH_API,new RuntimeException());
else
if(WARN) log.warn(NON_BATCH_API);
final byte[][] keys = new byte[][] { key };
final IResultHandler resultHandler = new IdentityHandler();
submit(0/* fromIndex */, 1/* toIndex */, keys, null/* vals */,
BatchContainsConstructor.INSTANCE, resultHandler);
return ((ResultBitBuffer) resultHandler.getResult()).getResult()[0];
}
@Override
public Object insert(Object key,Object val) {
final ITupleSerializer tupleSer = getTupleSerializer();
key = tupleSer.serializeKey(key);
val = tupleSer.serializeKey(val);
final byte[] oldval = insert((byte[])key, (byte[])val);
// FIXME decode tuple to old value.
throw new UnsupportedOperationException();
}
@Override
public byte[] insert(final byte[] key, final byte[] value) {
if (batchOnly)
log.error(NON_BATCH_API,new RuntimeException());
else
if(WARN) log.warn(NON_BATCH_API);
final byte[][] keys = new byte[][] { key };
final byte[][] vals = new byte[][] { value };
final IResultHandler resultHandler = new IdentityHandler();
submit(0/* fromIndex */, 1/* toIndex */, keys, vals,
BatchInsertConstructor.RETURN_OLD_VALUES, resultHandler);
return ((ResultBuffer) resultHandler.getResult()).getResult(0);
}
@Override
public byte[] putIfAbsent(final byte[] key, final byte[] value) {
if (batchOnly)
log.error(NON_BATCH_API,new RuntimeException());
else
if(WARN) log.warn(NON_BATCH_API);
final byte[][] keys = new byte[][] { key };
final byte[][] vals = new byte[][] { value };
final IResultHandler resultHandler = new IdentityHandler();
submit(0/* fromIndex */, 1/* toIndex */, keys, vals,
BatchPutIfAbsentConstructor.RETURN_OLD_VALUES, resultHandler);
return ((ResultBuffer) resultHandler.getResult()).getResult(0);
}
@Override
public Object lookup(Object key) {
key = getTupleSerializer().serializeKey(key);
final byte[] val = lookup((byte[])key);
// FIXME decode tuple to old value.
throw new UnsupportedOperationException();
}
@Override
public byte[] lookup(final byte[] key) {
if (batchOnly)
log.error(NON_BATCH_API,new RuntimeException());
else
if(WARN) log.warn(NON_BATCH_API);
final byte[][] keys = new byte[][]{key};
final IResultHandler resultHandler = new IdentityHandler();
submit(0/* fromIndex */, 1/* toIndex */, keys, null/* vals */,
BatchLookupConstructor.INSTANCE, resultHandler);
return ((ResultBuffer) resultHandler.getResult()).getResult(0);
}
@Override
public Object remove(Object key) {
key = getTupleSerializer().serializeKey(key);
final byte[] oldval = remove((byte[])key);
// FIXME decode tuple to old value.
throw new UnsupportedOperationException();
}
@Override
public byte[] remove(final byte[] key) {
if (batchOnly)
log.error(NON_BATCH_API,new RuntimeException());
else
if(WARN) log.warn(NON_BATCH_API);
final byte[][] keys = new byte[][]{key};
final IResultHandler resultHandler = new IdentityHandler();
submit(0/* fromIndex */, 1/* toIndex */, keys, null/* vals */,
BatchRemoveConstructor.RETURN_OLD_VALUES, resultHandler);
return ((ResultBuffer) resultHandler.getResult()).getValues().get(0);
}
/*
* All of these methods need to divide up the operation across index
* partitions.
*/
@Override
public long rangeCount() {
return rangeCount(null, null);
}
/**
* Returns the sum of the range count for each index partition spanned by
* the key range.
*
* @see <a href="http://sourceforge.net/apps/trac/bigdata/ticket/470">
* Optimize range counts on cluster </a>
*/
@Override
public long rangeCount(final byte[] fromKey, final byte[] toKey) {
final LongAggregator handler = new LongAggregator();
final RangeCountProcedure proc = new RangeCountProcedure(
false/* exact */, false/* deleted */, fromKey, toKey);
submit(fromKey, toKey, proc, handler);
return handler.getResult();
}
/**
* The exact range count is obtained by mapping a key-range scan over the
* index partitions. The operation is parallelized.
*/
@Override
final public long rangeCountExact(final byte[] fromKey, final byte[] toKey) {
final LongAggregator handler = new LongAggregator();
final RangeCountProcedure proc = new RangeCountProcedure(
true/* exact */, false/*deleted*/, fromKey, toKey);
submit(fromKey, toKey, proc, handler);
return handler.getResult();
}
/**
* The exact range count of deleted and undeleted tuples is obtained by
* mapping a key-range scan over the index partitions. The operation is
* parallelized.
*/
@Override
final public long rangeCountExactWithDeleted(final byte[] fromKey,
final byte[] toKey) {
final LongAggregator handler = new LongAggregator();
final RangeCountProcedure proc = new RangeCountProcedure(
true/* exact */, true/* deleted */, fromKey, toKey);
submit(fromKey, toKey, proc, handler);
return handler.getResult();
}
@Override
final public ITupleIterator rangeIterator() {
return rangeIterator(null, null);
}
/**
* An {@link ITupleIterator} that kinds the use of a series of
* {@link ResultSet}s to cover all index partitions spanned by the key
* range.
*/
@Override
public ITupleIterator rangeIterator(final byte[] fromKey, final byte[] toKey) {
return rangeIterator(fromKey, toKey, capacity,
IRangeQuery.DEFAULT /* flags */, null/* filter */);
}
/**
* Identifies the index partition(s) that are spanned by the key range query
* and maps an iterator across each index partition. The iterator buffers
* responses up to the specified capacity and a follow up iterator request
* is automatically issued if the iterator has not exhausted the key range
* on a given index partition. Once the iterator is exhausted on a given
* index partition it is then applied to the next index partition spanned by
* the key range.
*
* @todo If the return iterator implements {@link ITupleCursor} then this
* will need be modified to defer request of the initial result set
* until the caller uses first(), last(), seek(), hasNext(), or
* hasPrior().
*/
@Override
public ITupleIterator rangeIterator(final byte[] fromKey,
final byte[] toKey, int capacity, final int flags,
final IFilter filter) {
if (capacity == 0) {
capacity = this.capacity;
}
// Parallel scan of each index partition?
final boolean parallel = ((flags & PARALLEL) != 0);
/*
* Does the iterator declare that it will not write back on the index?
*/
final boolean readOnly = ((flags & READONLY) != 0);
if (readOnly && ((flags & REMOVEALL) != 0)) {
throw new IllegalArgumentException();
}
final boolean isReadConsistentTx;
final long ts;
if ((timestamp == ITx.UNISOLATED && readOnly)
|| (timestamp == ITx.READ_COMMITTED && readConsistent)) {
try {
// run as globally consistent read.
ts = fed.getTransactionService().newTx(ITx.READ_COMMITTED);
} catch (IOException ex) {
throw new RuntimeException(ERR_NEW_TX, ex);
}
isReadConsistentTx = true;
} else {
ts = timestamp;
isReadConsistentTx = false;
}
try {
if (parallel) {
/*
* Parallel iterator scan. This breaks the total ordering
* guarantee of the iterator in exchange for faster visitation
* of the tuples in key range which spans multiple index
* partitions.
*/
return parallelRangeIterator(ts, isReadConsistentTx, fromKey,
toKey, capacity, flags, filter);
} else {
/*
* Process the index partitions in key order so the total order
* of the keys is preserved by the iterator visitation ordering.
*/
return new PartitionedTupleIterator(this, ts,
isReadConsistentTx, fromKey, toKey, capacity, flags,
filter);
}
} catch (Throwable t) {
if (isReadConsistentTx) {
/*
* Terminate the transaction since we created it ourselves.
*/
try {
fed.getTransactionService().abort(ts);
} catch (Throwable t2) {
log.error(t2, t2);
}
}
throw new RuntimeException(t);
}
}
/**
* Parallel iterator scan. This breaks the total ordering guarantee of the
* iterator in exchange for faster visitation of the tuples in key range
* which spans multiple index partitions.
*
* @param ts
* The timestamp for the view (may be a transaction).
* @param isReadConsistentTx
* <code>true</code> iff the caller specified timestamp is a
* read-historical transaction created specifically to give the
* iterator read-consistent semantics. when <code>true</code>,
* this class will ensure that the transaction is eventually
* aborted so that its read lock will be released. This is done
* eagerly when the iterator is exhausted and with a
* {@link #finalize()} method otherwise.
* @param fromKey
* @param toKey
* @param capacity
* @param flags
* @param filter
* @return
*/
private ITupleIterator parallelRangeIterator(final long ts,
final boolean isReadConsistentTx, final byte[] fromKey,
final byte[] toKey, final int capacity, final int flags,
final IFilter filter) {
/*
* Set up the buffer for aggregating the results from the range
* iterators over each index partition.
*
* Note: The range iterators will themselves be chunked, so the chunk
* size and chunk timeout should not matter too much. As long as they
* are small, chunks should be made visible via the asynchronous
* iterator as soon as they are received from the remote data service.
*/
final int minimumChunkSize = 100;
final long chunkTimeout = 1;
final TimeUnit chunkTimeoutUnit = TimeUnit.MILLISECONDS;
final BlockingBuffer<ITuple<?>[]> queryBuffer = new BlockingBuffer<ITuple<?>[]>(
capacity, minimumChunkSize, chunkTimeout, chunkTimeoutUnit);
/*
* This task will map the range iterator over the index partitions with
* limited parallelism.
*/
final ParallelRangeIteratorTask task = new ParallelRangeIteratorTask(
ts, isReadConsistentTx, fromKey, toKey, capacity, flags,
filter, queryBuffer);
/**
* @see <a href="https://sourceforge.net/apps/trac/bigdata/ticket/707">
* BlockingBuffer.close() does not unblock threads </a>
*/
// Wrap computation as FutureTask.
final FutureTask<Void> ft = new FutureTask<Void>(task);
// Set Future on BlockingBuffer.
queryBuffer.setFuture(ft);
// Submit computation for evaluation.
fed.getExecutorService().submit(ft);
return new UnchunkedTupleIterator(queryBuffer.iterator());
}
/**
* Converts a chunked iterator to an {@link ITupleIterator}.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan
* Thompson</a>
* @param <E>
*/
private static class UnchunkedTupleIterator<E> implements ITupleIterator<E> {
private final ICloseableIterator<ITuple<E>[]> src;
private ITuple<E>[] chunk = null;
private int index = 0;
private boolean exhausted = false;
public UnchunkedTupleIterator(final ICloseableIterator<ITuple<E>[]> src) {
if (src == null)
throw new IllegalArgumentException();
this.src = src;
}
//@Override
@Override
public boolean hasNext() {
while (!exhausted
&& (chunk == null || chunk.length == 0 || index >= chunk.length)) {
// refresh with another chunk from the source.
if (!src.hasNext()) {
exhausted = true;
break;
}
chunk = src.next();
index = 0;
}
return !exhausted;
}
@Override
public ITuple<E> next() {
if (!hasNext())
throw new NoSuchElementException();
return chunk[index++];
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
/**
* @todo {@link ITupleIterator} should extend {@link ICloseableIterator}
* so we do not need to do this in a finalizer. A finalizer is
* driven by GC on the client, but the iterator could be doing a
* lot of work on the remote data services in which case the
* client GC might not be timely.
*/
@Override
protected void finalize() throws Exception {
src.close();
}
}
/**
* Inner class runs a range iterator mapped in parallel across multiple
* index partitions.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan
* Thompson</a>
* @version $Id$
*
* @todo report counters for iterator operations.
*/
private class ParallelRangeIteratorTask implements Callable<Void> {
final private long ts;
final private boolean isReadConsistentTx;
final private byte[] fromKey;
final private byte[] toKey;
final private int capacity;
final private int flags;
final private IFilter filter;
final private BlockingBuffer<ITuple<?>[]> queryBuffer;
/** The maximum #of tasks to queue at once. */
final private int maxTasks;
final private ExecutionHelper<Void> helper;
public ParallelRangeIteratorTask(final long ts,
final boolean isReadConsistentTx, final byte[] fromKey,
final byte[] toKey, final int capacity, final int flags,
final IFilter filter,
final BlockingBuffer<ITuple<?>[]> queryBuffer) {
this.ts = ts;
this.isReadConsistentTx = isReadConsistentTx;
this.fromKey = fromKey;
this.toKey = toKey;
this.capacity = capacity;
this.flags = flags;
this.filter = filter;
this.queryBuffer = queryBuffer;
final int poolSize = ((ThreadPoolExecutor) getThreadPool())
.getCorePoolSize();
final int maxTasksPerRequest = fed.getClient()
.getMaxParallelTasksPerRequest();
// max #of tasks to queue at once.
maxTasks = poolSize == 0 ? maxTasksPerRequest : Math.min(
poolSize, maxTasksPerRequest);
// verify positive or the loop below will fail to progress.
assert maxTasks > 0 : "maxTasks=" + maxTasks + ", poolSize="
+ poolSize + ", maxTasksPerRequest=" + maxTasksPerRequest;
helper = new ExecutionHelper<Void>(fed.getExecutorService(), fed
.getClient().getTaskTimeout(), TimeUnit.MILLISECONDS);
}
@Override
public Void call() throws Exception {
try {
/*
* Scan visits index partition locators in key order.
*
* Note: We are using the caller's timestamp.
*
* Note: This iterator is not "closable".
*/
final Iterator<PartitionLocator> itr = locatorScan(ts, fromKey,
toKey, false/* reverseScan */);
long nparts = 0;
while (itr.hasNext()) {
/*
* Process the remaining locators a "chunk" at a time. The
* chunk size is chosen to be the configured size of the
* client thread pool. This lets us avoid overwhelming the
* thread pool queue when mapping a procedure across a very
* large #of index partitions.
*
* The result is an ordered list of the tasks to be
* executed. The order of the tasks is determined by the
* natural order of the index partitions - that is, we
* submit the tasks in key order so that a
* non-parallelizable procedure will be mapped in the
* correct sequence.
*/
final ArrayList<Callable<Void>> tasks = new ArrayList<Callable<Void>>(
maxTasks);
for (int i = 0; i < maxTasks && itr.hasNext(); i++) {
final PartitionLocator locator = itr.next();
/*
* Constrain the iterator's range to the intersection of
* the index partition and the original iterator range.
*/
final byte[] _fromKey = AbstractKeyRangeIndexProcedure
.constrainFromKey(fromKey, locator);
final byte[] _toKey = AbstractKeyRangeIndexProcedure
.constrainToKey(toKey, locator);
tasks.add(new RobustIteratorTask(_fromKey, _toKey));
nparts++;
}
helper.submitTasks(tasks);
} // next (chunk of) locators.
// Done.
return null;
} catch (Throwable t) {
if (isReadConsistentTx) {
fed.getTransactionService().abort(ts);
}
throw new RuntimeException(t);
}
}
/**
* Runs an iterator against a key-range. If an index partition is split,
* joined or moved then the iterator will follow the data. If the
* {@link BlockingBuffer} is closed, then this task will terminate.
*
* @author <a href="mailto:thompsonbry@users.sourceforge.net">Bryan
* Thompson</a>
* @version $Id$
*/
private class RobustIteratorTask implements Callable<Void> {
private final PartitionedTupleIterator itr;
/**
*
* @param fromKey
* @param toKey
*/
RobustIteratorTask(final byte[] fromKey, final byte[] toKey) {
itr = new PartitionedTupleIterator(ClientIndexView.this, ts,
isReadConsistentTx, fromKey, toKey, capacity, flags,
filter);
}
@Override
public Void call() throws Exception {
try {
final UnsynchronizedArrayBuffer unsyncBuffer = new UnsynchronizedArrayBuffer(
queryBuffer, ITuple.class, queryBuffer.getMinimumChunkSize());
while (itr.hasNext()) {
if (!queryBuffer.isOpen()) {
// Terminate early.
break;
}
unsyncBuffer.add(itr.next());
}
if (queryBuffer.isOpen()) {
// flush buffer if the target buffer is still open.
unsyncBuffer.flush();
}
} catch (Throwable t) {
if (InnerCause.isInnerCause(t, InterruptedException.class)) {
queryBuffer.abort(t);
}
throw new RuntimeException(t);
}
// done.
return null;
}
} // RobustIteratorTask
}
/**
* {@inheritDoc}
* <p>
* Note: Because the procedure is submitted against a single key, it is
* assumed to address a single shard. Therefore, a read-consistent view of
* the index will NOT be obtained for read-committed or unisolated requests
* as the operation should already be shard-wise ACID and it addresses only
* a single shard. This effects all read-only point operations on the index,
* including lookup() and contains() as well as custom procedures such as
* GRS reads.
* <p>
* Procedures which require read-consistent protection across more than one
* shard MUST be designed with a <i>fromKey</i> and a <i>toKey</i> rather
* than just a <i>key</i>. The <i>fromKey</i> and <i>toKey</i> are used to
* identify the relevant shard(s) spanned by the operation. Read-consistent
* isolation is then optionally imposed depending on the client.
*
* @see <a href="https://sourceforge.net/apps/trac/bigdata/ticket/454">
* Global Row Store Read on Cluster uses Tx </a>
*/
@Override
public <T> T submit(final byte[] key, final ISimpleIndexProcedure<T> proc) {
if (false && readConsistent && proc.isReadOnly()
&& TimestampUtility.isReadCommittedOrUnisolated(getTimestamp())) {
/*
* Use globally consistent reads for the mapped procedure.
*/
final long tx;
try {
tx = fed.getTransactionService().newTx(ITx.READ_COMMITTED);
} catch (IOException ex) {
throw new RuntimeException(ERR_NEW_TX, ex);
}
try {
return submit(tx, key, proc);
} finally {
try {
fed.getTransactionService().abort(tx);
} catch (IOException ex) {
// log error and ignore since the operation is complete.
log.error(ERR_ABORT_TX + tx, ex);
}
}
} else {
/*
* Timestamp is either a tx already or the caller is risking errors
* with lightweight historical reads.
*/
return submit(timestamp, key, proc);
}
}
/**
* Variant uses the caller's timestamp.
*
* @param ts
* @param key
* @param proc
* @return
*/
private <T> T submit(final long ts, final byte[] key,
final ISimpleIndexProcedure<T> proc) {
// Find the index partition spanning that key.
final PartitionLocator locator = fed.getMetadataIndex(name, ts).find(
key);
/*
* Submit procedure to that data service.
*/
try {
if (log.isInfoEnabled()) {
log.info("Submitting " + proc.getClass() + " to partition"
+ locator);
}
// required to get the result back from the procedure.
final IResultHandler<T, T> resultHandler = new IdentityHandler<T>();
final SimpleDataServiceProcedureTask task = new SimpleDataServiceProcedureTask(
this, key, ts, new Split(locator, 0, 0), proc, resultHandler);
// submit procedure and await completion.
getThreadPool().submit(task).get(taskTimeout, TimeUnit.MILLISECONDS);
// the singleton result.
final T result = resultHandler.getResult();
return result;
} catch (Exception ex) {
throw new RuntimeException(ex);
}
}
@Override
@SuppressWarnings("unchecked")
public Iterator<PartitionLocator> locatorScan(final long ts,
final byte[] fromKey, final byte[] toKey, final boolean reverseScan) {
return fed.locatorScan(name, ts, fromKey, toKey, reverseScan);
}
/**
* Maps an {@link IIndexProcedure} across a key range by breaking it down
* into one task per index partition spanned by that key range.
* <p>
* Note: In order to avoid growing the task execution queue without bound,
* an upper bound of {@link Options#CLIENT_MAX_PARALLEL_TASKS_PER_REQUEST}
* tasks will be placed onto the queue at a time. More tasks will be
* submitted once those tasks finish until all tasks have been executed.
* When the task is not parallelizable the tasks will be submitted to the
* corresponding index partitions at a time and in key order.
*/
@Override
public void submit(final byte[] fromKey, final byte[] toKey,
final IKeyRangeIndexProcedure proc, final IResultHandler resultHandler) {
if (proc == null)
throw new IllegalArgumentException();
if (readConsistent && proc.isReadOnly()
&& TimestampUtility.isReadCommittedOrUnisolated(getTimestamp())) {
/*
* Use globally consistent reads for the mapped procedure.
*/
final long tx;
try {
tx = fed.getTransactionService().newTx(ITx.READ_COMMITTED);
} catch (IOException ex) {
throw new RuntimeException(ERR_NEW_TX, ex);
}
try {
submit(tx, fromKey, toKey, proc, resultHandler);
} finally {
try {
fed.getTransactionService().abort(tx);
} catch (IOException ex) {
// log error and ignore since the operation is complete.
log.error(ERR_ABORT_TX + tx, ex);
}
}
} else {
/*
* Timestamp is either a tx already or the caller is risking errors
* with lightweight historical reads.
*/
submit(timestamp, fromKey, toKey, proc, resultHandler);
}
}
/**
* Variant uses the caller's timestamp.
*
* @param ts
* @param fromKey
* @param toKey
* @param proc
* @param resultHandler
*/
void submit(final long ts, final byte[] fromKey,
final byte[] toKey, final IKeyRangeIndexProcedure proc,
final IResultHandler resultHandler) {
// true iff the procedure is known to be parallelizable.
final boolean parallel = proc instanceof IParallelizableIndexProcedure;
if (log.isInfoEnabled())
log.info("Procedure " + proc.getClass().getName()
+ " will be mapped across index partitions in "
+ (parallel ? "parallel" : "sequence"));
final int poolSize = ((ThreadPoolExecutor) getThreadPool())
.getCorePoolSize();
final int maxTasksPerRequest = fed.getClient()
.getMaxParallelTasksPerRequest();
// max #of tasks to queue at once.
final int maxTasks = poolSize == 0 ? maxTasksPerRequest : Math.min(
poolSize, maxTasksPerRequest);
// verify positive or the loop below will fail to progress.
assert maxTasks > 0 : "maxTasks=" + maxTasks + ", poolSize=" + poolSize
+ ", maxTasksPerRequest=" + maxTasksPerRequest;
/*
* Scan visits index partition locators in key order.
*
* Note: We are using the caller's timestamp.
*/
final Iterator<PartitionLocator> itr = locatorScan(ts, fromKey, toKey,
false/* reverseScan */);
long nparts = 0;
while (itr.hasNext()) {
/*
* Process the remaining locators a "chunk" at a time. The chunk
* size is chosen to be the configured size of the client thread
* pool. This lets us avoid overwhelming the thread pool queue when
* mapping a procedure across a very large #of index partitions.
*
* The result is an ordered list of the tasks to be executed. The
* order of the tasks is determined by the natural order of the
* index partitions - that is, we submit the tasks in key order so
* that a non-parallelizable procedure will be mapped in the correct
* sequence.
*/
final ArrayList<AbstractDataServiceProcedureTask> tasks = new ArrayList<AbstractDataServiceProcedureTask>(
maxTasks);
for (int i = 0; i < maxTasks && itr.hasNext(); i++) {
final PartitionLocator locator = itr.next();
final Split split = new Split(locator, 0/* fromIndex */, 0/* toIndex */);
// Note: task will constrain fromKey/toKey to partition.
tasks.add(new KeyRangeDataServiceProcedureTask(this, fromKey, toKey,
ts, split, proc, resultHandler));
nparts++;
}
runTasks(parallel, tasks);
} // next (chunk of) locators.
if (log.isInfoEnabled())
log.info("Procedure " + proc.getClass().getName()
+ " mapped across " + nparts + " index partitions in "
+ (parallel ? "parallel" : "sequence"));
}
/**
* The procedure will be transparently broken down and executed against each
* index partitions spanned by its keys. If the <i>ctor</i> creates
* instances of {@link IParallelizableIndexProcedure} then the procedure
* will be mapped in parallel against the relevant index partitions.
* <p>
* Note: Unlike mapping an index procedure across a key range, this method
* is unable to introduce a truly enormous burden on the client's task
* queue since the #of tasks arising is equal to the #of splits and bounded
* by <code>n := toIndex - fromIndex</code>.
*
* @return The aggregated result of applying the procedure to the relevant
* index partitions.
*/
@Override
public void submit(final int fromIndex, final int toIndex,
final byte[][] keys, final byte[][] vals,
final AbstractKeyArrayIndexProcedureConstructor ctor,
final IResultHandler aggregator) {
if (ctor == null) {
throw new IllegalArgumentException();
}
// iff we created a read-historical tx in this method.
final boolean isTx;
// the timestamp that will be used for the operation.
final long ts;
{
/*
* Instantiate the procedure on all the data so we can figure out if
* it is read-only and whether or not we need to create a read-only
* transaction to run it.
*
* FIXME This assumes that people write procedures that are fly
* weight in how they encode the data in their ctor. If they don't
* then there could be a LOT overhead for this. For example, this
* can cause a problem if we are using the same RabaCoders that are
* used for the leaves in the index since the compression technique
* will be applied to all of the data in this step.
*/
final IKeyArrayIndexProcedure proc = ctor.newInstance(this,
fromIndex, toIndex, keys, vals);
if (readConsistent
&& proc.isReadOnly()
&& TimestampUtility
.isReadCommittedOrUnisolated(getTimestamp())) {
/*
* Create a read-historical transaction from the last commit
* point of the federation in order to provide consistent
* reads for the mapped procedure.
*/
isTx = true;
try {
ts = fed.getTransactionService().newTx(ITx.READ_COMMITTED);
} catch (IOException e) {
throw new RuntimeException(ERR_NEW_TX, e);
}
} else {
// might be a tx, but not one that we created here.
isTx = false;
ts = getTimestamp();
}
}
try {
submit(ts, fromIndex, toIndex, keys, vals, ctor, aggregator);
} finally {
if (isTx) {
try {
fed.getTransactionService().abort(ts);
} catch (IOException e) {
/*
* log error but do not rethrow since operation is over
* anyway.
*/
log.error(ERR_ABORT_TX + ": " + ts, e);
}
}
}
}
/**
* Variant uses the caller's timestamp.
*
* @param ts
* @param fromIndex
* @param toIndex
* @param keys
* @param vals
* @param ctor
* @param aggregator
*/
void submit(final long ts, final int fromIndex, final int toIndex,
final byte[][] keys, final byte[][] vals,
final AbstractKeyArrayIndexProcedureConstructor ctor,
final IResultHandler aggregator) {
/*
* Break down the data into a series of "splits", each of which will be
* applied to a different index partition.
*
* Note: We are using the caller's timestamp here so this will have
* read-consistent semantics!
*/
final LinkedList<Split> splits = splitKeys(ts, fromIndex, toIndex, keys);
final int nsplits = splits.size();
/*
* Create the instances of the procedure for each split.
*/
final ArrayList<AbstractDataServiceProcedureTask> tasks = new ArrayList<AbstractDataServiceProcedureTask>(
nsplits);
final Iterator<Split> itr = splits.iterator();
boolean parallel = false;
while (itr.hasNext()) {
final Split split = itr.next();
final IKeyArrayIndexProcedure proc = ctor.newInstance(this,
split.fromIndex, split.toIndex, keys, vals);
if (proc instanceof IParallelizableIndexProcedure) {
parallel = true;
}
tasks.add(new KeyArrayDataServiceProcedureTask(this, keys, vals, ts,
split, proc, aggregator, ctor));
}
if (log.isInfoEnabled())
log.info("Procedures created by " + ctor.getClass().getName()
+ " will run on " + nsplits + " index partitions in "
+ (parallel ? "parallel" : "sequence"));
runTasks(parallel, tasks);
}
/**
* Runs a set of tasks.
* <p>
* Note: If {@link #getRecursionDepth()} evaluates to a value larger than
* zero then the task(s) will be forced to execute in the caller's thread.
* <p>
* {@link StaleLocatorException}s are handled by the recursive application
* of <code>submit()</code>. These recursively submitted tasks are forced
* to run in the caller's thread by incrementing the
* {@link #getRecursionDepth()} counter. This is done to prevent the thread
* pool from becoming deadlocked as threads wait on threads handling stale
* locator retries. The deadlock situation arises as soon as all threads in
* the thread pool are waiting on stale locator retries as there are no
* threads remaining to process those retries.
*
* @param parallel
* <code>true</code> iff the tasks MAY be run in parallel.
* @param tasks
* The tasks to be executed.
*/
protected void runTasks(final boolean parallel,
final ArrayList<AbstractDataServiceProcedureTask> tasks) {
if (tasks.isEmpty()) {
log.warn("No tasks to run?", new RuntimeException(
"No tasks to run?"));
return;
}
if (getRecursionDepth().get() > 0) {
/*
* Force sequential execution of the tasks in the caller's thread.
*/
runInCallersThread(tasks);
} else if (tasks.size() == 1) {
runOne(tasks.get(0));
} else if (parallel) {
/*
* Map procedure across the index partitions in parallel.
*/
runParallel(tasks);
} else {
/*
* Sequential execution against of each split in turn.
*/
runSequence(tasks);
}
}
/**
* Maps a set of {@link DataServiceProcedureTask} tasks across the index
* partitions in strict sequence. The tasks are run on the
* {@link #getThreadPool()} so that sequential tasks never increase the
* total burden placed by the client above the size of that thread pool.
*
* @param tasks
* The tasks.
*/
protected void runOne(final Callable<Void> task) {
if (log.isInfoEnabled())
log.info("Running one task (#active="
+ getThreadPool().getActiveCount() + ", queueSize="
+ getThreadPool().getQueue().size() + ") : "
+ task.toString());
try {
final Future<Void> f = getThreadPool().submit(task);
// await completion of the task.
f.get(taskTimeout, TimeUnit.MILLISECONDS);
} catch (Exception e) {
if (log.isInfoEnabled())
log.info("Execution failed: task=" + task, e);
throw new ClientException("Execution failed: " + task,e);
}
}
/**
* Maps a set of {@link DataServiceProcedureTask} tasks across the index
* partitions in parallel.
*
* @param tasks
* The tasks.
*/
protected void runParallel(
final ArrayList<AbstractDataServiceProcedureTask> tasks) {
final long begin = System.currentTimeMillis();
if(log.isInfoEnabled())
log.info("Running " + tasks.size() + " tasks in parallel (#active="
+ getThreadPool().getActiveCount() + ", queueSize="
+ getThreadPool().getQueue().size() + ") : "
+ tasks.get(0).toString());
int nfailed = 0;
final LinkedList<Throwable> causes = new LinkedList<Throwable>();
try {
final List<Future<Void>> futures = getThreadPool().invokeAll(tasks,
taskTimeout, TimeUnit.MILLISECONDS);
final Iterator<Future<Void>> itr = futures.iterator();
int i = 0;
while(itr.hasNext()) {
final Future<Void> f = itr.next();
try {
f.get();
} catch (ExecutionException e) {
/*
* FIXME This needs to recognize when the remote task was
* cancelled by an interrupt and handle that condition
* appropriately. This is tricky since we are running
* multiple tasks in parallel. Probably we should interrupt
* any tasks which are still running and then through an
* InterruptedException wrapping the first exception whose
* root cause was an interrupt out to the caller.
*
* @see https://sourceforge.net/apps/trac/bigdata/ticket/479#comment:4
*/
final AbstractDataServiceProcedureTask task = tasks.get(i);
// log w/ stack trace so that we can see where this came
// from.
log.error("Execution failed: task=" + task, e);
if (task.causes != null) {
causes.addAll(task.causes);
} else {
causes.add(e);
}
nfailed++;
}
}
} catch (InterruptedException e) {
throw new RuntimeException("Interrupted: "+e);
}
if (nfailed > 0) {
throw new ClientException("Execution failed: ntasks="
+ tasks.size() + ", nfailed=" + nfailed, causes);
}
if (log.isInfoEnabled())
log.info("Ran " + tasks.size() + " tasks in parallel: elapsed="
+ (System.currentTimeMillis() - begin));
}
/**
* Maps a set of {@link DataServiceProcedureTask} tasks across the index
* partitions in strict sequence. The tasks are run on the
* {@link #getThreadPool()} so that sequential tasks never increase the
* total burden placed by the client above the size of that thread pool.
*
* @param tasks
* The tasks.
*/
protected void runSequence(final ArrayList<AbstractDataServiceProcedureTask> tasks) {
if (log.isInfoEnabled())
log.info("Running " + tasks.size() + " tasks in sequence (#active="
+ getThreadPool().getActiveCount() + ", queueSize="
+ getThreadPool().getQueue().size() + ") : "
+ tasks.get(0).toString());
final Iterator<AbstractDataServiceProcedureTask> itr = tasks.iterator();
while (itr.hasNext()) {
final AbstractDataServiceProcedureTask task = itr.next();
try {
final Future<Void> f = getThreadPool().submit(task);
// await completion of the task.
f.get(taskTimeout, TimeUnit.MILLISECONDS);
} catch (Exception e) {
if(log.isInfoEnabled()) log.info("Execution failed: task=" + task, e);
throw new ClientException("Execution failed: " + task, e, task.causes);
}
}
}
/**
* Executes the tasks in the caller's thread.
*
* @param tasks
* The tasks.
*/
protected void runInCallersThread(
final ArrayList<AbstractDataServiceProcedureTask> tasks) {
final int ntasks = tasks.size();
if (WARN && ntasks > 1)
log.warn("Running " + ntasks
+ " tasks in caller's thread: recursionDepth="
+ getRecursionDepth().get() + "(#active="
+ getThreadPool().getActiveCount() + ", queueSize="
+ getThreadPool().getQueue().size() + ") : "
+ tasks.get(0).toString());
final Iterator<AbstractDataServiceProcedureTask> itr = tasks.iterator();
while (itr.hasNext()) {
final AbstractDataServiceProcedureTask task = itr.next();
try {
task.call();
} catch (Exception e) {
// if (log.isInfoEnabled())
// log.info("Execution failed: task=" + task, e);
throw new ClientException("Execution failed: recursionDepth="
+ getRecursionDepth() + ", task=" + task, e,
task.causes);
}
}
}
@Override
public LinkedList<Split> splitKeys(long ts, int fromIndex, int toIndex,
byte[][] keys) {
return splitter.splitKeys(ts, fromIndex, toIndex, keys);
}
@Override
public LinkedList<Split> splitKeys(long ts, int fromIndex, int toIndex,
KVO[] a) {
return splitter.splitKeys(ts, fromIndex, toIndex, a);
}
// /**
// * {@inheritDoc}
// *
// * Find the partition for the first key. Check the last key, if it is in the
// * same partition then then this is the simplest case and we can just send
// * the data along.
// * <p>
// * Otherwise, perform a binary search on the remaining keys looking for the
// * index of the first key GTE the right separator key for that partition.
// * The batch for this partition is formed from all keys from the first key
// * for that partition up to but excluding the index position identified by
// * the binary search (if there is a match; if there is a miss, then the
// * binary search result needs to be converted into a key index and that will
// * be the last key for the current partition).
// * <p>
// * Examine the next key and repeat the process until all keys have been
// * allocated to index partitions.
// * <p>
// * Note: Split points MUST respect the "row" identity for a sparse row
// * store, but we get that constraint by maintaining the index partition
// * boundaries in agreement with the split point constraints for the index.
// *
// * @see Arrays#sort(Object[], int, int, java.util.Comparator)
// *
// * @see BytesUtil#compareBytes(byte[], byte[])
// *
// * @todo Caching? This procedure performs the minimum #of lookups using
// * {@link IMetadataIndex#find(byte[])} since that operation will be an
// * RMI in a distributed federation. The find(byte[] key) operation is
// * difficult to cache since it locates the index partition that would
// * span the key and many, many different keys could fit into that same
// * index partition. The only effective cache technique may be an LRU
// * that scans ~10 caches locators to see if any of them is a match
// * before reaching out to the remote {@link IMetadataService}. Or
// * perhaps the locators can be cached in a local BTree and a miss
// * there would result in a read through to the remote
// * {@link IMetadataService} but then we have the problem of figuring
// * out when to release locators if the client is long-lived.
// */
// public LinkedList<Split> splitKeys(final long ts, final int fromIndex,
// final int toIndex, final byte[][] keys) {
//
// assert keys != null;
//
// assert fromIndex >= 0;
// assert fromIndex < toIndex;
//
// assert toIndex <= keys.length;
//
// final LinkedList<Split> splits = new LinkedList<Split>();
//
// // start w/ the first key.
// int currentIndex = fromIndex;
//
// while (currentIndex < toIndex) {
//
// /*
// * This is partition spanning the current key (RMI)
// *
// * Note: Using the caller's timestamp here!
// */
// final PartitionLocator locator = fed.getMetadataIndex(name, ts)
// .find(keys[currentIndex]);
//
// if (locator == null)
// throw new RuntimeException("No index partitions?: name=" + name);
//
// final byte[] rightSeparatorKey = locator.getRightSeparatorKey();
//
// if (rightSeparatorKey == null) {
//
// /*
// * The last index partition does not have an upper bound and
// * will absorb any keys that order GTE to its left separator
// * key.
// */
//
// assert isValidSplit( locator, currentIndex, toIndex, keys );
//
// splits.add(new Split(locator, currentIndex, toIndex));
//
// // done.
// currentIndex = toIndex;
//
// } else {
//
// /*
// * Otherwise this partition has an upper bound, so figure out
// * the index of the last key that would go into this partition.
// *
// * We do this by searching for the rightSeparator of the index
// * partition itself.
// */
//
// int pos = BytesUtil.binarySearch(keys, currentIndex, toIndex
// - currentIndex, rightSeparatorKey);
//
// if (pos >= 0) {
//
// /*
// * There is a hit on the rightSeparator key. The index
// * returned by the binarySearch is the exclusive upper bound
// * for the split. The key at that index is excluded from the
// * split - it will be the first key in the next split.
// *
// * Note: There is a special case when the keys[] includes
// * duplicates of the key that corresponds to the
// * rightSeparator. This causes a problem where the
// * binarySearch returns the index of ONE of the keys that is
// * equal to the rightSeparator key and we need to back up
// * until we have found the FIRST ONE.
// *
// * Note: The behavior of the binarySearch is effectively
// * under-defined here and sometimes it will return the index
// * of the first key EQ to the rightSeparator while at other
// * times it will return the index of the second or greater
// * key that is EQ to the rightSeparatoer.
// */
//
// while (pos > currentIndex) {
//
// if (BytesUtil.bytesEqual(keys[pos - 1],
// rightSeparatorKey)) {
//
// // keep backing up.
// pos--;
//
// continue;
//
// }
//
// break;
//
// }
//
// if(log.isDebugEnabled()) log.debug("Exact match on rightSeparator: pos=" + pos
// + ", key=" + BytesUtil.toString(keys[pos]));
//
// } else if (pos < 0) {
//
// /*
// * There is a miss on the rightSeparator key (it is not
// * present in the keys that are being split). In this case
// * the binary search returns the insertion point. We then
// * compute the exclusive upper bound from the insertion
// * point.
// */
//
// pos = -pos - 1;
//
// assert pos > currentIndex && pos <= toIndex : "Expected pos in ["
// + currentIndex + ":" + toIndex + ") but pos=" + pos;
//
// }
//
// /*
// * Note: this test can be enabled if you are having problems
// * with KeyAfterPartition or KeyBeforePartition. It will go
// * through more effort to validate the constraints on the split.
// * However, due to the additional byte[] comparisons, this
// * SHOULD be disabled except when tracking a bug.
// */
//// assert validSplit( locator, currentIndex, pos, keys );
//
// splits.add(new Split(locator, currentIndex, pos));
//
// currentIndex = pos;
//
// }
//
// }
//
// return splits;
//
// }
//
// public LinkedList<Split> splitKeys(final long ts, final int fromIndex,
// final int toIndex, final KVO[] a) {
//
// /*
// * Change the shape of the data so that we can split it.
// */
//
// final byte[][] keys = new byte[a.length][];
//
// for (int i = 0; i < a.length; i++) {
//
// keys[i] = a[i].key;
//
// }
//
// return splitKeys(ts, fromIndex, toIndex, keys);
//
// }
//
// /**
// * Paranoia testing for generated splits.
// *
// * @param locator
// * @param fromIndex
// * @param toIndex
// * @param keys
// * @return
// */
// private boolean isValidSplit(final PartitionLocator locator,
// final int fromIndex, final int toIndex, final byte[][] keys) {
//
// assert fromIndex <= toIndex : "fromIndex=" + fromIndex + ", toIndex="
// + toIndex;
//
// assert fromIndex >= 0 : "fromIndex=" + fromIndex;
//
// assert toIndex <= keys.length : "toIndex=" + toIndex + ", keys.length="
// + keys.length;
//
// // begin with the left separator on the index partition.
// byte[] lastKey = locator.getLeftSeparatorKey();
//
// assert lastKey != null;
//
// for (int i = fromIndex; i < toIndex; i++) {
//
// final byte[] key = keys[i];
//
// assert key != null;
//
// if (lastKey != null) {
//
// final int ret = BytesUtil.compareBytes(lastKey, key);
//
// assert ret <= 0 : "keys out of order: i=" + i + ", lastKey="
// + BytesUtil.toString(lastKey) + ", key="
// + BytesUtil.toString(key)+", keys="+BytesUtil.toString(keys);
//
// }
//
// lastKey = key;
//
// }
//
// // Note: Must be strictly LT the rightSeparator key (when present).
// {
//
// final byte[] key = locator.getRightSeparatorKey();
//
// if (key != null) {
//
// int ret = BytesUtil.compareBytes(lastKey, key);
//
// assert ret < 0 : "keys out of order: lastKey="
// + BytesUtil.toString(lastKey) + ", rightSeparator="
// + BytesUtil.toString(key)+", keys="+BytesUtil.toString(keys);
//
// }
//
// }
//
// return true;
//
// }
@Override
public IDataService getDataService(final PartitionLocator pmd) {
return fed.getDataService(pmd.getDataServiceUUID());
}
/**
* This operation is not supported - the resource description of a scale-out
* index would include all "live" resources in the corresponding
* {@link MetadataIndex}.
*/
@Override
public IResourceMetadata[] getResourceMetadata() {
throw new UnsupportedOperationException();
}
@Override
public void staleLocator(final long ts, final PartitionLocator locator,
final StaleLocatorException cause) {
if (locator == null)
throw new IllegalArgumentException();
if (ts != ITx.UNISOLATED && ts != ITx.READ_COMMITTED) {
/*
* Stale locator exceptions should not be thrown for these views.
*/
throw new RuntimeException(
"Stale locator, but views should be consistent? timestamp="
+ TimestampUtility.toString(ts));
}
// notify the metadata index view that it has a stale locator.
fed.getMetadataIndex(name, timestamp).staleLocator(locator);
}
@Override
public <T extends IKeyArrayIndexProcedure, O, R, A> IRunnableBuffer<KVO<O>[]> newWriteBuffer(
final IResultHandler<R, A> resultHandler,
final IDuplicateRemover<O> duplicateRemover,
final AbstractKeyArrayIndexProcedureConstructor<T> ctor) {
final AsynchronousIndexWriteConfiguration conf = getIndexMetadata()
.getAsynchronousIndexWriteConfiguration();
final BlockingBuffer<KVO<O>[]> writeBuffer = new BlockingBuffer<KVO<O>[]>(
// @todo array vs linked w/ capacity and fair vs unfair.
// @todo config deque vs queue (deque combines on add() as well)
new LinkedBlockingDeque<KVO<O>[]>(conf.getMasterQueueCapacity()),
// new ArrayBlockingQueue<KVO<O>[]>(conf.getMasterQueueCapacity()),
conf.getMasterChunkSize(),//
conf.getMasterChunkTimeoutNanos(),//
TimeUnit.NANOSECONDS,//
true// ordered
);
final IndexWriteTask.M<T, O, R, A> task = new IndexWriteTask.M<T, O, R, A>(
this, //
conf.getSinkIdleTimeoutNanos(),//
conf.getSinkPollTimeoutNanos(),//
conf.getSinkQueueCapacity(), //
conf.getSinkChunkSize(), //
conf.getSinkChunkTimeoutNanos(),//
duplicateRemover,//
ctor,//
resultHandler,//
fed.getIndexCounters(name).asynchronousStats,
writeBuffer//
);
/**
* @see <a href="https://sourceforge.net/apps/trac/bigdata/ticket/707">
* BlockingBuffer.close() does not unblock threads </a>
*/
// Wrap computation as FutureTask.
@SuppressWarnings({ "unchecked", "rawtypes" })
final FutureTask<?> ft = new FutureTask(task);
// Set Future on BlockingBuffer.
writeBuffer.setFuture(ft);
// Submit computation for evaluation.
fed.getExecutorService().submit(ft);
return task.getBuffer();
}
/**
* Return a new {@link CounterSet} backed by the {@link ScaleOutIndexCounters}
* for this scale-out index.
*/
@Override
public CounterSet getCounters() {
return getFederation().getIndexCounters(name).getCounters();
}
}