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* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
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package org.apache.cassandra.db.view;
import java.util.Collection;
import java.util.Collections;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import javax.annotation.Nullable;
import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.concurrent.ScheduledExecutors;
import org.apache.cassandra.db.*;
import org.apache.cassandra.db.compaction.CompactionInfo;
import org.apache.cassandra.db.compaction.CompactionManager;
import org.apache.cassandra.db.compaction.OperationType;
import org.apache.cassandra.db.lifecycle.SSTableSet;
import org.apache.cassandra.db.partitions.*;
import org.apache.cassandra.db.rows.*;
import org.apache.cassandra.dht.Range;
import org.apache.cassandra.dht.Token;
import org.apache.cassandra.io.sstable.ReducingKeyIterator;
import org.apache.cassandra.io.sstable.format.SSTableReader;
import org.apache.cassandra.service.StorageProxy;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.service.pager.QueryPager;
import org.apache.cassandra.transport.Server;
import org.apache.cassandra.utils.FBUtilities;
import org.apache.cassandra.utils.Pair;
import org.apache.cassandra.utils.UUIDGen;
import org.apache.cassandra.utils.concurrent.Refs;
public class ViewBuilder extends CompactionInfo.Holder
{
private final ColumnFamilyStore baseCfs;
private final View view;
private final UUID compactionId;
private volatile Token prevToken = null;
private static final Logger logger = LoggerFactory.getLogger(ViewBuilder.class);
private volatile boolean isStopped = false;
public ViewBuilder(ColumnFamilyStore baseCfs, View view)
{
this.baseCfs = baseCfs;
this.view = view;
compactionId = UUIDGen.getTimeUUID();
}
private void buildKey(DecoratedKey key)
{
AtomicLong noBase = new AtomicLong(Long.MAX_VALUE);
ReadQuery selectQuery = view.getReadQuery();
if (!selectQuery.selectsKey(key))
return;
int nowInSec = FBUtilities.nowInSeconds();
SinglePartitionReadCommand command = view.getSelectStatement().internalReadForView(key, nowInSec);
// We're rebuilding everything from what's on disk, so we read everything, consider that as new updates
// and pretend that there is nothing pre-existing.
UnfilteredRowIterator empty = UnfilteredRowIterators.noRowsIterator(baseCfs.metadata, key, Rows.EMPTY_STATIC_ROW, DeletionTime.LIVE, false);
Collection<Mutation> mutations;
try (ReadOrderGroup orderGroup = command.startOrderGroup();
UnfilteredRowIterator data = UnfilteredPartitionIterators.getOnlyElement(command.executeLocally(orderGroup), command))
{
mutations = baseCfs.keyspace.viewManager.forTable(baseCfs.metadata).generateViewUpdates(Collections.singleton(view), data, empty, nowInSec);
}
if (!mutations.isEmpty())
StorageProxy.mutateMV(key.getKey(), mutations, true, noBase);
}
public void run()
{
String ksname = baseCfs.metadata.ksName, viewName = view.name;
if (SystemKeyspace.isViewBuilt(ksname, viewName))
return;
Iterable<Range<Token>> ranges = StorageService.instance.getLocalRanges(baseCfs.metadata.ksName);
final Pair<Integer, Token> buildStatus = SystemKeyspace.getViewBuildStatus(ksname, viewName);
Token lastToken;
Function<org.apache.cassandra.db.lifecycle.View, Iterable<SSTableReader>> function;
if (buildStatus == null)
{
baseCfs.forceBlockingFlush();
function = org.apache.cassandra.db.lifecycle.View.selectFunction(SSTableSet.CANONICAL);
int generation = Integer.MIN_VALUE;
try (Refs<SSTableReader> temp = baseCfs.selectAndReference(function).refs)
{
for (SSTableReader reader : temp)
{
generation = Math.max(reader.descriptor.generation, generation);
}
}
SystemKeyspace.beginViewBuild(ksname, viewName, generation);
lastToken = null;
}
else
{
function = new Function<org.apache.cassandra.db.lifecycle.View, Iterable<SSTableReader>>()
{
@Nullable
public Iterable<SSTableReader> apply(org.apache.cassandra.db.lifecycle.View view)
{
Iterable<SSTableReader> readers = org.apache.cassandra.db.lifecycle.View.selectFunction(SSTableSet.CANONICAL).apply(view);
if (readers != null)
return Iterables.filter(readers, ssTableReader -> ssTableReader.descriptor.generation <= buildStatus.left);
return null;
}
};
lastToken = buildStatus.right;
}
prevToken = lastToken;
try (Refs<SSTableReader> sstables = baseCfs.selectAndReference(function).refs;
ReducingKeyIterator iter = new ReducingKeyIterator(sstables))
{
while (!isStopped && iter.hasNext())
{
DecoratedKey key = iter.next();
Token token = key.getToken();
if (lastToken == null || lastToken.compareTo(token) < 0)
{
for (Range<Token> range : ranges)
{
if (range.contains(token))
{
buildKey(key);
if (prevToken == null || prevToken.compareTo(token) != 0)
{
SystemKeyspace.updateViewBuildStatus(ksname, viewName, key.getToken());
prevToken = token;
}
}
}
lastToken = null;
}
}
if (!isStopped)
SystemKeyspace.finishViewBuildStatus(ksname, viewName);
}
catch (Exception e)
{
final ViewBuilder builder = new ViewBuilder(baseCfs, view);
ScheduledExecutors.nonPeriodicTasks.schedule(() -> CompactionManager.instance.submitViewBuilder(builder),
5,
TimeUnit.MINUTES);
logger.warn("Materialized View failed to complete, sleeping 5 minutes before restarting", e);
}
}
public CompactionInfo getCompactionInfo()
{
long rangesLeft = 0, rangesTotal = 0;
Token lastToken = prevToken;
// This approximation is not very accurate, but since we do not have a method which allows us to calculate the
// percentage of a range covered by a second range, this is the best approximation that we can calculate.
// Instead, we just count the total number of ranges that haven't been seen by the node (we use the order of
// the tokens to determine whether they have been seen yet or not), and the total number of ranges that a node
// has.
for (Range<Token> range : StorageService.instance.getLocalRanges(baseCfs.keyspace.getName()))
{
rangesLeft++;
rangesTotal++;
// This will reset rangesLeft, so that the number of ranges left will be less than the total ranges at the
// end of the method.
if (lastToken == null || range.contains(lastToken))
rangesLeft = 0;
}
return new CompactionInfo(baseCfs.metadata, OperationType.VIEW_BUILD, rangesLeft, rangesTotal, "ranges", compactionId);
}
public void stop()
{
isStopped = true;
}
}