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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.commitlog;
import java.io.*;
import java.util.*;
import java.util.concurrent.Future;
import java.util.concurrent.atomic.AtomicInteger;
import com.google.common.base.Predicate;
import com.google.common.collect.HashMultimap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Multimap;
import com.google.common.collect.Ordering;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.concurrent.Stage;
import org.apache.cassandra.concurrent.StageManager;
import org.apache.cassandra.config.Schema;
import org.apache.cassandra.db.*;
import org.apache.cassandra.io.util.FastByteArrayInputStream;
import org.apache.cassandra.io.util.FileUtils;
import org.apache.cassandra.io.util.RandomAccessReader;
import org.apache.cassandra.utils.*;
import org.cliffc.high_scale_lib.NonBlockingHashSet;
public class CommitLogReplayer
{
private static final Logger logger = LoggerFactory.getLogger(CommitLogReplayer.class);
private static final int MAX_OUTSTANDING_REPLAY_COUNT = 1024;
private static final int LEGACY_END_OF_SEGMENT_MARKER = 0;
private final Set<Keyspace> keyspacesRecovered;
private final List<Future<?>> futures;
private final Map<UUID, AtomicInteger> invalidMutations;
private final AtomicInteger replayedCount;
private final Map<UUID, ReplayPosition> cfPositions;
private final ReplayPosition globalPosition;
private final PureJavaCrc32 checksum;
private byte[] buffer;
public CommitLogReplayer()
{
this.keyspacesRecovered = new NonBlockingHashSet<Keyspace>();
this.futures = new ArrayList<Future<?>>();
this.buffer = new byte[4096];
this.invalidMutations = new HashMap<UUID, AtomicInteger>();
// count the number of replayed mutation. We don't really care about atomicity, but we need it to be a reference.
this.replayedCount = new AtomicInteger();
this.checksum = new PureJavaCrc32();
// compute per-CF and global replay positions
cfPositions = new HashMap<UUID, ReplayPosition>();
Ordering<ReplayPosition> replayPositionOrdering = Ordering.from(ReplayPosition.comparator);
for (ColumnFamilyStore cfs : ColumnFamilyStore.all())
{
// it's important to call RP.gRP per-cf, before aggregating all the positions w/ the Ordering.min call
// below: gRP will return NONE if there are no flushed sstables, which is important to have in the
// list (otherwise we'll just start replay from the first flush position that we do have, which is not correct).
ReplayPosition rp = ReplayPosition.getReplayPosition(cfs.getSSTables());
// but, if we've truncted the cf in question, then we need to need to start replay after the truncation
ReplayPosition truncatedAt = SystemKeyspace.getTruncatedPosition(cfs.metadata.cfId);
if (truncatedAt != null)
rp = replayPositionOrdering.max(Arrays.asList(rp, truncatedAt));
cfPositions.put(cfs.metadata.cfId, rp);
}
globalPosition = replayPositionOrdering.min(cfPositions.values());
logger.debug("Global replay position is {} from columnfamilies {}", globalPosition, FBUtilities.toString(cfPositions));
}
public void recover(File[] clogs) throws IOException
{
for (final File file : clogs)
recover(file);
}
public int blockForWrites()
{
for (Map.Entry<UUID, AtomicInteger> entry : invalidMutations.entrySet())
logger.info(String.format("Skipped %d mutations from unknown (probably removed) CF with id %s", entry.getValue().intValue(), entry.getKey()));
// wait for all the writes to finish on the mutation stage
FBUtilities.waitOnFutures(futures);
logger.debug("Finished waiting on mutations from recovery");
// flush replayed keyspaces
futures.clear();
for (Keyspace keyspace : keyspacesRecovered)
futures.addAll(keyspace.flush());
FBUtilities.waitOnFutures(futures);
return replayedCount.get();
}
private int readSyncMarker(CommitLogDescriptor descriptor, int offset, RandomAccessReader reader) throws IOException
{
if (offset > reader.length() - CommitLogSegment.SYNC_MARKER_SIZE)
{
if (offset != reader.length() && offset != Integer.MAX_VALUE)
logger.warn("Encountered bad header at position {} of Commit log {}; not enough room for a header", offset, reader.getPath());
// cannot possibly be a header here. if we're == length(), assume it's a correctly written final segment
return -1;
}
reader.seek(offset);
PureJavaCrc32 crc = new PureJavaCrc32();
crc.updateInt((int) (descriptor.id & 0xFFFFFFFFL));
crc.updateInt((int) (descriptor.id >>> 32));
crc.updateInt((int) reader.getPosition());
int end = reader.readInt();
long filecrc;
if (descriptor.version < CommitLogDescriptor.VERSION_21)
filecrc = reader.readLong();
else
filecrc = reader.readInt() & 0xffffffffL;
if (crc.getValue() != filecrc)
{
if (end != 0 || filecrc != 0)
{
logger.warn("Encountered bad header at position {} of commit log {}, with invalid CRC. The end of segment marker should be zero.", offset, reader.getPath());
}
return -1;
}
else if (end < offset || end > reader.length())
{
logger.warn("Encountered bad header at position {} of commit log {}, with bad position but valid CRC", offset, reader.getPath());
return -1;
}
return end;
}
private int getStartOffset(long segmentId, int version)
{
if (globalPosition.segment < segmentId)
{
if (version >= CommitLogDescriptor.VERSION_21)
return CommitLogDescriptor.HEADER_SIZE + CommitLogSegment.SYNC_MARKER_SIZE;
else
return 0;
}
else if (globalPosition.segment == segmentId)
return globalPosition.position;
else
return -1;
}
private abstract static class ReplayFilter
{
public abstract Iterable<ColumnFamily> filter(Mutation mutation);
public static ReplayFilter create()
{
// If no replaylist is supplied an empty array of strings is used to replay everything.
if (System.getProperty("cassandra.replayList") == null)
return new AlwaysReplayFilter();
Multimap<String, String> toReplay = HashMultimap.create();
for (String rawPair : System.getProperty("cassandra.replayList").split(","))
{
String[] pair = rawPair.trim().split("\\.");
if (pair.length != 2)
throw new IllegalArgumentException("Each table to be replayed must be fully qualified with keyspace name, e.g., 'system.peers'");
Keyspace ks = Schema.instance.getKeyspaceInstance(pair[0]);
if (ks == null)
throw new IllegalArgumentException("Unknown keyspace " + pair[0]);
if (ks.getColumnFamilyStore(pair[1]) == null)
throw new IllegalArgumentException(String.format("Unknown table %s.%s", pair[0], pair[1]));
toReplay.put(pair[0], pair[1]);
}
return new CustomReplayFilter(toReplay);
}
}
private static class AlwaysReplayFilter extends ReplayFilter
{
public Iterable<ColumnFamily> filter(Mutation mutation)
{
return mutation.getColumnFamilies();
}
}
private static class CustomReplayFilter extends ReplayFilter
{
private Multimap<String, String> toReplay;
public CustomReplayFilter(Multimap<String, String> toReplay)
{
this.toReplay = toReplay;
}
public Iterable<ColumnFamily> filter(Mutation mutation)
{
final Collection<String> cfNames = toReplay.get(mutation.getKeyspaceName());
if (cfNames == null)
return Collections.emptySet();
return Iterables.filter(mutation.getColumnFamilies(), new Predicate<ColumnFamily>()
{
public boolean apply(ColumnFamily cf)
{
return cfNames.contains(cf.metadata().cfName);
}
});
}
}
public void recover(File file) throws IOException
{
final ReplayFilter replayFilter = ReplayFilter.create();
logger.info("Replaying {}", file.getPath());
CommitLogDescriptor desc = CommitLogDescriptor.fromFileName(file.getName());
final long segmentId = desc.id;
logger.info("Replaying {} (CL version {}, messaging version {})",
file.getPath(),
desc.version,
desc.getMessagingVersion());
RandomAccessReader reader = RandomAccessReader.open(new File(file.getAbsolutePath()));
try
{
assert reader.length() <= Integer.MAX_VALUE;
int offset = getStartOffset(segmentId, desc.version);
if (offset < 0)
{
logger.debug("skipping replay of fully-flushed {}", file);
return;
}
int prevEnd = CommitLogDescriptor.HEADER_SIZE;
main: while (true)
{
int end = prevEnd;
if (desc.version < CommitLogDescriptor.VERSION_21)
end = Integer.MAX_VALUE;
else
{
do { end = readSyncMarker(desc, end, reader); }
while (end < offset && end > prevEnd);
}
if (end < prevEnd)
break;
if (logger.isDebugEnabled())
logger.debug("Replaying {} between {} and {}", file, offset, end);
reader.seek(offset);
/* read the logs populate Mutation and apply */
while (reader.getPosition() < end && !reader.isEOF())
{
if (logger.isDebugEnabled())
logger.debug("Reading mutation at {}", reader.getFilePointer());
long claimedCRC32;
int serializedSize;
try
{
// any of the reads may hit EOF
serializedSize = reader.readInt();
if (serializedSize == LEGACY_END_OF_SEGMENT_MARKER)
{
logger.debug("Encountered end of segment marker at {}", reader.getFilePointer());
break main;
}
// Mutation must be at LEAST 10 bytes:
// 3 each for a non-empty Keyspace and Key (including the
// 2-byte length from writeUTF/writeWithShortLength) and 4 bytes for column count.
// This prevents CRC by being fooled by special-case garbage in the file; see CASSANDRA-2128
if (serializedSize < 10)
break main;
long claimedSizeChecksum;
if (desc.version < CommitLogDescriptor.VERSION_21)
claimedSizeChecksum = reader.readLong();
else
claimedSizeChecksum = reader.readInt() & 0xffffffffL;
checksum.reset();
if (desc.version < CommitLogDescriptor.VERSION_20)
checksum.update(serializedSize);
else
checksum.updateInt(serializedSize);
if (checksum.getValue() != claimedSizeChecksum)
break main; // entry wasn't synced correctly/fully. that's
// ok.
if (serializedSize > buffer.length)
buffer = new byte[(int) (1.2 * serializedSize)];
reader.readFully(buffer, 0, serializedSize);
if (desc.version < CommitLogDescriptor.VERSION_21)
claimedCRC32 = reader.readLong();
else
claimedCRC32 = reader.readInt() & 0xffffffffL;
}
catch (EOFException eof)
{
break main; // last CL entry didn't get completely written. that's ok.
}
checksum.update(buffer, 0, serializedSize);
if (claimedCRC32 != checksum.getValue())
{
// this entry must not have been fsynced. probably the rest is bad too,
// but just in case there is no harm in trying them (since we still read on an entry boundary)
continue;
}
/* deserialize the commit log entry */
FastByteArrayInputStream bufIn = new FastByteArrayInputStream(buffer, 0, serializedSize);
final Mutation mutation;
try
{
mutation = Mutation.serializer.deserialize(new DataInputStream(bufIn),
desc.getMessagingVersion(),
ColumnSerializer.Flag.LOCAL);
// doublecheck that what we read is [still] valid for the current schema
for (ColumnFamily cf : mutation.getColumnFamilies())
for (Cell cell : cf)
cf.getComparator().validate(cell.name());
}
catch (UnknownColumnFamilyException ex)
{
if (ex.cfId == null)
continue;
AtomicInteger i = invalidMutations.get(ex.cfId);
if (i == null)
{
i = new AtomicInteger(1);
invalidMutations.put(ex.cfId, i);
}
else
i.incrementAndGet();
continue;
}
catch (Throwable t)
{
File f = File.createTempFile("mutation", "dat");
DataOutputStream out = new DataOutputStream(new FileOutputStream(f));
try
{
out.write(buffer, 0, serializedSize);
}
finally
{
out.close();
}
String st = String.format("Unexpected error deserializing mutation; saved to %s and ignored. This may be caused by replaying a mutation against a table with the same name but incompatible schema. Exception follows: ",
f.getAbsolutePath());
logger.error(st, t);
continue;
}
if (logger.isDebugEnabled())
logger.debug("replaying mutation for {}.{}: {}", mutation.getKeyspaceName(), ByteBufferUtil.bytesToHex(mutation.key()), "{" + StringUtils.join(mutation.getColumnFamilies().iterator(), ", ") + "}");
final long entryLocation = reader.getFilePointer();
Runnable runnable = new WrappedRunnable()
{
public void runMayThrow() throws IOException
{
if (Schema.instance.getKSMetaData(mutation.getKeyspaceName()) == null)
return;
if (pointInTimeExceeded(mutation))
return;
final Keyspace keyspace = Keyspace.open(mutation.getKeyspaceName());
// Rebuild the mutation, omitting column families that
// a) the user has requested that we ignore,
// b) have already been flushed,
// or c) are part of a cf that was dropped.
// Keep in mind that the cf.name() is suspect. do every thing based on the cfid instead.
Mutation newMutation = null;
for (ColumnFamily columnFamily : replayFilter.filter(mutation))
{
if (Schema.instance.getCF(columnFamily.id()) == null)
continue; // dropped
ReplayPosition rp = cfPositions.get(columnFamily.id());
// replay if current segment is newer than last flushed one or,
// if it is the last known segment, if we are after the replay position
if (segmentId > rp.segment || (segmentId == rp.segment && entryLocation > rp.position))
{
if (newMutation == null)
newMutation = new Mutation(mutation.getKeyspaceName(), mutation.key());
newMutation.add(columnFamily);
replayedCount.incrementAndGet();
}
}
if (newMutation != null)
{
assert !newMutation.isEmpty();
Keyspace.open(newMutation.getKeyspaceName()).apply(newMutation, false);
keyspacesRecovered.add(keyspace);
}
}
};
futures.add(StageManager.getStage(Stage.MUTATION).submit(runnable));
if (futures.size() > MAX_OUTSTANDING_REPLAY_COUNT)
{
FBUtilities.waitOnFutures(futures);
futures.clear();
}
}
if (desc.version < CommitLogDescriptor.VERSION_21)
break;
offset = end + CommitLogSegment.SYNC_MARKER_SIZE;
prevEnd = end;
}
}
finally
{
FileUtils.closeQuietly(reader);
logger.info("Finished reading {}", file);
}
}
protected boolean pointInTimeExceeded(Mutation fm)
{
long restoreTarget = CommitLog.instance.archiver.restorePointInTime;
for (ColumnFamily families : fm.getColumnFamilies())
{
if (CommitLog.instance.archiver.precision.toMillis(families.maxTimestamp()) > restoreTarget)
return true;
}
return false;
}
}