/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* 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.
*/
package org.apache.cassandra.service;
import java.io.*;
import java.net.InetAddress;
import java.security.MessageDigest;
import java.util.*;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.Condition;
import com.google.common.base.Objects;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.concurrent.*;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.db.ColumnFamilyStore;
import org.apache.cassandra.db.compaction.AbstractCompactedRow;
import org.apache.cassandra.db.compaction.CompactionManager;
import org.apache.cassandra.db.DecoratedKey;
import org.apache.cassandra.db.Table;
import org.apache.cassandra.dht.AbstractBounds;
import org.apache.cassandra.dht.RandomPartitioner;
import org.apache.cassandra.dht.Range;
import org.apache.cassandra.gms.*;
import org.apache.cassandra.io.ICompactSerializer;
import org.apache.cassandra.io.sstable.SSTableReader;
import org.apache.cassandra.net.CompactEndpointSerializationHelper;
import org.apache.cassandra.net.IVerbHandler;
import org.apache.cassandra.net.Message;
import org.apache.cassandra.net.MessagingService;
import org.apache.cassandra.streaming.OperationType;
import org.apache.cassandra.streaming.StreamIn;
import org.apache.cassandra.streaming.StreamOut;
import org.apache.cassandra.streaming.StreamOutSession;
import org.apache.cassandra.utils.*;
/**
* AntiEntropyService encapsulates "validating" (hashing) individual column families,
* exchanging MerkleTrees with remote nodes via a TreeRequest/Response conversation,
* and then triggering repairs for disagreeing ranges.
*
* Every Tree conversation has an 'initiator', where valid trees are sent after generation
* and where the local and remote tree will rendezvous in rendezvous(cf, endpoint, tree).
* Once the trees rendezvous, a Differencer is executed and the service can trigger repairs
* for disagreeing ranges.
*
* Tree comparison and repair triggering occur in the single threaded Stage.ANTIENTROPY.
*
* The steps taken to enact a repair are as follows:
* 1. A major compaction is triggered via nodeprobe:
* * Nodeprobe sends TreeRequest messages to all neighbors of the target node: when a node
* receives a TreeRequest, it will perform a readonly compaction to immediately validate
* the column family.
* 2. The compaction process validates the column family by:
* * Calling Validator.prepare(), which samples the column family to determine key distribution,
* * Calling Validator.add() in order for every row in the column family,
* * Calling Validator.complete() to indicate that all rows have been added.
* * Calling complete() indicates that a valid MerkleTree has been created for the column family.
* * The valid tree is returned to the requesting node via a TreeResponse.
* 3. When a node receives a TreeResponse, it passes the tree to rendezvous(), which checks for trees to
* rendezvous with / compare to:
* * If the tree is local, it is cached, and compared to any trees that were received from neighbors.
* * If the tree is remote, it is immediately compared to a local tree if one is cached. Otherwise,
* the remote tree is stored until a local tree can be generated.
* * A Differencer object is enqueued for each comparison.
* 4. Differencers are executed in Stage.ANTIENTROPY, to compare the two trees, and perform repair via the
* streaming api.
*/
public class AntiEntropyService
{
private static final Logger logger = LoggerFactory.getLogger(AntiEntropyService.class);
// singleton enforcement
public static final AntiEntropyService instance = new AntiEntropyService();
private static final ThreadPoolExecutor executor;
static
{
executor = new JMXConfigurableThreadPoolExecutor(4,
60,
TimeUnit.SECONDS,
new LinkedBlockingQueue<Runnable>(),
new NamedThreadFactory("AntiEntropySessions"),
"internal");
}
/**
* A map of active session.
*/
private final ConcurrentMap<String, RepairSession> sessions;
/**
* Protected constructor. Use AntiEntropyService.instance.
*/
protected AntiEntropyService()
{
sessions = new ConcurrentHashMap<String, RepairSession>();
}
/**
* Requests repairs for the given table and column families, and blocks until all repairs have been completed.
*/
public RepairFuture submitRepairSession(Range range, String tablename, String... cfnames)
{
RepairFuture futureTask = new RepairSession(range, tablename, cfnames).getFuture();
executor.execute(futureTask);
return futureTask;
}
RepairFuture submitArtificialRepairSession(TreeRequest req, String tablename, String... cfnames)
{
RepairFuture futureTask = new RepairSession(req, tablename, cfnames).getFuture();
executor.execute(futureTask);
return futureTask;
}
/**
* Return all of the neighbors with whom we share data.
*/
static Set<InetAddress> getNeighbors(String table, Range range)
{
StorageService ss = StorageService.instance;
Map<Range, List<InetAddress>> replicaSets = ss.getRangeToAddressMap(table);
if (!replicaSets.containsKey(range))
return Collections.emptySet();
Set<InetAddress> neighbors = new HashSet<InetAddress>(replicaSets.get(range));
neighbors.remove(FBUtilities.getLocalAddress());
// Excluding all node with version <= 0.7 since they don't know how to
// create a correct merkle tree (they build it over the full range)
Iterator<InetAddress> iter = neighbors.iterator();
while (iter.hasNext())
{
InetAddress endpoint = iter.next();
if (Gossiper.instance.getVersion(endpoint) <= MessagingService.VERSION_07)
{
logger.info("Excluding " + endpoint + " from repair because it is on version 0.7 or sooner. You should consider updating this node before running repair again.");
iter.remove();
}
}
return neighbors;
}
/**
* Register a tree for the given request to be compared to the appropriate trees in Stage.ANTIENTROPY when they become available.
*/
private void rendezvous(TreeRequest request, MerkleTree tree)
{
RepairSession session = sessions.get(request.sessionid);
assert session != null;
RepairSession.RepairJob job = session.jobs.peek();
assert job != null : "A repair should have at least some jobs scheduled";
if (job.addTree(request, tree) == 0)
{
logger.debug("All trees received for " + session.getName() + "/" + request.cf.right);
job.submitDifferencers();
// This job is complete, switching to next in line (note that only
// one thread will can ever do this)
session.jobs.poll();
RepairSession.RepairJob nextJob = session.jobs.peek();
if (nextJob == null)
// We are done with this repair session as far as differencing
// is considern. Just inform the session
session.differencingDone.signalAll();
else
nextJob.sendTreeRequests();
}
}
/**
* Requests a tree from the given node, and returns the request that was sent.
*/
TreeRequest request(String sessionid, InetAddress remote, Range range, String ksname, String cfname)
{
TreeRequest request = new TreeRequest(sessionid, remote, range, new CFPair(ksname, cfname));
MessagingService.instance().sendOneWay(TreeRequestVerbHandler.makeVerb(request, Gossiper.instance.getVersion(remote)), remote);
return request;
}
/**
* Responds to the node that requested the given valid tree.
* @param validator A locally generated validator
* @param local localhost (parameterized for testing)
*/
void respond(Validator validator, InetAddress local)
{
MessagingService ms = MessagingService.instance();
try
{
Message message = TreeResponseVerbHandler.makeVerb(local, validator);
logger.info("Sending AEService tree for " + validator.request);
ms.sendOneWay(message, validator.request.endpoint);
}
catch (Exception e)
{
logger.error("Could not send valid tree for request " + validator.request, e);
}
}
/**
* A Strategy to handle building and validating a merkle tree for a column family.
*
* Lifecycle:
* 1. prepare() - Initialize tree with samples.
* 2. add() - 0 or more times, to add hashes to the tree.
* 3. complete() - Enqueues any operations that were blocked waiting for a valid tree.
*/
public static class Validator implements Runnable
{
public final TreeRequest request;
public final MerkleTree tree;
// the minimum token sorts first, but falls into the last range
private transient List<MerkleTree.RowHash> minrows;
// null when all rows with the min token have been consumed
private transient long validated;
private transient MerkleTree.TreeRange range;
private transient MerkleTree.TreeRangeIterator ranges;
private transient DecoratedKey lastKey;
public final static MerkleTree.RowHash EMPTY_ROW = new MerkleTree.RowHash(null, new byte[0]);
Validator(TreeRequest request)
{
this(request,
// TODO: memory usage (maxsize) should either be tunable per
// CF, globally, or as shared for all CFs in a cluster
new MerkleTree(DatabaseDescriptor.getPartitioner(), request.range, MerkleTree.RECOMMENDED_DEPTH, (int)Math.pow(2, 15)));
}
Validator(TreeRequest request, MerkleTree tree)
{
this.request = request;
this.tree = tree;
// Reestablishing the range because we don't serialize it (for bad
// reason - see MerkleTree for details)
this.tree.fullRange = this.request.range;
minrows = new ArrayList<MerkleTree.RowHash>();
validated = 0;
range = null;
ranges = null;
}
public void prepare(ColumnFamilyStore cfs)
{
if (tree.partitioner() instanceof RandomPartitioner)
{
// You can't beat an even tree distribution for md5
tree.init();
}
else
{
List<DecoratedKey> keys = new ArrayList<DecoratedKey>();
for (DecoratedKey sample : cfs.keySamples(request.range))
{
assert request.range.contains(sample.token);
keys.add(sample);
}
if (keys.isEmpty())
{
// use an even tree distribution
tree.init();
}
else
{
int numkeys = keys.size();
Random random = new Random();
// sample the column family using random keys from the index
while (true)
{
DecoratedKey dk = keys.get(random.nextInt(numkeys));
if (!tree.split(dk.token))
break;
}
}
}
logger.debug("Prepared AEService tree of size " + tree.size() + " for " + request);
ranges = tree.invalids();
}
/**
* Called (in order) for every row present in the CF.
* Hashes the row, and adds it to the tree being built.
*
* There are four possible cases:
* 1. Token is greater than range.right (we haven't generated a range for it yet),
* 2. Token is less than/equal to range.left (the range was valid),
* 3. Token is contained in the range (the range is in progress),
* 4. No more invalid ranges exist.
*
* TODO: Because we only validate completely empty trees at the moment, we
* do not bother dealing with case 2 and case 4 should result in an error.
*
* Additionally, there is a special case for the minimum token, because
* although it sorts first, it is contained in the last possible range.
*
* @param row The row.
*/
public void add(AbstractCompactedRow row)
{
assert request.range.contains(row.key.token) : row.key.token + " is not contained in " + request.range;
assert lastKey == null || lastKey.compareTo(row.key) < 0
: "row " + row.key + " received out of order wrt " + lastKey;
lastKey = row.key;
if (range == null)
range = ranges.next();
// generate new ranges as long as case 1 is true
while (!range.contains(row.key.token))
{
// add the empty hash, and move to the next range
range.addHash(EMPTY_ROW);
range = ranges.next();
}
// case 3 must be true: mix in the hashed row
range.addHash(rowHash(row));
}
private MerkleTree.RowHash rowHash(AbstractCompactedRow row)
{
validated++;
// MerkleTree uses XOR internally, so we want lots of output bits here
MessageDigest digest = FBUtilities.newMessageDigest("SHA-256");
row.update(digest);
return new MerkleTree.RowHash(row.key.token, digest.digest());
}
/**
* Registers the newly created tree for rendezvous in Stage.ANTIENTROPY.
*/
public void complete()
{
completeTree();
StageManager.getStage(Stage.ANTI_ENTROPY).execute(this);
logger.debug("Validated " + validated + " rows into AEService tree for " + request);
}
void completeTree()
{
assert ranges != null : "Validator was not prepared()";
if (range != null)
range.addHash(EMPTY_ROW);
while (ranges.hasNext())
{
range = ranges.next();
range.addHash(EMPTY_ROW);
}
}
/**
* Called after the validation lifecycle to respond with the now valid tree. Runs in Stage.ANTIENTROPY.
*
* @return A meaningless object.
*/
public void run()
{
// respond to the request that triggered this validation
AntiEntropyService.instance.respond(this, FBUtilities.getLocalAddress());
}
}
/**
* Handler for requests from remote nodes to generate a valid tree.
* The payload is a CFPair representing the columnfamily to validate.
*/
public static class TreeRequestVerbHandler implements IVerbHandler, ICompactSerializer<TreeRequest>
{
public static final TreeRequestVerbHandler SERIALIZER = new TreeRequestVerbHandler();
static Message makeVerb(TreeRequest request, int version)
{
try
{
ByteArrayOutputStream bos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(bos);
SERIALIZER.serialize(request, dos, version);
return new Message(FBUtilities.getLocalAddress(), StorageService.Verb.TREE_REQUEST, bos.toByteArray(), version);
}
catch(IOException e)
{
throw new RuntimeException(e);
}
}
public void serialize(TreeRequest request, DataOutputStream dos, int version) throws IOException
{
dos.writeUTF(request.sessionid);
CompactEndpointSerializationHelper.serialize(request.endpoint, dos);
dos.writeUTF(request.cf.left);
dos.writeUTF(request.cf.right);
if (version > MessagingService.VERSION_07)
AbstractBounds.serializer().serialize(request.range, dos);
}
public TreeRequest deserialize(DataInputStream dis, int version) throws IOException
{
String sessId = dis.readUTF();
InetAddress endpoint = CompactEndpointSerializationHelper.deserialize(dis);
CFPair cfpair = new CFPair(dis.readUTF(), dis.readUTF());
Range range;
if (version > MessagingService.VERSION_07)
range = (Range) AbstractBounds.serializer().deserialize(dis);
else
range = new Range(StorageService.getPartitioner().getMinimumToken(), StorageService.getPartitioner().getMinimumToken());
return new TreeRequest(sessId, endpoint, range, cfpair);
}
/**
* Trigger a validation compaction which will return the tree upon completion.
*/
public void doVerb(Message message, String id)
{
byte[] bytes = message.getMessageBody();
DataInputStream buffer = new DataInputStream(new ByteArrayInputStream(bytes));
try
{
TreeRequest remotereq = this.deserialize(buffer, message.getVersion());
TreeRequest request = new TreeRequest(remotereq.sessionid, message.getFrom(), remotereq.range, remotereq.cf);
// trigger readonly-compaction
ColumnFamilyStore store = Table.open(request.cf.left).getColumnFamilyStore(request.cf.right);
Validator validator = new Validator(request);
logger.debug("Queueing validation compaction for " + request);
CompactionManager.instance.submitValidation(store, validator);
}
catch (IOException e)
{
throw new IOError(e);
}
}
}
/**
* Handler for responses from remote nodes which contain a valid tree.
* The payload is a completed Validator object from the remote endpoint.
*/
public static class TreeResponseVerbHandler implements IVerbHandler, ICompactSerializer<Validator>
{
public static final TreeResponseVerbHandler SERIALIZER = new TreeResponseVerbHandler();
static Message makeVerb(InetAddress local, Validator validator)
{
try
{
ByteArrayOutputStream bos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(bos);
SERIALIZER.serialize(validator, dos, Gossiper.instance.getVersion(validator.request.endpoint));
return new Message(local,
StorageService.Verb.TREE_RESPONSE,
bos.toByteArray(),
Gossiper.instance.getVersion(validator.request.endpoint));
}
catch(IOException e)
{
throw new RuntimeException(e);
}
}
public void serialize(Validator v, DataOutputStream dos, int version) throws IOException
{
TreeRequestVerbHandler.SERIALIZER.serialize(v.request, dos, version);
MerkleTree.serializer.serialize(v.tree, dos, version);
dos.flush();
}
public Validator deserialize(DataInputStream dis, int version) throws IOException
{
final TreeRequest request = TreeRequestVerbHandler.SERIALIZER.deserialize(dis, version);
try
{
return new Validator(request, MerkleTree.serializer.deserialize(dis, version));
}
catch(Exception e)
{
throw new RuntimeException(e);
}
}
public void doVerb(Message message, String id)
{
byte[] bytes = message.getMessageBody();
DataInputStream buffer = new DataInputStream(new ByteArrayInputStream(bytes));
try
{
// deserialize the remote tree, and register it
Validator response = this.deserialize(buffer, message.getVersion());
TreeRequest request = new TreeRequest(response.request.sessionid, message.getFrom(), response.request.range, response.request.cf);
AntiEntropyService.instance.rendezvous(request, response.tree);
}
catch (IOException e)
{
throw new IOError(e);
}
}
}
/**
* A tuple of table and cf.
*/
static class CFPair extends Pair<String,String>
{
public CFPair(String table, String cf)
{
super(table, cf);
assert table != null && cf != null;
}
}
/**
* A tuple of a local and remote tree.
*/
static class TreePair extends Pair<MerkleTree,MerkleTree>
{
public TreePair(MerkleTree local, MerkleTree remote)
{
super(local, remote);
}
}
/**
* A tuple of table, cf, address and range that represents a location we have an outstanding TreeRequest for.
*/
public static class TreeRequest
{
public final String sessionid;
public final InetAddress endpoint;
public final Range range;
public final CFPair cf;
public TreeRequest(String sessionid, InetAddress endpoint, Range range, CFPair cf)
{
this.sessionid = sessionid;
this.endpoint = endpoint;
this.cf = cf;
this.range = range;
}
@Override
public final int hashCode()
{
return Objects.hashCode(sessionid, endpoint, cf, range);
}
@Override
public final boolean equals(Object o)
{
if(!(o instanceof TreeRequest))
return false;
TreeRequest that = (TreeRequest)o;
// handles nulls properly
return Objects.equal(sessionid, that.sessionid) && Objects.equal(endpoint, that.endpoint) && Objects.equal(cf, that.cf) && Objects.equal(range, that.range);
}
@Override
public String toString()
{
return "#<TreeRequest " + sessionid + ", " + endpoint + ", " + cf + ", " + range + ">";
}
}
/**
* Triggers repairs with all neighbors for the given table, cfs and range.
* Typical lifecycle is: start() then join(). Executed in client threads.
*/
class RepairSession extends WrappedRunnable implements IEndpointStateChangeSubscriber, IFailureDetectionEventListener
{
private final String sessionName;
private final String tablename;
private final String[] cfnames;
private final Range range;
private volatile Exception exception;
private final AtomicBoolean isFailed = new AtomicBoolean(false);
private final Set<InetAddress> endpoints;
final Queue<RepairJob> jobs = new ConcurrentLinkedQueue<RepairJob>();
final Map<String, RepairJob> activeJobs = new ConcurrentHashMap<String, RepairJob>();
private final SimpleCondition completed = new SimpleCondition();
public final Condition differencingDone = new SimpleCondition();
public RepairSession(TreeRequest req, String tablename, String... cfnames)
{
this(req.sessionid, req.range, tablename, cfnames);
AntiEntropyService.instance.sessions.put(getName(), this);
}
public RepairSession(Range range, String tablename, String... cfnames)
{
this("manual-repair-" + UUID.randomUUID(), range, tablename, cfnames);
}
private RepairSession(String id, Range range, String tablename, String[] cfnames)
{
this.sessionName = id;
this.tablename = tablename;
this.cfnames = cfnames;
assert cfnames.length > 0 : "Repairing no column families seems pointless, doesn't it";
this.range = range;
this.endpoints = AntiEntropyService.getNeighbors(tablename, range);
}
public String getName()
{
return sessionName;
}
RepairFuture getFuture()
{
return new RepairFuture(this);
}
// we don't care about the return value but care about it throwing exception
public void runMayThrow() throws Exception
{
if (endpoints.isEmpty())
{
differencingDone.signalAll();
logger.info("No neighbors to repair with for " + tablename + " on " + range + ": " + getName() + " completed.");
return;
}
// Checking all nodes are live
for (InetAddress endpoint : endpoints)
{
if (!FailureDetector.instance.isAlive(endpoint))
{
differencingDone.signalAll();
logger.info("Could not proceed on repair because a neighbor (" + endpoint + ") is dead: " + getName() + " failed.");
return;
}
}
AntiEntropyService.instance.sessions.put(getName(), this);
Gossiper.instance.register(this);
FailureDetector.instance.registerFailureDetectionEventListener(this);
try
{
// Create and queue a RepairJob for each column family
for (String cfname : cfnames)
{
RepairJob job = new RepairJob(cfname);
jobs.offer(job);
activeJobs.put(cfname, job);
}
jobs.peek().sendTreeRequests();
// block whatever thread started this session until all requests have been returned:
// if this thread dies, the session will still complete in the background
completed.await();
if (exception != null)
throw exception;
}
catch (InterruptedException e)
{
throw new RuntimeException("Interrupted while waiting for repair: repair will continue in the background.");
}
finally
{
FailureDetector.instance.unregisterFailureDetectionEventListener(this);
Gossiper.instance.unregister(this);
AntiEntropyService.instance.sessions.remove(getName());
}
}
void completed(InetAddress remote, String cfname)
{
logger.debug("Repair completed for {} on {}", remote, cfname);
RepairJob job = activeJobs.get(cfname);
if (job.completedSynchronizationJob(remote))
{
activeJobs.remove(cfname);
if (activeJobs.isEmpty())
completed.signalAll();
}
}
void failedNode(InetAddress remote)
{
String errorMsg = String.format("Problem during repair session %s, endpoint %s died", sessionName, remote);
logger.error(errorMsg);
exception = new IOException(errorMsg);
// If a node failed, we stop everything (though there could still be some activity in the background)
jobs.clear();
activeJobs.clear();
differencingDone.signalAll();
completed.signalAll();
}
public void onJoin(InetAddress endpoint, EndpointState epState) {}
public void onChange(InetAddress endpoint, ApplicationState state, VersionedValue value) {}
public void onAlive(InetAddress endpoint, EndpointState state) {}
public void onDead(InetAddress endpoint, EndpointState state) {}
public void onRemove(InetAddress endpoint)
{
convict(endpoint, Double.MAX_VALUE);
}
public void onRestart(InetAddress endpoint, EndpointState epState)
{
convict(endpoint, Double.MAX_VALUE);
}
public void convict(InetAddress endpoint, double phi)
{
if (!endpoints.contains(endpoint))
return;
// We want a higher confidence in the failure detection than usual because failing a repair wrongly has a high cost.
if (phi < 2 * DatabaseDescriptor.getPhiConvictThreshold())
return;
// Though unlikely, it is possible to arrive here multiple time and we
// want to avoid print an error message twice
if (!isFailed.compareAndSet(false, true))
return;
failedNode(endpoint);
}
class RepairJob
{
private final String cfname;
private final Set<InetAddress> requestedEndpoints = new HashSet<InetAddress>();
private final Map<InetAddress, MerkleTree> trees = new HashMap<InetAddress, MerkleTree>();
private final Set<InetAddress> syncJobs = new HashSet<InetAddress>();
public RepairJob(String cfname)
{
this.cfname = cfname;
}
/**
* Send merkle tree request to every involved neighbor.
*/
public void sendTreeRequests()
{
requestedEndpoints.addAll(endpoints);
requestedEndpoints.add(FBUtilities.getLocalAddress());
// send requests to all nodes
for (InetAddress endpoint : requestedEndpoints)
AntiEntropyService.instance.request(getName(), endpoint, range, tablename, cfname);
}
/**
* Add a new received tree and return the number of remaining tree to
* be received for the job to be complete.
*/
public synchronized int addTree(TreeRequest request, MerkleTree tree)
{
assert request.cf.right.equals(cfname);
trees.put(request.endpoint, tree);
requestedEndpoints.remove(request.endpoint);
return requestedEndpoints.size();
}
/**
* Submit differencers for running.
* All tree *must* have been received before this is called.
*/
public void submitDifferencers()
{
assert requestedEndpoints.size() == 0;
// Right now, we only difference local host against each other. CASSANDRA-2610 will fix that.
// In the meantime ugly special casing will work good enough.
MerkleTree localTree = trees.get(FBUtilities.getLocalAddress());
assert localTree != null;
for (Map.Entry<InetAddress, MerkleTree> entry : trees.entrySet())
{
if (entry.getKey().equals(FBUtilities.getLocalAddress()))
continue;
Differencer differencer = new Differencer(cfname, entry.getKey(), entry.getValue(), localTree);
syncJobs.add(entry.getKey());
logger.debug("Queueing comparison " + differencer);
StageManager.getStage(Stage.ANTI_ENTROPY).execute(differencer);
}
trees.clear(); // allows gc to do its thing
}
synchronized boolean completedSynchronizationJob(InetAddress remote)
{
syncJobs.remove(remote);
return syncJobs.isEmpty();
}
}
/**
* Runs on the node that initiated a request to compare two trees, and launch repairs for disagreeing ranges.
*/
class Differencer implements Runnable
{
public final String cfname;
public final InetAddress remote;
public final MerkleTree ltree;
public final MerkleTree rtree;
public List<Range> differences;
Differencer(String cfname, InetAddress remote, MerkleTree ltree, MerkleTree rtree)
{
this.cfname = cfname;
this.remote = remote;
this.ltree = ltree;
this.rtree = rtree;
this.differences = new ArrayList<Range>();
}
/**
* Compares our trees, and triggers repairs for any ranges that mismatch.
*/
public void run()
{
InetAddress local = FBUtilities.getLocalAddress();
// restore partitioners (in case we were serialized)
if (ltree.partitioner() == null)
ltree.partitioner(StorageService.getPartitioner());
if (rtree.partitioner() == null)
rtree.partitioner(StorageService.getPartitioner());
// compare trees, and collect differences
differences.addAll(MerkleTree.difference(ltree, rtree));
// choose a repair method based on the significance of the difference
String format = "Endpoints " + local + " and " + remote + " %s for " + cfname + " on " + range;
if (differences.isEmpty())
{
logger.info(String.format(format, "are consistent"));
completed(remote, cfname);
return;
}
// non-0 difference: perform streaming repair
logger.info(String.format(format, "have " + differences.size() + " range(s) out of sync"));
try
{
performStreamingRepair();
}
catch(IOException e)
{
throw new RuntimeException(e);
}
}
/**
* Starts sending/receiving our list of differences to/from the remote endpoint: creates a callback
* that will be called out of band once the streams complete.
*/
void performStreamingRepair() throws IOException
{
logger.info("Performing streaming repair of " + differences.size() + " ranges with " + remote + " for " + range);
ColumnFamilyStore cfstore = Table.open(tablename).getColumnFamilyStore(cfname);
try
{
Collection<SSTableReader> sstables = cfstore.getSSTables();
Callback callback = new Callback();
// send ranges to the remote node
StreamOutSession outsession = StreamOutSession.create(tablename, remote, callback);
StreamOut.transferSSTables(outsession, sstables, differences, OperationType.AES);
// request ranges from the remote node
StreamIn.requestRanges(remote, tablename, differences, callback, OperationType.AES);
}
catch(Exception e)
{
throw new IOException("Streaming repair failed.", e);
}
}
public String toString()
{
return "#<Differencer " + remote + "/" + range + ">";
}
/**
* When a repair is necessary, this callback is created to wait for the inbound
* and outbound streams to complete.
*/
class Callback extends WrappedRunnable
{
// we expect one callback for the receive, and one for the send
private final AtomicInteger outstanding = new AtomicInteger(2);
protected void runMayThrow() throws Exception
{
if (outstanding.decrementAndGet() > 0)
// waiting on more calls
return;
// all calls finished successfully
completed(remote, cfname);
logger.info(String.format("Finished streaming repair with %s for %s", remote, range));
}
}
}
}
public static class RepairFuture extends FutureTask
{
public final RepairSession session;
RepairFuture(RepairSession session)
{
super(session, null);
this.session = session;
}
}
}