/*
* 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.db;
import java.io.File;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.Future;
import java.util.concurrent.locks.ReentrantReadWriteLock;
import com.google.common.base.Function;
import com.google.common.collect.Iterables;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.config.*;
import org.apache.cassandra.db.commitlog.CommitLog;
import org.apache.cassandra.db.filter.QueryFilter;
import org.apache.cassandra.db.index.SecondaryIndex;
import org.apache.cassandra.db.index.SecondaryIndexManager;
import org.apache.cassandra.io.sstable.SSTableReader;
import org.apache.cassandra.locator.AbstractReplicationStrategy;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.service.pager.QueryPagers;
import org.apache.cassandra.tracing.Tracing;
import org.apache.cassandra.metrics.KeyspaceMetrics;
/**
* It represents a Keyspace.
*/
public class Keyspace
{
public static final String SYSTEM_KS = "system";
private static final int DEFAULT_PAGE_SIZE = 10000;
private static final Logger logger = LoggerFactory.getLogger(Keyspace.class);
/**
* accesses to CFS.memtable should acquire this for thread safety.
* CFS.maybeSwitchMemtable should aquire the writeLock; see that method for the full explanation.
* <p/>
* (Enabling fairness in the RRWL is observed to decrease throughput, so we leave it off.)
*/
public static final ReentrantReadWriteLock switchLock = new ReentrantReadWriteLock();
public final KeyspaceMetrics metric;
// It is possible to call Keyspace.open without a running daemon, so it makes sense to ensure
// proper directories here as well as in CassandraDaemon.
static
{
if (!(Config.isClientMode() || StorageService.instance.isClientMode()))
DatabaseDescriptor.createAllDirectories();
}
public final KSMetaData metadata;
/* ColumnFamilyStore per column family */
private final ConcurrentMap<UUID, ColumnFamilyStore> columnFamilyStores = new ConcurrentHashMap<UUID, ColumnFamilyStore>();
private volatile AbstractReplicationStrategy replicationStrategy;
public static final Function<String,Keyspace> keyspaceTransformer = new Function<String, Keyspace>()
{
public Keyspace apply(String keyspaceName)
{
return Keyspace.open(keyspaceName);
}
};
public static Keyspace open(String keyspaceName)
{
return open(keyspaceName, Schema.instance, true);
}
public static Keyspace openWithoutSSTables(String keyspaceName)
{
return open(keyspaceName, Schema.instance, false);
}
private static Keyspace open(String keyspaceName, Schema schema, boolean loadSSTables)
{
Keyspace keyspaceInstance = schema.getKeyspaceInstance(keyspaceName);
if (keyspaceInstance == null)
{
// instantiate the Keyspace. we could use putIfAbsent but it's important to making sure it is only done once
// per keyspace, so we synchronize and re-check before doing it.
synchronized (Keyspace.class)
{
keyspaceInstance = schema.getKeyspaceInstance(keyspaceName);
if (keyspaceInstance == null)
{
// open and store the keyspace
keyspaceInstance = new Keyspace(keyspaceName, loadSSTables);
schema.storeKeyspaceInstance(keyspaceInstance);
// keyspace has to be constructed and in the cache before cacheRow can be called
for (ColumnFamilyStore cfs : keyspaceInstance.getColumnFamilyStores())
cfs.initRowCache();
}
}
}
return keyspaceInstance;
}
public static Keyspace clear(String keyspaceName)
{
return clear(keyspaceName, Schema.instance);
}
public static Keyspace clear(String keyspaceName, Schema schema)
{
synchronized (Keyspace.class)
{
Keyspace t = schema.removeKeyspaceInstance(keyspaceName);
if (t != null)
{
for (ColumnFamilyStore cfs : t.getColumnFamilyStores())
t.unloadCf(cfs);
t.metric.release();
}
return t;
}
}
/**
* Removes every SSTable in the directory from the appropriate DataTracker's view.
* @param directory the unreadable directory, possibly with SSTables in it, but not necessarily.
*/
public static void removeUnreadableSSTables(File directory)
{
for (Keyspace keyspace : Keyspace.all())
{
for (ColumnFamilyStore baseCfs : keyspace.getColumnFamilyStores())
{
for (ColumnFamilyStore cfs : baseCfs.concatWithIndexes())
cfs.maybeRemoveUnreadableSSTables(directory);
}
}
}
public Collection<ColumnFamilyStore> getColumnFamilyStores()
{
return Collections.unmodifiableCollection(columnFamilyStores.values());
}
public ColumnFamilyStore getColumnFamilyStore(String cfName)
{
UUID id = Schema.instance.getId(getName(), cfName);
if (id == null)
throw new IllegalArgumentException(String.format("Unknown keyspace/cf pair (%s.%s)", getName(), cfName));
return getColumnFamilyStore(id);
}
public ColumnFamilyStore getColumnFamilyStore(UUID id)
{
ColumnFamilyStore cfs = columnFamilyStores.get(id);
if (cfs == null)
throw new IllegalArgumentException("Unknown CF " + id);
return cfs;
}
/**
* Take a snapshot of the specific column family, or the entire set of column families
* if columnFamily is null with a given timestamp
*
* @param snapshotName the tag associated with the name of the snapshot. This value may not be null
* @param columnFamilyName the column family to snapshot or all on null
* @throws IOException if the column family doesn't exist
*/
public void snapshot(String snapshotName, String columnFamilyName) throws IOException
{
assert snapshotName != null;
boolean tookSnapShot = false;
for (ColumnFamilyStore cfStore : columnFamilyStores.values())
{
if (columnFamilyName == null || cfStore.name.equals(columnFamilyName))
{
tookSnapShot = true;
cfStore.snapshot(snapshotName);
}
}
if ((columnFamilyName != null) && !tookSnapShot)
throw new IOException("Failed taking snapshot. Column family " + columnFamilyName + " does not exist.");
}
/**
* @param clientSuppliedName may be null.
* @return the name of the snapshot
*/
public static String getTimestampedSnapshotName(String clientSuppliedName)
{
String snapshotName = Long.toString(System.currentTimeMillis());
if (clientSuppliedName != null && !clientSuppliedName.equals(""))
{
snapshotName = snapshotName + "-" + clientSuppliedName;
}
return snapshotName;
}
/**
* Check whether snapshots already exists for a given name.
*
* @param snapshotName the user supplied snapshot name
* @return true if the snapshot exists
*/
public boolean snapshotExists(String snapshotName)
{
assert snapshotName != null;
for (ColumnFamilyStore cfStore : columnFamilyStores.values())
{
if (cfStore.snapshotExists(snapshotName))
return true;
}
return false;
}
/**
* Clear all the snapshots for a given keyspace.
*
* @param snapshotName the user supplied snapshot name. It empty or null,
* all the snapshots will be cleaned
*/
public static void clearSnapshot(String snapshotName, String keyspace)
{
List<File> snapshotDirs = Directories.getKSChildDirectories(keyspace);
Directories.clearSnapshot(snapshotName, snapshotDirs);
}
/**
* @return A list of open SSTableReaders
*/
public List<SSTableReader> getAllSSTables()
{
List<SSTableReader> list = new ArrayList<SSTableReader>(columnFamilyStores.size());
for (ColumnFamilyStore cfStore : columnFamilyStores.values())
list.addAll(cfStore.getSSTables());
return list;
}
private Keyspace(String keyspaceName, boolean loadSSTables)
{
metadata = Schema.instance.getKSMetaData(keyspaceName);
assert metadata != null : "Unknown keyspace " + keyspaceName;
createReplicationStrategy(metadata);
this.metric = new KeyspaceMetrics(this);
for (CFMetaData cfm : new ArrayList<CFMetaData>(metadata.cfMetaData().values()))
{
logger.debug("Initializing {}.{}", getName(), cfm.cfName);
initCf(cfm.cfId, cfm.cfName, loadSSTables);
}
}
public void createReplicationStrategy(KSMetaData ksm)
{
replicationStrategy = AbstractReplicationStrategy.createReplicationStrategy(ksm.name,
ksm.strategyClass,
StorageService.instance.getTokenMetadata(),
DatabaseDescriptor.getEndpointSnitch(),
ksm.strategyOptions);
}
// best invoked on the compaction mananger.
public void dropCf(UUID cfId)
{
assert columnFamilyStores.containsKey(cfId);
ColumnFamilyStore cfs = columnFamilyStores.remove(cfId);
if (cfs == null)
return;
unloadCf(cfs);
}
// disassociate a cfs from this keyspace instance.
private void unloadCf(ColumnFamilyStore cfs)
{
cfs.forceBlockingFlush();
cfs.invalidate();
}
/**
* adds a cf to internal structures, ends up creating disk files).
*/
public void initCf(UUID cfId, String cfName, boolean loadSSTables)
{
ColumnFamilyStore cfs = columnFamilyStores.get(cfId);
if (cfs == null)
{
// CFS being created for the first time, either on server startup or new CF being added.
// We don't worry about races here; startup is safe, and adding multiple idential CFs
// simultaneously is a "don't do that" scenario.
ColumnFamilyStore oldCfs = columnFamilyStores.putIfAbsent(cfId, ColumnFamilyStore.createColumnFamilyStore(this, cfName, loadSSTables));
// CFS mbean instantiation will error out before we hit this, but in case that changes...
if (oldCfs != null)
throw new IllegalStateException("added multiple mappings for cf id " + cfId);
}
else
{
// re-initializing an existing CF. This will happen if you cleared the schema
// on this node and it's getting repopulated from the rest of the cluster.
assert cfs.name.equals(cfName);
cfs.metadata.reload();
cfs.reload();
}
}
public Row getRow(QueryFilter filter)
{
ColumnFamilyStore cfStore = getColumnFamilyStore(filter.getColumnFamilyName());
ColumnFamily columnFamily = cfStore.getColumnFamily(filter);
return new Row(filter.key, columnFamily);
}
public void apply(RowMutation mutation, boolean writeCommitLog)
{
apply(mutation, writeCommitLog, true);
}
/**
* This method appends a row to the global CommitLog, then updates memtables and indexes.
*
* @param mutation the row to write. Must not be modified after calling apply, since commitlog append
* may happen concurrently, depending on the CL Executor type.
* @param writeCommitLog false to disable commitlog append entirely
* @param updateIndexes false to disable index updates (used by CollationController "defragmenting")
*/
public void apply(RowMutation mutation, boolean writeCommitLog, boolean updateIndexes)
{
// write the mutation to the commitlog and memtables
Tracing.trace("Acquiring switchLock read lock");
switchLock.readLock().lock();
try
{
if (writeCommitLog)
{
Tracing.trace("Appending to commitlog");
CommitLog.instance.add(mutation);
}
DecoratedKey key = StorageService.getPartitioner().decorateKey(mutation.key());
for (ColumnFamily cf : mutation.getColumnFamilies())
{
ColumnFamilyStore cfs = columnFamilyStores.get(cf.id());
if (cfs == null)
{
logger.error("Attempting to mutate non-existant column family " + cf.id());
continue;
}
Tracing.trace("Adding to {} memtable", cf.metadata().cfName);
cfs.apply(key, cf, updateIndexes ? cfs.indexManager.updaterFor(key, cf) : SecondaryIndexManager.nullUpdater);
}
}
finally
{
switchLock.readLock().unlock();
}
}
public AbstractReplicationStrategy getReplicationStrategy()
{
return replicationStrategy;
}
/**
* @param key row to index
* @param cfs ColumnFamily to index row in
* @param idxNames columns to index, in comparator order
*/
public static void indexRow(DecoratedKey key, ColumnFamilyStore cfs, Set<String> idxNames)
{
if (logger.isDebugEnabled())
logger.debug("Indexing row {} ", cfs.metadata.getKeyValidator().getString(key.key));
Set<SecondaryIndex> indexes = cfs.indexManager.getIndexesByNames(idxNames);
switchLock.readLock().lock();
try
{
Iterator<ColumnFamily> pager = QueryPagers.pageRowLocally(cfs, key.key, DEFAULT_PAGE_SIZE);
while (pager.hasNext())
{
ColumnFamily cf = pager.next();
ColumnFamily cf2 = cf.cloneMeShallow();
for (Column column : cf)
{
if (cfs.indexManager.indexes(column.name(), indexes))
cf2.addColumn(column);
}
cfs.indexManager.indexRow(key.key, cf2);
}
}
finally
{
switchLock.readLock().unlock();
}
}
public List<Future<?>> flush()
{
List<Future<?>> futures = new ArrayList<Future<?>>(columnFamilyStores.size());
for (UUID cfId : columnFamilyStores.keySet())
futures.add(columnFamilyStores.get(cfId).forceFlush());
return futures;
}
public static Iterable<Keyspace> all()
{
return Iterables.transform(Schema.instance.getKeyspaces(), keyspaceTransformer);
}
public static Iterable<Keyspace> nonSystem()
{
return Iterables.transform(Schema.instance.getNonSystemKeyspaces(), keyspaceTransformer);
}
public static Iterable<Keyspace> system()
{
return Iterables.transform(Schema.systemKeyspaceNames, keyspaceTransformer);
}
@Override
public String toString()
{
return getClass().getSimpleName() + "(name='" + getName() + "')";
}
public String getName()
{
return metadata.name;
}
}