org.apache.cassandra.db.DefsTables Maven / Gradle / Ivy
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* distributed with this work for additional information
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* 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.IOException;
import java.nio.ByteBuffer;
import java.util.*;
import com.google.common.collect.Iterables;
import com.google.common.collect.MapDifference;
import com.google.common.collect.Maps;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.cassandra.config.CFMetaData;
import org.apache.cassandra.config.DatabaseDescriptor;
import org.apache.cassandra.config.KSMetaData;
import org.apache.cassandra.config.Schema;
import org.apache.cassandra.db.compaction.CompactionManager;
import org.apache.cassandra.db.filter.QueryFilter;
import org.apache.cassandra.db.marshal.AsciiType;
import org.apache.cassandra.db.marshal.UTF8Type;
import org.apache.cassandra.exceptions.ConfigurationException;
import org.apache.cassandra.service.MigrationManager;
import org.apache.cassandra.service.StorageService;
import org.apache.cassandra.utils.ByteBufferUtil;
/**
* SCHEMA_{KEYSPACES, COLUMNFAMILIES, COLUMNS}_CF are used to store Keyspace/ColumnFamily attributes to make schema
* load/distribution easy, it replaces old mechanism when local migrations where serialized, stored in system.Migrations
* and used for schema distribution.
*
* SCHEMA_KEYSPACES_CF layout:
*
*
* ascii => json_serialized_value
* ...
*
*
* Where is a name of keyspace e.g. "ks".
*
* SCHEMA_COLUMNFAMILIES_CF layout:
*
*
* composite(ascii, ascii) => json_serialized_value
*
*
* Where is a name of keyspace e.g. "ks"., first component of the column name is name of the ColumnFamily, last
* component is the name of the ColumnFamily attribute.
*
* SCHEMA_COLUMNS_CF layout:
*
*
* composite(ascii, ascii, ascii) => json_serialized value
*
*
* Where is a name of keyspace e.g. "ks".
*
* Column names where made composite to support 3-level nesting which represents following structure:
* "ColumnFamily name":"column name":"column attribute" => "value"
*
* Example of schema (using CLI):
*
* schema_keyspaces
* ----------------
* RowKey: ks
* => (column=durable_writes, value=true, timestamp=1327061028312185000)
* => (column=name, value="ks", timestamp=1327061028312185000)
* => (column=replication_factor, value=0, timestamp=1327061028312185000)
* => (column=strategy_class, value="org.apache.cassandra.locator.NetworkTopologyStrategy", timestamp=1327061028312185000)
* => (column=strategy_options, value={"datacenter1":"1"}, timestamp=1327061028312185000)
*
* schema_columnfamilies
* ---------------------
* RowKey: ks
* => (column=cf:bloom_filter_fp_chance, value=0.0, timestamp=1327061105833119000)
* => (column=cf:caching, value="NONE", timestamp=1327061105833119000)
* => (column=cf:column_type, value="Standard", timestamp=1327061105833119000)
* => (column=cf:comment, value="ColumnFamily", timestamp=1327061105833119000)
* => (column=cf:default_validation_class, value="org.apache.cassandra.db.marshal.BytesType", timestamp=1327061105833119000)
* => (column=cf:gc_grace_seconds, value=864000, timestamp=1327061105833119000)
* => (column=cf:id, value=1000, timestamp=1327061105833119000)
* => (column=cf:key_alias, value="S0VZ", timestamp=1327061105833119000)
* ... part of the output omitted.
*
* schema_columns
* --------------
* RowKey: ks
* => (column=cf:c:index_name, value=null, timestamp=1327061105833119000)
* => (column=cf:c:index_options, value=null, timestamp=1327061105833119000)
* => (column=cf:c:index_type, value=null, timestamp=1327061105833119000)
* => (column=cf:c:name, value="aGVsbG8=", timestamp=1327061105833119000)
* => (column=cf:c:validation_class, value="org.apache.cassandra.db.marshal.AsciiType", timestamp=1327061105833119000)
*/
public class DefsTables
{
private static final Logger logger = LoggerFactory.getLogger(DefsTables.class);
/**
* Load keyspace definitions for the system keyspace (system.SCHEMA_KEYSPACES_CF)
*
* @return Collection of found keyspace definitions
*/
public static Collection loadFromKeyspace()
{
List serializedSchema = SystemKeyspace.serializedSchema(SystemKeyspace.SCHEMA_KEYSPACES_CF);
List keyspaces = new ArrayList(serializedSchema.size());
for (Row row : serializedSchema)
{
if (Schema.invalidSchemaRow(row) || Schema.ignoredSchemaRow(row))
continue;
keyspaces.add(KSMetaData.fromSchema(row, serializedColumnFamilies(row.key)));
}
return keyspaces;
}
public static ByteBuffer searchComposite(String name, boolean start)
{
assert name != null;
ByteBuffer nameBytes = UTF8Type.instance.decompose(name);
int length = nameBytes.remaining();
byte[] bytes = new byte[2 + length + 1];
bytes[0] = (byte)((length >> 8) & 0xFF);
bytes[1] = (byte)(length & 0xFF);
ByteBufferUtil.arrayCopy(nameBytes, 0, bytes, 2, length);
bytes[bytes.length - 1] = (byte)(start ? 0 : 1);
return ByteBuffer.wrap(bytes);
}
private static Row serializedColumnFamilies(DecoratedKey ksNameKey)
{
ColumnFamilyStore cfsStore = SystemKeyspace.schemaCFS(SystemKeyspace.SCHEMA_COLUMNFAMILIES_CF);
return new Row(ksNameKey, cfsStore.getColumnFamily(QueryFilter.getIdentityFilter(ksNameKey,
SystemKeyspace.SCHEMA_COLUMNFAMILIES_CF,
System.currentTimeMillis())));
}
/**
* Merge remote schema in form of row mutations with local and mutate ks/cf metadata objects
* (which also involves fs operations on add/drop ks/cf)
*
* @param mutations the schema changes to apply
*
* @throws ConfigurationException If one of metadata attributes has invalid value
* @throws IOException If data was corrupted during transportation or failed to apply fs operations
*/
public static synchronized void mergeSchema(Collection mutations) throws ConfigurationException, IOException
{
// current state of the schema
Map oldKeyspaces = SystemKeyspace.getSchema(SystemKeyspace.SCHEMA_KEYSPACES_CF);
Map oldColumnFamilies = SystemKeyspace.getSchema(SystemKeyspace.SCHEMA_COLUMNFAMILIES_CF);
for (RowMutation mutation : mutations)
mutation.apply();
if (!StorageService.instance.isClientMode())
flushSchemaCFs();
// with new data applied
Map newKeyspaces = SystemKeyspace.getSchema(SystemKeyspace.SCHEMA_KEYSPACES_CF);
Map newColumnFamilies = SystemKeyspace.getSchema(SystemKeyspace.SCHEMA_COLUMNFAMILIES_CF);
Set keyspacesToDrop = mergeKeyspaces(oldKeyspaces, newKeyspaces);
mergeColumnFamilies(oldColumnFamilies, newColumnFamilies);
// it is safe to drop a keyspace only when all nested ColumnFamilies where deleted
for (String keyspaceToDrop : keyspacesToDrop)
dropKeyspace(keyspaceToDrop);
Schema.instance.updateVersionAndAnnounce();
}
private static Set mergeKeyspaces(Map old, Map updated)
{
// calculate the difference between old and new states (note that entriesOnlyLeft() will be always empty)
MapDifference diff = Maps.difference(old, updated);
/**
* At first step we check if any new keyspaces were added.
*/
for (Map.Entry entry : diff.entriesOnlyOnRight().entrySet())
{
ColumnFamily ksAttrs = entry.getValue();
// we don't care about nested ColumnFamilies here because those are going to be processed separately
if (!(ksAttrs.getColumnCount() == 0))
addKeyspace(KSMetaData.fromSchema(new Row(entry.getKey(), entry.getValue()), Collections.emptyList()));
}
/**
* At second step we check if there were any keyspaces re-created, in this context
* re-created means that they were previously deleted but still exist in the low-level schema as empty keys
*/
Map> modifiedEntries = diff.entriesDiffering();
// instead of looping over all modified entries and skipping processed keys all the time
// we would rather store "left to process" items and iterate over them removing already met keys
List leftToProcess = new ArrayList(modifiedEntries.size());
for (Map.Entry> entry : modifiedEntries.entrySet())
{
ColumnFamily prevValue = entry.getValue().leftValue();
ColumnFamily newValue = entry.getValue().rightValue();
if (prevValue.getColumnCount() == 0)
{
addKeyspace(KSMetaData.fromSchema(new Row(entry.getKey(), newValue), Collections.emptyList()));
continue;
}
leftToProcess.add(entry.getKey());
}
if (leftToProcess.size() == 0)
return Collections.emptySet();
/**
* At final step we updating modified keyspaces and saving keyspaces drop them later
*/
Set keyspacesToDrop = new HashSet();
for (DecoratedKey key : leftToProcess)
{
MapDifference.ValueDifference valueDiff = modifiedEntries.get(key);
ColumnFamily newState = valueDiff.rightValue();
if (newState.getColumnCount() == 0)
keyspacesToDrop.add(AsciiType.instance.getString(key.key));
else
updateKeyspace(KSMetaData.fromSchema(new Row(key, newState), Collections.emptyList()));
}
return keyspacesToDrop;
}
private static void mergeColumnFamilies(Map old, Map updated)
{
// calculate the difference between old and new states (note that entriesOnlyLeft() will be always empty)
MapDifference diff = Maps.difference(old, updated);
// check if any new Keyspaces with ColumnFamilies were added.
for (Map.Entry entry : diff.entriesOnlyOnRight().entrySet())
{
ColumnFamily cfAttrs = entry.getValue();
if (!(cfAttrs.getColumnCount() == 0))
{
Map cfDefs = KSMetaData.deserializeColumnFamilies(new Row(entry.getKey(), cfAttrs));
for (CFMetaData cfDef : cfDefs.values())
addColumnFamily(cfDef);
}
}
// deal with modified ColumnFamilies (remember that all of the keyspace nested ColumnFamilies are put to the single row)
Map> modifiedEntries = diff.entriesDiffering();
for (DecoratedKey keyspace : modifiedEntries.keySet())
{
MapDifference.ValueDifference valueDiff = modifiedEntries.get(keyspace);
ColumnFamily prevValue = valueDiff.leftValue(); // state before external modification
ColumnFamily newValue = valueDiff.rightValue(); // updated state
Row newRow = new Row(keyspace, newValue);
if (prevValue.getColumnCount() == 0) // whole keyspace was deleted and now it's re-created
{
for (CFMetaData cfm : KSMetaData.deserializeColumnFamilies(newRow).values())
addColumnFamily(cfm);
}
else if (newValue.getColumnCount() == 0) // whole keyspace is deleted
{
for (CFMetaData cfm : KSMetaData.deserializeColumnFamilies(new Row(keyspace, prevValue)).values())
dropColumnFamily(cfm.ksName, cfm.cfName);
}
else // has modifications in the nested ColumnFamilies, need to perform nested diff to determine what was really changed
{
String ksName = AsciiType.instance.getString(keyspace.key);
Map oldCfDefs = new HashMap();
for (CFMetaData cfm : Schema.instance.getKSMetaData(ksName).cfMetaData().values())
oldCfDefs.put(cfm.cfName, cfm);
Map newCfDefs = KSMetaData.deserializeColumnFamilies(newRow);
MapDifference cfDefDiff = Maps.difference(oldCfDefs, newCfDefs);
for (CFMetaData cfDef : cfDefDiff.entriesOnlyOnRight().values())
addColumnFamily(cfDef);
for (CFMetaData cfDef : cfDefDiff.entriesOnlyOnLeft().values())
dropColumnFamily(cfDef.ksName, cfDef.cfName);
for (MapDifference.ValueDifference cfDef : cfDefDiff.entriesDiffering().values())
updateColumnFamily(cfDef.rightValue());
}
}
}
private static void addKeyspace(KSMetaData ksm)
{
assert Schema.instance.getKSMetaData(ksm.name) == null;
Schema.instance.load(ksm);
if (!StorageService.instance.isClientMode())
{
Keyspace.open(ksm.name);
MigrationManager.instance.notifyCreateKeyspace(ksm);
}
}
private static void addColumnFamily(CFMetaData cfm)
{
assert Schema.instance.getCFMetaData(cfm.ksName, cfm.cfName) == null;
KSMetaData ksm = Schema.instance.getKSMetaData(cfm.ksName);
ksm = KSMetaData.cloneWith(ksm, Iterables.concat(ksm.cfMetaData().values(), Collections.singleton(cfm)));
logger.info("Loading " + cfm);
Schema.instance.load(cfm);
// make sure it's init-ed w/ the old definitions first,
// since we're going to call initCf on the new one manually
Keyspace.open(cfm.ksName);
Schema.instance.setKeyspaceDefinition(ksm);
if (!StorageService.instance.isClientMode())
{
Keyspace.open(ksm.name).initCf(cfm.cfId, cfm.cfName, true);
MigrationManager.instance.notifyCreateColumnFamily(cfm);
}
}
private static void updateKeyspace(KSMetaData newState)
{
KSMetaData oldKsm = Schema.instance.getKSMetaData(newState.name);
assert oldKsm != null;
KSMetaData newKsm = KSMetaData.cloneWith(oldKsm.reloadAttributes(), oldKsm.cfMetaData().values());
Schema.instance.setKeyspaceDefinition(newKsm);
if (!StorageService.instance.isClientMode())
{
Keyspace.open(newState.name).createReplicationStrategy(newKsm);
MigrationManager.instance.notifyUpdateKeyspace(newKsm);
}
}
private static void updateColumnFamily(CFMetaData newState)
{
CFMetaData cfm = Schema.instance.getCFMetaData(newState.ksName, newState.cfName);
assert cfm != null;
cfm.reload();
if (!StorageService.instance.isClientMode())
{
Keyspace keyspace = Keyspace.open(cfm.ksName);
keyspace.getColumnFamilyStore(cfm.cfName).reload();
MigrationManager.instance.notifyUpdateColumnFamily(cfm);
}
}
private static void dropKeyspace(String ksName)
{
KSMetaData ksm = Schema.instance.getKSMetaData(ksName);
String snapshotName = Keyspace.getTimestampedSnapshotName(ksName);
CompactionManager.instance.interruptCompactionFor(ksm.cfMetaData().values(), true);
// remove all cfs from the keyspace instance.
for (CFMetaData cfm : ksm.cfMetaData().values())
{
ColumnFamilyStore cfs = Keyspace.open(ksm.name).getColumnFamilyStore(cfm.cfName);
Schema.instance.purge(cfm);
if (!StorageService.instance.isClientMode())
{
if (DatabaseDescriptor.isAutoSnapshot())
cfs.snapshot(snapshotName);
Keyspace.open(ksm.name).dropCf(cfm.cfId);
}
}
// remove the keyspace from the static instances.
Keyspace.clear(ksm.name);
Schema.instance.clearKeyspaceDefinition(ksm);
if (!StorageService.instance.isClientMode())
{
MigrationManager.instance.notifyDropKeyspace(ksm);
}
}
private static void dropColumnFamily(String ksName, String cfName)
{
KSMetaData ksm = Schema.instance.getKSMetaData(ksName);
assert ksm != null;
ColumnFamilyStore cfs = Keyspace.open(ksName).getColumnFamilyStore(cfName);
assert cfs != null;
// reinitialize the keyspace.
CFMetaData cfm = ksm.cfMetaData().get(cfName);
Schema.instance.purge(cfm);
Schema.instance.setKeyspaceDefinition(makeNewKeyspaceDefinition(ksm, cfm));
CompactionManager.instance.interruptCompactionFor(Arrays.asList(cfm), true);
if (!StorageService.instance.isClientMode())
{
if (DatabaseDescriptor.isAutoSnapshot())
cfs.snapshot(Keyspace.getTimestampedSnapshotName(cfs.name));
Keyspace.open(ksm.name).dropCf(cfm.cfId);
MigrationManager.instance.notifyDropColumnFamily(cfm);
}
}
private static KSMetaData makeNewKeyspaceDefinition(KSMetaData ksm, CFMetaData toExclude)
{
// clone ksm but do not include the new def
List newCfs = new ArrayList(ksm.cfMetaData().values());
newCfs.remove(toExclude);
assert newCfs.size() == ksm.cfMetaData().size() - 1;
return KSMetaData.cloneWith(ksm, newCfs);
}
private static void flushSchemaCFs()
{
SystemKeyspace.forceBlockingFlush(SystemKeyspace.SCHEMA_KEYSPACES_CF);
SystemKeyspace.forceBlockingFlush(SystemKeyspace.SCHEMA_COLUMNFAMILIES_CF);
SystemKeyspace.forceBlockingFlush(SystemKeyspace.SCHEMA_COLUMNS_CF);
SystemKeyspace.forceBlockingFlush(SystemKeyspace.SCHEMA_TRIGGERS_CF);
}
}
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