/*
* Licensed 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 com.facebook.presto.accumulo.metadata;
import com.facebook.presto.accumulo.AccumuloModule;
import com.facebook.presto.accumulo.conf.AccumuloConfig;
import com.facebook.presto.spi.PrestoException;
import com.facebook.presto.spi.SchemaTableName;
import com.facebook.presto.spi.type.Type;
import com.facebook.presto.spi.type.TypeManager;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.collect.ImmutableMap;
import io.airlift.json.ObjectMapperProvider;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.RetryForever;
import org.apache.zookeeper.KeeperException;
import javax.activity.InvalidActivityException;
import javax.inject.Inject;
import java.io.IOException;
import java.util.HashSet;
import java.util.Locale;
import java.util.Set;
import java.util.stream.Collectors;
import static com.facebook.presto.accumulo.AccumuloErrorCode.ZOOKEEPER_ERROR;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
import static org.apache.zookeeper.KeeperException.Code.NONODE;
public class ZooKeeperMetadataManager
{
private static final String DEFAULT_SCHEMA = "default";
private final CuratorFramework curator;
private final ObjectMapper mapper;
@Inject
public ZooKeeperMetadataManager(AccumuloConfig config, TypeManager typeManager)
{
requireNonNull(typeManager, "typeManager is null");
// Create JSON deserializer for the AccumuloTable
ObjectMapperProvider objectMapperProvider = new ObjectMapperProvider();
objectMapperProvider.setJsonDeserializers(ImmutableMap.of(Type.class, new AccumuloModule.TypeDeserializer(typeManager)));
mapper = objectMapperProvider.get();
String zkMetadataRoot = config.getZkMetadataRoot();
String zookeepers = config.getZooKeepers();
// Create the connection to ZooKeeper to check if the metadata root exists
CuratorFramework checkRoot = CuratorFrameworkFactory.newClient(zookeepers, new RetryForever(1000));
checkRoot.start();
try {
// If the metadata root does not exist, create it
if (checkRoot.checkExists().forPath(zkMetadataRoot) == null) {
checkRoot.create().forPath(zkMetadataRoot);
}
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "ZK error checking metadata root", e);
}
checkRoot.close();
// Create the curator client framework to use for metadata management, set at the ZK root
curator = CuratorFrameworkFactory.newClient(zookeepers + zkMetadataRoot, new RetryForever(1000));
curator.start();
try {
// Create default schema should it not exist
if (curator.checkExists().forPath("/" + DEFAULT_SCHEMA) == null) {
curator.create().forPath("/" + DEFAULT_SCHEMA);
}
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "ZK error checking/creating default schema", e);
}
}
public Set<String> getSchemaNames()
{
try {
Set<String> schemas = new HashSet<>();
schemas.addAll(curator.getChildren().forPath("/"));
return schemas;
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "Error fetching schemas", e);
}
}
public Set<String> getTableNames(String schema)
{
String schemaPath = getSchemaPath(schema);
boolean exists;
try {
exists = curator.checkExists().forPath(schemaPath) != null;
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "Error checking if schema exists", e);
}
if (exists) {
try {
Set<String> tables = new HashSet<>();
tables.addAll(
curator.getChildren().forPath(schemaPath)
.stream()
.filter(x -> isAccumuloTable(new SchemaTableName(schema, x)))
.collect(Collectors.toList()));
return tables;
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "Error fetching schemas", e);
}
}
else {
throw new PrestoException(ZOOKEEPER_ERROR, "No metadata for schema" + schema);
}
}
public AccumuloTable getTable(SchemaTableName stName)
{
try {
if (curator.checkExists().forPath(getTablePath(stName)) != null) {
return toAccumuloTable(curator.getData().forPath(getTablePath(stName)));
}
return null;
}
catch (Exception e) {
// Capture race condition between checkExists and getData
if (e instanceof KeeperException && ((KeeperException) e).code() == NONODE) {
return null;
}
throw new PrestoException(ZOOKEEPER_ERROR, "Error fetching table", e);
}
}
public Set<String> getViewNames(String schema)
{
String schemaPath = getSchemaPath(schema);
boolean exists;
try {
exists = curator.checkExists().forPath(schemaPath) != null;
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "Error checking if schema exists", e);
}
if (exists) {
try {
Set<String> tables = new HashSet<>();
tables.addAll(
curator.getChildren().forPath(schemaPath)
.stream()
.filter(x -> isAccumuloView(new SchemaTableName(schema, x)))
.collect(Collectors.toList()));
return tables;
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "Error fetching schemas", e);
}
}
else {
throw new PrestoException(ZOOKEEPER_ERROR, "No metadata for schema " + schema);
}
}
public AccumuloView getView(SchemaTableName stName)
{
try {
String tablePath = getTablePath(stName);
if (curator.checkExists().forPath(tablePath) != null) {
return toAccumuloView(curator.getData().forPath(tablePath));
}
return null;
}
catch (Exception e) {
// Capture race condition between checkExists and getData
if (e instanceof KeeperException && ((KeeperException) e).code() == NONODE) {
return null;
}
throw new PrestoException(ZOOKEEPER_ERROR, "Error fetching view", e);
}
}
public void createTableMetadata(AccumuloTable table)
{
SchemaTableName tableName = table.getSchemaTableName();
String tablePath = getTablePath(tableName);
try {
if (curator.checkExists().forPath(tablePath) != null) {
throw new InvalidActivityException(format("Metadata for table %s already exists", tableName));
}
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "ZK error when checking if table already exists", e);
}
try {
curator.create().creatingParentsIfNeeded().forPath(tablePath, toJsonBytes(table));
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "Error creating table znode in ZooKeeper", e);
}
}
public void deleteTableMetadata(SchemaTableName tableName)
{
try {
curator.delete().deletingChildrenIfNeeded().forPath(getTablePath(tableName));
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "ZK error when deleting table metadata", e);
}
}
public void createViewMetadata(AccumuloView view)
{
SchemaTableName tableName = view.getSchemaTableName();
String viewPath = getTablePath(tableName);
try {
if (curator.checkExists().forPath(viewPath) != null) {
throw new InvalidActivityException(format("Metadata for view %s already exists", tableName));
}
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "ZK error when checking if view already exists", e);
}
try {
curator.create().creatingParentsIfNeeded().forPath(viewPath, toJsonBytes(view));
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "Error creating view znode in ZooKeeper", e);
}
}
public void deleteViewMetadata(SchemaTableName tableName)
{
try {
curator.delete().deletingChildrenIfNeeded().forPath(getTablePath(tableName));
}
catch (Exception e) {
throw new PrestoException(ZOOKEEPER_ERROR, "ZK error when deleting view metadata", e);
}
}
private static String getSchemaPath(String schema)
{
return "/" + schema.toLowerCase(Locale.ENGLISH);
}
private static String getSchemaPath(SchemaTableName tableName)
{
return getSchemaPath(tableName.getSchemaName());
}
private static String getTablePath(SchemaTableName tableName)
{
return getSchemaPath(tableName) + '/' + tableName.getTableName().toLowerCase(Locale.ENGLISH);
}
private boolean isAccumuloTable(SchemaTableName tableName)
{
try {
String path = getTablePath(tableName);
return curator.checkExists().forPath(path) != null && isAccumuloTable(curator.getData().forPath(path));
}
catch (Exception e) {
// Capture race condition between checkExists and getData
if (e instanceof KeeperException && ((KeeperException) e).code() == NONODE) {
return false;
}
throw new PrestoException(ZOOKEEPER_ERROR, "Error checking if path %s is an AccumuloTable object", e);
}
}
private boolean isAccumuloView(SchemaTableName tableName)
{
try {
String path = getTablePath(tableName);
return curator.checkExists().forPath(path) != null && isAccumuloView(curator.getData().forPath(path));
}
catch (Exception e) {
// Capture race condition between checkExists and getData
if (e instanceof KeeperException && ((KeeperException) e).code() == NONODE) {
return false;
}
throw new PrestoException(ZOOKEEPER_ERROR, "Error checking if path is an AccumuloView object", e);
}
}
private boolean isAccumuloTable(byte[] data)
throws IOException
{
// AccumuloTable does not contain a 'data' node
return !mapper.reader().readTree(new String(data)).has("data");
}
private boolean isAccumuloView(byte[] data)
throws IOException
{
// AccumuloView contains a 'data' node
return mapper.reader().readTree(new String(data)).has("data");
}
private AccumuloTable toAccumuloTable(byte[] data)
throws IOException
{
return mapper.readValue(new String(data), AccumuloTable.class);
}
private AccumuloView toAccumuloView(byte[] data)
throws IOException
{
return mapper.readValue(new String(data), AccumuloView.class);
}
private byte[] toJsonBytes(Object obj)
throws IOException
{
return mapper.writeValueAsBytes(obj);
}
}