org.neo4j.kernel.ha.cluster.DefaultMasterImplSPI Maven / Gradle / Ivy

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This component provides the means to set up a cluster of Neo4j instances that act together as a cluster, providing Master-Slave replication and other features.
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/*
 * Copyright (c) 2002-2016 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see .
 */
package org.neo4j.kernel.ha.cluster;

import java.io.File;
import java.io.IOException;

import org.neo4j.com.RequestContext;
import org.neo4j.com.Response;
import org.neo4j.com.storecopy.ResponsePacker;
import org.neo4j.com.storecopy.StoreCopyServer;
import org.neo4j.com.storecopy.StoreWriter;
import org.neo4j.io.fs.FileSystemAbstraction;
import org.neo4j.kernel.internal.GraphDatabaseAPI;
import org.neo4j.kernel.impl.store.id.IdGeneratorFactory;
import org.neo4j.kernel.impl.store.id.IdType;
import org.neo4j.kernel.NeoStoreDataSource;
import org.neo4j.kernel.api.exceptions.TransactionFailureException;
import org.neo4j.kernel.ha.TransactionChecksumLookup;
import org.neo4j.kernel.ha.com.master.MasterImpl;
import org.neo4j.kernel.ha.id.IdAllocation;
import org.neo4j.kernel.impl.api.TransactionCommitProcess;
import org.neo4j.kernel.impl.api.TransactionToApply;
import org.neo4j.kernel.impl.core.LabelTokenHolder;
import org.neo4j.kernel.impl.core.PropertyKeyTokenHolder;
import org.neo4j.kernel.impl.core.RelationshipTypeTokenHolder;
import org.neo4j.kernel.impl.store.StoreId;
import org.neo4j.kernel.impl.store.id.IdGenerator;
import org.neo4j.kernel.impl.transaction.TransactionRepresentation;
import org.neo4j.kernel.impl.transaction.log.LogicalTransactionStore;
import org.neo4j.kernel.impl.transaction.log.TransactionIdStore;
import org.neo4j.kernel.impl.transaction.log.checkpoint.CheckPointer;
import org.neo4j.kernel.impl.transaction.tracing.CommitEvent;
import org.neo4j.kernel.monitoring.Monitors;
import org.neo4j.storageengine.api.TransactionApplicationMode;

public class DefaultMasterImplSPI implements MasterImpl.SPI
{
    private static final int ID_GRAB_SIZE = 1000;
    static final String STORE_COPY_CHECKPOINT_TRIGGER = "store copy";

    private final GraphDatabaseAPI graphDb;
    private final TransactionChecksumLookup txChecksumLookup;
    private final FileSystemAbstraction fileSystem;
    private final LabelTokenHolder labels;
    private final PropertyKeyTokenHolder propertyKeyTokenHolder;
    private final RelationshipTypeTokenHolder relationshipTypeTokenHolder;
    private final IdGeneratorFactory idGeneratorFactory;
    private final NeoStoreDataSource neoStoreDataSource;
    private final File storeDir;
    private final ResponsePacker responsePacker;
    private final Monitors monitors;

    private final TransactionCommitProcess transactionCommitProcess;
    private final CheckPointer checkPointer;

    public DefaultMasterImplSPI( final GraphDatabaseAPI graphDb,
                                 FileSystemAbstraction fileSystemAbstraction,
                                 Monitors monitors,
                                 LabelTokenHolder labels, PropertyKeyTokenHolder propertyKeyTokenHolder,
                                 RelationshipTypeTokenHolder relationshipTypeTokenHolder,
                                 IdGeneratorFactory idGeneratorFactory,
                                 TransactionCommitProcess transactionCommitProcess,
                                 CheckPointer checkPointer,
                                 TransactionIdStore transactionIdStore,
                                 LogicalTransactionStore logicalTransactionStore,
                                 NeoStoreDataSource neoStoreDataSource)
    {
        this.graphDb = graphDb;

        // Hmm, fetching the dependencies here instead of handing them in the constructor directly feels bad,
        // but it seems like there's some intricate usage and need for the db's dependency resolver.
        this.fileSystem = fileSystemAbstraction;
        this.labels = labels;
        this.propertyKeyTokenHolder = propertyKeyTokenHolder;
        this.relationshipTypeTokenHolder = relationshipTypeTokenHolder;
        this.idGeneratorFactory = idGeneratorFactory;
        this.transactionCommitProcess = transactionCommitProcess;
        this.checkPointer = checkPointer;
        this.neoStoreDataSource = neoStoreDataSource;
        this.storeDir = new File( graphDb.getStoreDir() );
        this.txChecksumLookup = new TransactionChecksumLookup( transactionIdStore, logicalTransactionStore );
        this.responsePacker = new ResponsePacker( logicalTransactionStore, transactionIdStore, graphDb::storeId );
        this.monitors = monitors;
    }

    @Override
    public boolean isAccessible()
    {
        // Wait for 5s for the database to become available, if not already so
        return graphDb.isAvailable( 5000 );
    }

    @Override
    public int getOrCreateLabel( String name )
    {
        return labels.getOrCreateId( name );
    }

    @Override
    public int getOrCreateProperty( String name )
    {
        return propertyKeyTokenHolder.getOrCreateId( name );
    }

    @Override
    public IdAllocation allocateIds( IdType idType )
    {
        IdGenerator generator = idGeneratorFactory.get( idType );
        return new IdAllocation( generator.nextIdBatch( ID_GRAB_SIZE ), generator.getHighId(),
                generator.getDefragCount() );
    }

    @Override
    public StoreId storeId()
    {
        return graphDb.storeId();
    }

    @Override
    public long applyPreparedTransaction( TransactionRepresentation preparedTransaction ) throws IOException,
            TransactionFailureException
    {
        return transactionCommitProcess.commit( new TransactionToApply( preparedTransaction ), CommitEvent.NULL,
                TransactionApplicationMode.EXTERNAL );
    }

    @Override
    public Integer createRelationshipType( String name )
    {
        return relationshipTypeTokenHolder.getOrCreateId( name );
    }

    @Override
    public long getTransactionChecksum( long txId ) throws IOException
    {
        return txChecksumLookup.applyAsLong( txId );
    }

    @Override
    public RequestContext flushStoresAndStreamStoreFiles( StoreWriter writer )
    {
        StoreCopyServer streamer = new StoreCopyServer( neoStoreDataSource,
                checkPointer, fileSystem, storeDir, monitors.newMonitor( StoreCopyServer.Monitor.class ) );
        return streamer.flushStoresAndStreamStoreFiles( STORE_COPY_CHECKPOINT_TRIGGER, writer, false );
    }

    @Override
    public  Response packTransactionStreamResponse( RequestContext context, T response )
    {
        return responsePacker.packTransactionStreamResponse( context, response );
    }

    @Override
    public  Response packTransactionObligationResponse( RequestContext context, T response )
    {
        return responsePacker.packTransactionObligationResponse( context, response );
    }

    @Override
    public  Response packEmptyResponse( T response )
    {
        return responsePacker.packEmptyResponse( response );
    }
}