neo4j巨大的图形和解决方案

Question

我在CSV文件中有一个很大的网络.它包含450k节点和45,000,000个关系.正如我在neo4j文档中读到的那样,这种类型的数据库可以处理如此庞大的网络.

我还读到我可以使用嵌入式服务器以及独立服务器.

我的问题是它们之间有什么区别？我想拥有一个保存其数据库状态的服务器.

第二个问题是我可以使用REST API对数据库执行操作,这是一种Java API.

性能有何不同？我希望例如将所有节点级别作为输出.

是否可以从CSV加载图表？

什么是我的问题的最佳解决方案？

Answer 1

下面是您将使用Neo4j-Batch-Inserter导入呼叫记录的代码,而不是动态生成数据,您当然会从文件中读取数据并相应地拆分每条记录.

import org.apache.commons.io.FileUtils;
import org.neo4j.graphdb.RelationshipType;
import org.neo4j.graphdb.index.BatchInserterIndex;
import org.neo4j.helpers.collection.MapUtil;
import org.neo4j.index.impl.lucene.LuceneBatchInserterIndexProvider;
import org.neo4j.kernel.impl.batchinsert.BatchInserterImpl;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Random;

import static org.neo4j.helpers.collection.MapUtil.map;

public class CallRecordImportBatch {

    public static final int MILLION = 1000000;
    public static final int BATCH_SIZE = MILLION;
    public static final int CALLS = 45 * MILLION;
    public static final int USERS = CALLS / 100;
    public static final File STORE_DIR = new File("target/calls_"+ CALLS);
    private static final Random rnd = new Random();

    enum MyRelationshipTypes implements RelationshipType {CALLED}

    private static String randomPhoneNumber() {
        final int phoneNumber = rnd.nextInt(USERS);
        return String.format("%013d", phoneNumber);
    }

    public static void main(String[] args) throws IOException {
        long time = System.currentTimeMillis();
        CallRecordImportBatch importBatch = new CallRecordImportBatch();
        importBatch.createGraphDatabase();
        System.out.println((System.currentTimeMillis() - time) + " ms: "+ "Create Database");
    }

    private BatchInserterImpl db;
    private BatchInserterIndex phoneNumberIndex;

    private void createGraphDatabase() throws IOException {
        if (STORE_DIR.exists()) FileUtils.cleanDirectory(STORE_DIR);
        STORE_DIR.mkdirs();
        db = new BatchInserterImpl(STORE_DIR.getAbsolutePath(),
                MapUtil.stringMap("cache_type", "weak",
                        "neostore.nodestore.db.mapped_memory", "500M",
                        "neostore.relationshipstore.db.mapped_memory", "2000M",
                        "neostore.propertystore.db.mapped_memory", "1000M",
                        "neostore.propertystore.db.strings.mapped_memory", "0M",
                        "neostore.propertystore.db.arrays.mapped_memory", "0M"
                ));
        final LuceneBatchInserterIndexProvider indexProvider = new LuceneBatchInserterIndexProvider(db);
        phoneNumberIndex = indexProvider.nodeIndex("Caller", MapUtil.stringMap("type", "exact"));
        phoneNumberIndex.setCacheCapacity("Caller", 1000000);

        long time = System.currentTimeMillis();
        Map<String,Long> cache = new HashMap<String,Long>(USERS);
        try {
            for (int call=0;call< CALLS;call++) {
                if (call % BATCH_SIZE == 0) {
                    System.out.println((System.currentTimeMillis() - time) + " ms: "+ String.format("calls %d callers %d", call, cache.size()));
                    time = System.currentTimeMillis();
                }
                final String callerNumber = randomPhoneNumber();
                final int duration = (int) (System.currentTimeMillis() % 3600);
                final String calleeNumber = randomPhoneNumber();

                long caller = getOrCreateCaller(cache, callerNumber);
                long callee = getOrCreateCaller(cache, calleeNumber);

                db.createRelationship(caller, callee, MyRelationshipTypes.CALLED, map("duration", duration));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println((System.currentTimeMillis() - time) + " ms: " + String.format("calls %d callers %d", CALLS, cache.size()));
        indexProvider.shutdown();
        db.shutdown();
    }

    private Long getOrCreateCaller(Map<String, Long> cache, String number) {
        final Long callerId = cache.get(number);
        if (callerId!=null) return callerId;
        long caller = createCaller(number);
        cache.put(number, caller);
        return caller;
    }

    private long createCaller(String number) {
        long caller = db.createNode(map("Number", number));
        phoneNumberIndex.add(caller, map("Number", number));
        phoneNumberIndex.flush();
        return caller;
    }
}