Question

我想用多个线程将大量数据加载到Orient DB中。我正在使用OrientDB 2.2.20和Java 1.8.0_131在示例测试客户端下运行。但是当我使用5个线程和10000个样本运行此客户端时，客户端的CPU使用率超过100％并且该过程几乎已经死亡。

实际上我想使用图形API在它们之间创建大量的顶点和边缘。但我在一些帖子中读到，对于大量插入使用文档API并设置in＆amp;指出使用doc API的指针。因此尝试了这个程序。

有人能指出代码中的错误吗？

public OrientDBTestClient(){

    db = new ODatabaseDocumentTx(url).open(userName, password);
}

public static void main(String[] args) throws Exception{

    int threadCnt = Integer.parseInt(args[0]);
    OrientDBTestClient client = new OrientDBTestClient();

    try {

        db.declareIntent(new OIntentMassiveInsert());

        Thread[] threads = new Thread[threadCnt];
        for (int i = 0; i < threadCnt; i++) {
            Thread loadStatsThread = new Thread(client.new LoadTask(Integer.parseInt(args[1])));
            loadStatsThread.setName("LoadTask" + (i + 1));
            loadStatsThread.start();
            threads[i] = loadStatsThread;
        }
    }
    catch(Exception e){
        e.printStackTrace();
    }
}

private class LoadTask implements Runnable{

    public int count = 0;

    public LoadTask(int count){
        this.count = count;
    }

    public void run(){
        long start = System.currentTimeMillis();
        try{
            db.activateOnCurrentThread();
            for(int i = 0; i < count; ++ i){
                storeStatsInDB(i +"");
            }
        }
        catch(Exception e){
            log.println("Error in LoadTask : " + e.getMessage());
            e.printStackTrace();
        }
        finally {
            db.commit();
            System.out.println(Thread.currentThread().getName() + " loaded: " + count + " services in: "  + (System.currentTimeMillis() - start) + "ms");
        }
    }
}

public void storeStatsInDB(String id) throws Exception{

    try{
        long start = System.currentTimeMillis();

        ODocument doc = db.newInstance();
        doc.reset();
        doc.setClassName("ServiceStatistics");

        doc.field("serviceID", id);
        doc.field("name", "Service=" + id);

        doc.save();
    }
    catch(Exception e){
        log.println("Exception :" + e.getMessage());
        e.printStackTrace();
    }

}

Answer 1

db实例在线程之间不可共享。你有两个选择：

为每个帖子创建一个实例
使用游泳池（我的第一选择）：http://orientdb.com/docs/last/Java-Multi-Threading.html#working-with-databases

以下示例摘自内部测试：

pool = new OPartitionedDatabasePool("remote:localshot/test", "admin", "admin");
Runnable acquirer = () -> {

  ODatabaseDocumentTx db = pool.acquire();

  try {

    List<ODocument> res = db.query(new OSQLSynchQuery<>("SELECT * FROM OUser"));


  } finally {

    db.close();
  }

};

//spawn 20 threads
List<CompletableFuture<Void>> futures = IntStream.range(0, 19).boxed().map(i -> CompletableFuture.runAsync(acquirer))
    .collect(Collectors.toList());

futures.forEach(cf -> cf.join());`

OrientDB客户端CPU的ODB2.2.20超过100％

1 个答案: