parallel query perfomance

[nanacoSai]

OrientDB Version: 2.2.32

Java Version: 1.8.0_181

OS: Ubuntu 16.04

Expected behavior

I hope to improve parallel query perfomance.

Actual behavior

I ran a query in one thread when got the results, it cost about 500ms. But in multi-threaded, when I ran the same query in 5 threads at the same time, when got the resutls, all theads cost 2300ms ~ 2600ms; when the number of theads increased to 10, all threads cost 4500ms ~ 5100ms.

Is there some mistakes in my use of OrientDB, or is there some settings can improve parallel query perfomance?

Steps to reproduce

here is my code:

public class TestParallelQuery {
    public static void main(String[] args) {
        try {
            OServerAdmin serverAdmin = new OServerAdmin("remote:localhost").connect("root", "root");
            if (!serverAdmin.existsDatabase("metadata", "plocal")) {
                serverAdmin.createDatabase("metadata", "graph", "plocal");
            }
            serverAdmin.close();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        
        OrientGraphFactory factory= new OrientGraphFactory("remote:localhost/metadata", "root", "root");
        factory.setAutoStartTx(false);
        factory.setupPool(5, 50);;

       int threadCount = 5;
       for (int i = 0; i < threadCount; i++) {
           new Thread(() -> {
               long start = System.currentTimeMillis();
               OrientGraph orientGraph = factory.getTx();
               String sql = "select * from mytable skip 0 limit 100";
               Iterable<Vertex> vertices = orientGraph.command(new OCommandSQL(sql.toString())).execute();
               System.out.println(Thread.currentThread().getName() + "===" + "execute sql cost:" + (System.currentTimeMillis() - start));
           }).start();;
       }
    }
}

[indexzhuo]

Any progress?
Our production environment is facing serious performance issues.

[andrii0lomakin]

Planning to fix in 4.0 by the introduction of snapshot isolation.