Re: ConstraintViolationException on heavy load

[Tudor Rogoz]

Hi,

Seems that the issue still reproduces.
The microkernels may fail on a local non-clustered mongod instance, too (not 
only in cluster).

So what I did, I hope you'll get the exception on your machine too:

- I used the test attached to this email and trigger it 3 times from my IDE.
- the test uses a "database barrier" ( dbWriter.syncMongos(writersNumber, 
"syncOAK") ) and waits for all the java processes before starting to write
- i put a breakpoint on "e.printStackTrace();" just to catch the exception

I was able to reproduce it multiple times with an oak build from Friday (29 
march) on both my Ubuntu station, and on a Windows station (on this platform i 
had to wait longer).
Can you please try again with the attached test, and see if reproduces on your 
station?

Tudor

On 03/27/2013 04:42 PM, Jukka Zitting wrote:

Hi,

On Wed, Mar 27, 2013 at 4:28 PM, Tudor Rogoz <ro...@adobe.com> wrote:

I just made a pull, and is not reproducing on my side, too.It was probably
fixed somehow in the latest commits.

OK, good to know!

BR,

Jukka Zitting

package org.apache.jackrabbit.oak.run;

import java.util.Random;

import javax.jcr.Node;
import javax.jcr.Repository;
import javax.jcr.Session;
import javax.jcr.SimpleCredentials;

import org.apache.jackrabbit.mongomk.impl.MongoConnection;
import org.apache.jackrabbit.mongomk.prototype.MongoMK;
import org.apache.jackrabbit.oak.jcr.Jcr;
import org.junit.Before;
import org.junit.Test;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;

public class ConcurrencyTest {

	Repository repo;
	DBWriter dbWriter;
	String clusterNodeId;
	String database = "dataBase16";
	int writersNumber = 3;

	@Before
	public void before() throws Exception {

		Random randomGenerator = new Random();
		repo = new Jcr(new MongoMK((new MongoConnection("localhost", 27017,
				database)).getDB(), 1)).createRepository();
		clusterNodeId = Integer.toString(randomGenerator.nextInt(1000));
		dbWriter = new DBWriter(clusterNodeId, (new MongoConnection(
				"localhost", 27017, database)).getDB());
	}

	@Test
	public void testException() {
		Session adminSession;
		try {
			adminSession = repo.login(new SimpleCredentials("admin", "admin"
					.toCharArray()));
			dbWriter.initialCommit("syncOAK");
			// wait for all processes
			dbWriter.syncMongos(writersNumber, "syncOAK");
			Node root = adminSession.getRootNode();
			for (int k = 0; k < 10; k++) {
				Node nk = root.addNode("nodeR" + clusterNodeId + k + "R",
						"nt:folder");
				for (int j = 0; j < 50; j++) {
					Node nj = nk.addNode("nodeX" + clusterNodeId + j + "X",
							"nt:folder");
					for (int i = 0; i < 1000; i++) {
						nj.addNode("nodeY" + clusterNodeId + i + "Y",
								"nt:folder");

					}
					adminSession.save();
					System.out.println("ClusterNode:" + clusterNodeId);
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

class DBWriter {

	String clusterNodeId;
	DB database;

	public DBWriter(String clusterNodeId, DB database) {
		this.clusterNodeId = clusterNodeId;
		this.database = database;
	}

	public String initialCommit(String collectionName) {
		BasicDBObject document = new BasicDBObject();
		document.put(clusterNodeId, "1");
		database.getCollection(collectionName).insert(document);
		return clusterNodeId;
	}

	public void syncMongos(int mongosNumber, String collectionName)
			throws InterruptedException {
		while (database.getCollection(collectionName).count() != mongosNumber) {
			Thread.sleep(1000);
		}
	}
}