[#CONJ-807] Get Access Denied error after 2.5.2 with commit 4e0705bb306a5f7efef222c6886e3a561b13ab60

After apply commit 4e0705bb306a5f7efef222c6886e3a561b13ab60, and run multi-thread program to connect to MySQL server with MariaDB Connector J , it has a high chance to meet with error "Access denied for xx".
Test code as follows:

import java.sql.*;

import java.time.Instant;

import java.util.Properties;

public class TestCache extends Thread {

	// Default no of threads to 10

	private static int NUM_OF_THREADS = 40;

	private static int LOOP = 5;

	private static int pass_conn = 0;

	static int c_nextId = 1;

	private static String url = "jdbc:mysql://server:3306/testj?user=user&password=password";

	int m_myId;

	int pass_conn_i = 0;

	synchronized static int getNextId() {

		return c_nextId++;

	public static void main(String args[]) {

		try {

			// Load the JDBC driver

			Class.forName("org.mariadb.jdbc.Driver");

			System.out.println("Driver loaded");

			// Create the threads

			Thread[] threadList = new Thread[NUM_OF_THREADS];

			double startTime = System.nanoTime();

			// spawn threads

			for (int i = 0; i < NUM_OF_THREADS; i++) {

				threadList[i] = new TestCache();

				threadList[i].start();

			// wait for all threads to end

			for (int i = 0; i < NUM_OF_THREADS; i++) {

				threadList[i].join();

				pass_conn += ((TestCache) threadList[i]).getPassCount();

			double endTime = System.nanoTime();

			double runtime = (endTime - startTime) / 1000000000;

			System.out.printf("Total runtime is %fs \n", runtime);

			System.out.printf("Throughput is : %f \n", pass_conn / runtime);

			System.out.printf("Pass rate is : %f \n", (double) pass_conn / (NUM_OF_THREADS * LOOP));

		} catch (Exception e) {

			e.printStackTrace();

	public TestCache() {

		super();

		// Assign an Id to the thread

		m_myId = getNextId();

	public void run() {

		int i = 0;

		int failureCount = 0;

		for (i = 0; i < LOOP; i++) {

			try {

				Connection conn = null;

				ResultSet rs = null;

				Statement stmt = null;

				Properties info = new Properties();

				info.setProperty("pool", "0");

				// Get the connection

				conn = DriverManager.getConnection(url, info);

				stmt = conn.createStatement(); // Create a Statement

				// Execute the Query

				rs = stmt.executeQuery("select user() as user");

				if (rs.next()) {

					pass_conn_i += 1;

				// Close all the resources

				rs.close();

				rs = null;

				stmt.close();

				stmt = null;

				conn.close();

				conn = null;

				yield(); // Yield To other threads

			} catch (Exception e) {

				System.out.println("Thread " + m_myId + " got Exception: " + e);

				e.printStackTrace();

				failureCount++;

				yield(); // Yield To other threads

		System.out.println("Thread " + m_myId + " is finished. ");

		System.out.println("Failure Count: " + failureCount);

		yield(); // Yield To other threads

	public int getPassCount() {

		return pass_conn_i;

[CONJ-807] Get Access Denied error after 2.5.2 with commit 4e0705bb306a5f7efef222c6886e3a561b13ab60 Created: 2020-07-09 Updated: 2020-11-17 Resolved: 2020-08-24
Status:	Closed
Project:	MariaDB Connector/J
Component/s:	authentication
Affects Version/s:	2.5.2
Fix Version/s:	2.7.0

[CONJ-807] Get Access Denied error after 2.5.2 with commit 4e0705bb306a5f7efef222c6886e3a561b13ab60 Created: 2020-07-09 Updated: 2020-11-17 Resolved: 2020-08-24