Multithreading procedure calls

Main.java

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.*;

public class Main {
    static MysqlDataSource mysqlDataSource = new MysqlDataSource();
    static ExecutorService executor = Executors.newFixedThreadPool(30);


    public static void main(String[] args) throws SQLException, InterruptedException {
        mysqlDataSource.setServerName("127.0.0.1");
        mysqlDataSource.setDatabaseName("my_db");
        mysqlDataSource.setUser("root");
        mysqlDataSource.setPassword("root");
        Connection c = mysqlDataSource.getConnection();

        ResultSet rs = c.createStatement().executeQuery("select task_id from task order by task_id desc");

        Queue<Long> taskIds = new LinkedList<>();

        while (rs.next()) {
            taskIds.add(rs.getLong("task_id"));
        }

        BlockingQueue<TaskInfo> taskInfos = new LinkedBlockingQueue<>();

        taskIds.stream().map(Main::getFutureTaskInfo).forEach(f -> f.thenAccept(taskInfos::add));

        executor.shutdown();

        TaskInfo taskInfo;

        while(true) {
            taskInfo = taskInfos.poll(10, TimeUnit.SECONDS);

            if (taskInfo == null) System.exit(0);

            if (taskInfo.exception != null) {
                System.err.println(taskInfo);
            } else {
                System.out.println(taskInfo);
            }
        }
    }


    public static CompletableFuture<TaskInfo> getFutureTaskInfo(Long taskId) {
        return CompletableFuture.supplyAsync(() -> {
            TaskInfo ti = new TaskInfo();
            ti.taskId = taskId;

            try {
                Connection con = mysqlDataSource.getConnection();
                CallableStatement callableStatement = con.prepareCall("CALL myProcedure(?)");
                callableStatement.setLong(1, taskId);
                ResultSet percRS = callableStatement.executeQuery();
                percRS.first();
                ti.percentage =  percRS.getInt(1);
                con.close();
            } catch (SQLException e) {
                ti.exception = e;
            }
            return ti;
        }, executor);
    }

    static class TaskInfo {
        long taskId;
        int percentage;
        Exception exception;

        @Override
        public String toString() {
            return String.format("TaskInfo{taskId=%d, percentage=%d, exception=%s}", taskId, percentage, exception);
        }
    }
}