Irregular errors in driver when multiple statements from one connection used concurrently #115
Comments
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The same issue here. It looks like driver not longer sync on connection and concurrent calls of any SQL query execution breaks native protocol. |
Thanks for the heads up, I ran this with a driver version before 2.1.0.10 and it fixed my issue. Obviously not ideal but it got me what I needed. |
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After some investigation I realized that multithreading was broken exactly in 2.1.0.9, after serverless Redshift support was added. Here is the snippet which reproduces the problem. import com.amazon.redshift.jdbc42.Driver;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;
public class RedshiftTestMT {
public static void main(String[] args) throws Exception {
System.out.println("Test MT");
Driver rdrv = new Driver();
Properties props = new Properties();
props.put("AccessKeyID", "<access-key>");
props.put("SecretAccessKey", "<secret-key>");
props.put("DbUser", "awsuser");
try (Connection connection = rdrv.connect("jdbc:redshift:iam://<server-addr>:5439/dev", props);) {
System.out.println("Run tests");
List<Thread> startedThreads = new ArrayList<>();
for (int i = 0; i < 20; i++) {
int finalI = i;
Thread thread = new Thread("Thread " + finalI) {
@Override
public void run() {
try {
runSimpleQuery(connection, finalI);
} catch (SQLException e) {
e.printStackTrace();
}
}
};
startedThreads.add(thread);
thread.start();
}
for (Thread thread : startedThreads) {
thread.join();
}
}
System.out.println("Finished");
}
private static void runSimpleQuery(Connection connection, int index) throws SQLException {
System.out.println("Run for thread " + index);
try (PreparedStatement stat = connection.prepareStatement("SELECT 'hello world!'")) {
try (ResultSet results = stat.executeQuery()) {
while (results.next()) {
System.out.println(results.getString(1));
}
}
}
System.out.println("\tFinished for thread " + index);
}
}Probably it is somehow related to serverless Redshift support.. |
Driver version
2.1.0.26
Redshift version
PostgreSQL 8.0.2 on i686-pc-linux-gnu, compiled by GCC gcc (GCC) 3.4.2 20041017 (Red Hat 3.4.2-6.fc3), Redshift 1.0.63269
Client Operating System
macOS Version 14.3.1
JAVA/JVM version
17.0.3
Problem description
Expected: no errors
Actual: one of the statements fails due to
Unexpected packet typeerrorJDBC trace logs
Reproduction code
This code demonstrates the problem, but it may not always occur due to timing variations.
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