Description:
We recently upgraded our JDBC version from 5.1.40 to 8.0.25, and subsequently observed that the off-heap（Direct Memory） memory usage in our container kept increasing until it eventually caused an out-of-memory error and triggered a container restart after about a week. After removing the useCompression=true parameter, we found that the container operated normally. This issue was not observed with the 5.1.40 version.
How to repeat:
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
/**
*
*/
public class JDBCCompressTest {
protected static String driver = "com.mysql.cj.jdbc.Driver";
protected static String url = "jdbc:mysql://localhost:3306/demo?autoReconnect=true&characterEncoding=utf8&useCompression=true";
protected static String user = "root";
protected static String password = "xxxxxx";
public static Connection getConnection() {
try {
Class.forName(driver);
return DriverManager.getConnection(url, user, password);
} catch (ClassNotFoundException e) {
System.out.println("Can't find mysql driver!");
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
public static void main(String[] args) {
int testSize = 63000;
String sql = "select * from events";
System.out.println("testSize = " + testSize);
for(int i=0; i< testSize; i++){
try {
Connection conn = getConnection();
Statement sm = conn.createStatement();
ResultSet rs = sm.executeQuery(sql);
rs.next();
sm.close();
rs.close();
conn.close();
Thread.sleep(1000);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
System.out.println("Done");
//Let it run for a while so I can monitor the java process.
try{ Thread.sleep(60*60*1000); }catch(InterruptedException ex){}
}
}
Description: We recently upgraded our JDBC version from 5.1.40 to 8.0.25, and subsequently observed that the off-heap（Direct Memory） memory usage in our container kept increasing until it eventually caused an out-of-memory error and triggered a container restart after about a week. After removing the useCompression=true parameter, we found that the container operated normally. This issue was not observed with the 5.1.40 version. How to repeat: import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; /** * */ public class JDBCCompressTest { protected static String driver = "com.mysql.cj.jdbc.Driver"; protected static String url = "jdbc:mysql://localhost:3306/demo?autoReconnect=true&characterEncoding=utf8&useCompression=true"; protected static String user = "root"; protected static String password = "xxxxxx"; public static Connection getConnection() { try { Class.forName(driver); return DriverManager.getConnection(url, user, password); } catch (ClassNotFoundException e) { System.out.println("Can't find mysql driver!"); e.printStackTrace(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return null; } public static void main(String[] args) { int testSize = 63000; String sql = "select * from events"; System.out.println("testSize = " + testSize); for(int i=0; i< testSize; i++){ try { Connection conn = getConnection(); Statement sm = conn.createStatement(); ResultSet rs = sm.executeQuery(sql); rs.next(); sm.close(); rs.close(); conn.close(); Thread.sleep(1000); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } System.out.println("Done"); //Let it run for a while so I can monitor the java process. try{ Thread.sleep(60*60*1000); }catch(InterruptedException ex){} } }