Thread

1. Memory leak in 7.0.3 JDBC driver

   Steve Sullivan <sullivan@mathcom.com> — 2001-06-17T17:59:21Z

   Hi,
   
   I'm running Postgresql 7.0.3 on Redhat 7.1 on a Pentium.
   When I use Connection.getCatalog() and similar calls,
   the amount of free memory slowly decreases.  I get:
   
   after get catalog: 0:  totmem: 2031616 freemem: 1899480
   after get catalog: 100:  totmem: 2031616 freemem: 1854576
   after get catalog: 200:  totmem: 2031616 freemem: 1810008
   after get catalog: 300:  totmem: 2031616 freemem: 1765104
   after get catalog: 400:  totmem: 2031616 freemem: 1720200
   after get catalog: 500:  totmem: 2031616 freemem: 1675296
   after get catalog: 600:  totmem: 2031616 freemem: 1630808
   after get catalog: 700:  totmem: 2031616 freemem: 1585904
   after get catalog: 800:  totmem: 2031616 freemem: 1541000
   after get catalog: 900:  totmem: 2031616 freemem: 1496096
   
   It's losing about 448 bytes per iteration.
   The Java test program I wrote is appended.  I invoked it using:
   
   java Tbtestc org.postgresql.Driver jdbc:postgresql:mydb myuser mypswd testtablea > loga
   
   If you need any further info, please contact me.
   Thanks,
   
   Steve
   
   ========================================
   Steve Sullivan    sullivan@mathcom.com
   
      Mathcom Solutions, Inc.
       * Java, XML, and web oriented development.
       * Language development and translation.
       * Optimization, simulation, and mathematical modeling.
   
   http://www.mathcom.com    303-494-7115
   ========================================
   
   
   
   ========== begin Tbtestc.java ==========
   
   import java.io.PrintWriter;
   import java.sql.Connection;
   import java.sql.DatabaseMetaData;
   import java.sql.DriverManager;
   import java.sql.PreparedStatement;
   import java.sql.ResultSet;
   import java.sql.ResultSetMetaData;
   import java.sql.SQLException;
   import java.sql.Statement;
   import java.sql.Types;
   
   /**
    * Tests simple jdbc access for memory leaks.
    */
   
   
   public class Tbtestc {
   	public static void main( String[] args) {
   		new Tbtestc( args);
   	}
   
   	void prtln( String msg) {
   		System.out.println( msg);
   	}
   
   	void badparms( String msg)
   	{
   		prtln("");
   		prtln("Testc: Error: " + msg);
   		prtln("args:  drivername url userid pswd tabname (will be deleted)");
   		System.exit(1);
   	}
   
   
   	public Tbtestc( String[] args) {
   		int ii;
   
   		if (args.length != 5) badparms("wrong num parms");
   		String drivername	= args[0];
   		String url			= args[1];
   		String userid		= args[2];
   		String pswd			= args[3];
   		String tabname		= args[4];
   
   	    // Connect to database and run the tests
   		try {
   			testit( drivername, url, userid, pswd, tabname);
   		}
   		catch( Exception exc) {
   			prtln("Tbtestc: error: " + exc);
   			exc.printStackTrace();
   		}
   	}
   
   
   	void testit(
   		String drivername,
   		String url,
   		String userid,
   		String pswd,
   		String tabname)
   	throws SQLException, ClassNotFoundException
   	{
   		int iterlim = 1000;
   		int iterdelta = 100;
   		int ii, jj, kk;
   		int ncols;
   		String tstg;
   		ResultSet rs = null;
   		int maxcolwidth = 30;
   
   	    Connection dbcon = null;
   		Statement dbst = null;
   
   	    // Load the driver
   		Class.forName( drivername);
   
       	prtln("Connecting to Database URL = " + url);
   		dbcon = DriverManager.getConnection( url, userid, pswd);
   		prtln("got dbcon.");
   		dbst = dbcon.createStatement();
   		prtln("got dbst.");
   
   		try { dbst.executeUpdate("drop table " + tabname); }
   		catch( SQLException sqe) {
   			prtln("could not drop table " + tabname + ": " + sqe);
   		}
   
   		dbst.executeUpdate("create table " + tabname
   			+ " (colstg varchar(22) not null,"
   			+ " colint integer not null,"
   			+ " primary key (colstg, colint))");
   		prtln("testit: created " + tabname);
   
   		prtfreemem("before get catalog");
   		String catalog = null;
   		int isol = 0;
   		boolean readonly = false;
   		boolean autocommit = false;
   		for (kk = 0; kk < iterlim; kk++) {
   			catalog = dbcon.getCatalog();
   			isol = dbcon.getTransactionIsolation();
   			readonly = dbcon.isReadOnly();
   			autocommit = dbcon.getAutoCommit();
   			if (kk % iterdelta == 0) prtfreemem("after get catalog: " + kk);
   		}
   		prtfreemem("after get catalog");
   		prtln("    catalog: " + catalog);
   		prtln("    transaction isolation level: " + isol);
   		prtln("    read only: " + readonly);
   		prtln("    auto commit: " + autocommit);
   
   		DatabaseMetaData dbm = null;
   		for (kk = 0; kk < iterlim; kk++) {
   			dbm = dbcon.getMetaData();
   			if (kk % iterdelta == 0) prtfreemem("after get dbm: " + kk);
   		}
   		prtfreemem("after get dbm");
   		String prodname = null;
   		String version = null;
   		String geturl = null;
   		String getuser = null;
   		for (kk = 0; kk < iterlim; kk++) {
   			prodname = dbm.getDatabaseProductName();
   			version = dbm.getDatabaseProductVersion();
   			geturl = dbm.getURL();
   			getuser = dbm.getUserName();
   			if (kk % iterdelta == 0) prtfreemem("after get prodname: " + kk);
   		}
   		prtfreemem("after get prodname");
   		prtln("database meta data:");
   		prtln("    product name: " + prodname);
   		prtln("    version: " + version);
   		prtln("    URL: " + geturl);
   		prtln("    user: " + getuser);
   
   		for (kk = 0; kk < iterlim; kk++) {
   			ResultSet keyrs = dbm.getPrimaryKeys(
   				null, null,			// catalog, schema
   				tabname);
   			keyrs.close();
   			if (kk % iterdelta == 0) prtfreemem("after get keys: " + kk);
   		}
   		prtfreemem("after get keys");
   
   	}
   
   
   
   	void prtfreemem( String msgparm) {
   		Runtime runtime = Runtime.getRuntime();
   		runtime.gc();
   		long totmem = runtime.totalMemory();
   		long freemem = runtime.freeMemory();
   		String msg = msgparm + ": "
   			+ " totmem: " + totmem
   			+ " freemem: " + freemem;
   		System.out.println( msg);
   	}
   
   
   } // end class Tbtestc
   
   
   ========== end Tbtestc.java ==========
   
   

2. RE: Memory leak in 7.0.3 JDBC driver

   Rainer Mager <rmager@vgkk.com> — 2001-06-20T23:21:32Z

   I posted yesterday regarding a memory leak I found in the JDBC driver in
   7.1. I didn't check but it is quite likely it also existed in 7.0. The patch
   I created hasn't been checked by anyone else yet so I don't know if it helps
   for others or not. Feel free to try it.
   
   --Rainer
   
   
   > -----Original Message-----
   > From: pgsql-bugs-owner@postgresql.org
   > [mailto:pgsql-bugs-owner@postgresql.org]On Behalf Of Steve Sullivan
   > Sent: Monday, June 18, 2001 2:59 AM
   > To: pgsql-bugs@postgresql.org
   > Subject: [BUGS] Memory leak in 7.0.3 JDBC driver
   >
   >
   >
   > Hi,
   >
   > I'm running Postgresql 7.0.3 on Redhat 7.1 on a Pentium.
   > When I use Connection.getCatalog() and similar calls,
   > the amount of free memory slowly decreases.  I get:
   >
   > after get catalog: 0:  totmem: 2031616 freemem: 1899480
   > after get catalog: 100:  totmem: 2031616 freemem: 1854576
   > after get catalog: 200:  totmem: 2031616 freemem: 1810008
   > after get catalog: 300:  totmem: 2031616 freemem: 1765104
   > after get catalog: 400:  totmem: 2031616 freemem: 1720200
   > after get catalog: 500:  totmem: 2031616 freemem: 1675296
   > after get catalog: 600:  totmem: 2031616 freemem: 1630808
   > after get catalog: 700:  totmem: 2031616 freemem: 1585904
   > after get catalog: 800:  totmem: 2031616 freemem: 1541000
   > after get catalog: 900:  totmem: 2031616 freemem: 1496096
   >
   > It's losing about 448 bytes per iteration.
   > The Java test program I wrote is appended.  I invoked it using:
   >
   > java Tbtestc org.postgresql.Driver jdbc:postgresql:mydb myuser
   > mypswd testtablea > loga
   >
   > If you need any further info, please contact me.
   > Thanks,
   >
   > Steve
   >
   > ========================================
   > Steve Sullivan    sullivan@mathcom.com
   >
   >    Mathcom Solutions, Inc.
   >     * Java, XML, and web oriented development.
   >     * Language development and translation.
   >     * Optimization, simulation, and mathematical modeling.
   >
   > http://www.mathcom.com    303-494-7115
   > ========================================
   >
   >
   >
   > ========== begin Tbtestc.java ==========
   >
   > import java.io.PrintWriter;
   > import java.sql.Connection;
   > import java.sql.DatabaseMetaData;
   > import java.sql.DriverManager;
   > import java.sql.PreparedStatement;
   > import java.sql.ResultSet;
   > import java.sql.ResultSetMetaData;
   > import java.sql.SQLException;
   > import java.sql.Statement;
   > import java.sql.Types;
   >
   > /**
   >  * Tests simple jdbc access for memory leaks.
   >  */
   >
   >
   > public class Tbtestc {
   > 	public static void main( String[] args) {
   > 		new Tbtestc( args);
   > 	}
   >
   > 	void prtln( String msg) {
   > 		System.out.println( msg);
   > 	}
   >
   > 	void badparms( String msg)
   > 	{
   > 		prtln("");
   > 		prtln("Testc: Error: " + msg);
   > 		prtln("args:  drivername url userid pswd tabname
   > (will be deleted)");
   > 		System.exit(1);
   > 	}
   >
   >
   > 	public Tbtestc( String[] args) {
   > 		int ii;
   >
   > 		if (args.length != 5) badparms("wrong num parms");
   > 		String drivername	= args[0];
   > 		String url			= args[1];
   > 		String userid		= args[2];
   > 		String pswd			= args[3];
   > 		String tabname		= args[4];
   >
   > 	    // Connect to database and run the tests
   > 		try {
   > 			testit( drivername, url, userid, pswd, tabname);
   > 		}
   > 		catch( Exception exc) {
   > 			prtln("Tbtestc: error: " + exc);
   > 			exc.printStackTrace();
   > 		}
   > 	}
   >
   >
   > 	void testit(
   > 		String drivername,
   > 		String url,
   > 		String userid,
   > 		String pswd,
   > 		String tabname)
   > 	throws SQLException, ClassNotFoundException
   > 	{
   > 		int iterlim = 1000;
   > 		int iterdelta = 100;
   > 		int ii, jj, kk;
   > 		int ncols;
   > 		String tstg;
   > 		ResultSet rs = null;
   > 		int maxcolwidth = 30;
   >
   > 	    Connection dbcon = null;
   > 		Statement dbst = null;
   >
   > 	    // Load the driver
   > 		Class.forName( drivername);
   >
   >     	prtln("Connecting to Database URL = " + url);
   > 		dbcon = DriverManager.getConnection( url, userid, pswd);
   > 		prtln("got dbcon.");
   > 		dbst = dbcon.createStatement();
   > 		prtln("got dbst.");
   >
   > 		try { dbst.executeUpdate("drop table " + tabname); }
   > 		catch( SQLException sqe) {
   > 			prtln("could not drop table " + tabname +
   > ": " + sqe);
   > 		}
   >
   > 		dbst.executeUpdate("create table " + tabname
   > 			+ " (colstg varchar(22) not null,"
   > 			+ " colint integer not null,"
   > 			+ " primary key (colstg, colint))");
   > 		prtln("testit: created " + tabname);
   >
   > 		prtfreemem("before get catalog");
   > 		String catalog = null;
   > 		int isol = 0;
   > 		boolean readonly = false;
   > 		boolean autocommit = false;
   > 		for (kk = 0; kk < iterlim; kk++) {
   > 			catalog = dbcon.getCatalog();
   > 			isol = dbcon.getTransactionIsolation();
   > 			readonly = dbcon.isReadOnly();
   > 			autocommit = dbcon.getAutoCommit();
   > 			if (kk % iterdelta == 0) prtfreemem("after
   > get catalog: " + kk);
   > 		}
   > 		prtfreemem("after get catalog");
   > 		prtln("    catalog: " + catalog);
   > 		prtln("    transaction isolation level: " + isol);
   > 		prtln("    read only: " + readonly);
   > 		prtln("    auto commit: " + autocommit);
   >
   > 		DatabaseMetaData dbm = null;
   > 		for (kk = 0; kk < iterlim; kk++) {
   > 			dbm = dbcon.getMetaData();
   > 			if (kk % iterdelta == 0) prtfreemem("after
   > get dbm: " + kk);
   > 		}
   > 		prtfreemem("after get dbm");
   > 		String prodname = null;
   > 		String version = null;
   > 		String geturl = null;
   > 		String getuser = null;
   > 		for (kk = 0; kk < iterlim; kk++) {
   > 			prodname = dbm.getDatabaseProductName();
   > 			version = dbm.getDatabaseProductVersion();
   > 			geturl = dbm.getURL();
   > 			getuser = dbm.getUserName();
   > 			if (kk % iterdelta == 0) prtfreemem("after
   > get prodname: " + kk);
   > 		}
   > 		prtfreemem("after get prodname");
   > 		prtln("database meta data:");
   > 		prtln("    product name: " + prodname);
   > 		prtln("    version: " + version);
   > 		prtln("    URL: " + geturl);
   > 		prtln("    user: " + getuser);
   >
   > 		for (kk = 0; kk < iterlim; kk++) {
   > 			ResultSet keyrs = dbm.getPrimaryKeys(
   > 				null, null,			//
   > catalog, schema
   > 				tabname);
   > 			keyrs.close();
   > 			if (kk % iterdelta == 0) prtfreemem("after
   > get keys: " + kk);
   > 		}
   > 		prtfreemem("after get keys");
   >
   > 	}
   >
   >
   >
   > 	void prtfreemem( String msgparm) {
   > 		Runtime runtime = Runtime.getRuntime();
   > 		runtime.gc();
   > 		long totmem = runtime.totalMemory();
   > 		long freemem = runtime.freeMemory();
   > 		String msg = msgparm + ": "
   > 			+ " totmem: " + totmem
   > 			+ " freemem: " + freemem;
   > 		System.out.println( msg);
   > 	}
   >
   >
   > } // end class Tbtestc
   >
   >
   > ========== end Tbtestc.java ==========
   >
   > ---------------------------(end of broadcast)---------------------------
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