Thread: 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 ==========
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)--------------------------- > TIP 4: Don't 'kill -9' the postmaster