Re: JDBC HighLoad

Stephane,

You are using this class as a singleton in a multithreaded environment ???

Dave

Stéphane RIFF wrote:

> Stéphane RIFF wrote:
>
>> Hi i have a java aplication which connect to postgresql via jdbc.
>> This app make a lot of request per second.
>> The problem is that i get delayed records between the moment the
>> informations arrived via socket to java and
>> the moment it's recorded in the database. It seems that jdbc wait
>> before inserting/updating the db because
>> they are to much requests.
>> For testing i made a little app in c using libpq to see if problem
>> persist and there no delay.
>>
>> So i'd like to know a way to speed up jdbc if possible ???
>>
>>
> Here my connection class, is there something wrong ?
>
> import java.io.*;
> import java.util.*;
> import java.sql.*;
> import java.text.*;
> import javax.sql.DataSource;
> import org.postgresql.jdbc3.Jdbc3PoolingDataSource;
>
> import org.apache.log4j.Logger;
> import org.apache.log4j.PropertyConfigurator;
>
> public class SQLoader {
> private Jdbc3PoolingDataSource datasource ;
> //query object gps
> private PreparedStatement pstmt_gps ;
> //query object io
> private PreparedStatement pstmt_io ;
> //query object gps
> private PreparedStatement pstmt_ugps ;
> //query object io
> private PreparedStatement pstmt_uio ;
> //query object gps
> private PreparedStatement pstmt_hgps ;
> //query object io
> private PreparedStatement pstmt_hio ;
> //singleton class
> private final static SQLoader myRef = new SQLoader();
> //Log4j logger object
> private static Logger logger =
> Logger.getLogger(SQLoader.class.getName());
> //jdbc driver
> private String driver ;
> //jdbc connection string
> private String jdbcConnectionString ;
> //database user
> private String dbUser ;
> //database password
> private String dbPwd ;
> /**
> * Private constructor
> *
> * @since 1.0
> */
> private SQLoader() {}
> /**
> * Give access to the unique instance of this class
> *
> * @return The instance
> * @since 1.0
> */
> public static SQLoader getRef()
> {
> return myRef ;
> }
> public void connect(String driver,String dbc, String dbu, String
> dbp)
> {
> Connection m_conn = null;
> try {
> datasource = setupDataSource(dbc);
> }catch(Exception e){
> logger.fatal(e.toString());
> System.exit(-1);
> }
> }
> private void prepareQuery(Connection c)
> {
> try
> {
> //Construct predefined query
> String qry = "INSERT INTO gps_frame (" +
> "\"sbox_id\"," +
> "\"gps_date\"," +
> "\"badge_id\"," +
> "\"gmt_creation_date\"," +
>
> "\"wgs84_position\","+
> "\"speed\"," +
> "\"altitude\","+
> "\"heading\","+
> "\"validity\"," +
> "\"geom\")" +
> " VALUES( ?,?,?,?,?,?,?,?,?,?)";
> pstmt_gps = c.prepareStatement(qry);
>
> String qry1 = "INSERT INTO io_frame ("+
> "\"sbox_id\","+
> "\"gps_date\","+
> "\"io_type\","+
> "\"io_rank\","+
> "\"io_value\")"+
> " VALUES( ?,?,?,?,?)";
> pstmt_io = c.prepareStatement(qry1);
>
> String uqry = "UPDATE gps_frame SET "+
> "\"gps_date\"=?,"+
> "\"badge_id\"=?,"+
> "\"gmt_creation_date\"=?,"+
> "\"wgs84_position\"=?,"+
> "\"speed\"=?,"+
> "\"altitude\"=?,"+
> "\"heading\"=?,"+
> "\"validity\"=?,"+
> "\"geom\"=?"+
> " WHERE \"sbox_id\"=?";
> pstmt_ugps = c.prepareStatement(uqry);
>
> String uqry1 = "UPDATE io_frame SET "+
> "\"gps_date\"=?,"+
> "\"io_value\"=?"+
> " WHERE \"sbox_id\"=? AND \"io_rank\"=? AND
> io_type=?";
> pstmt_uio = c.prepareStatement(uqry1);
>
> qry = "INSERT INTO gps_frame_history (" +
> "\"sbox_id\"," +
> "\"gps_date\"," +
> "\"badge_id\"," +
> "\"gmt_creation_date\"," +
>
> "\"wgs84_position\","+
> "\"speed\"," +
> "\"altitude\","+
> "\"heading\","+
> "\"validity\"," +
> "\"geom\")" +
> " VALUES( ?,?,?,?,?,?,?,?,?,?)";
> pstmt_hgps = c.prepareStatement(qry);
>
> qry1 = "INSERT INTO io_frame_history ("+
> "\"sbox_id\","+
> "\"gps_date\","+
> "\"io_type\","+
> "\"io_rank\","+
> "\"io_value\")"+
> " VALUES( ?,?,?,?,?)";
> pstmt_hio = c.prepareStatement(qry1);
> }catch( java.sql.SQLException e)
> {
> logger.fatal(e.toString());
> System.exit(-1);
> }
> }
> /**
> * Disconnect from DB
> *
> * @since 1.0
> */
> public void disconnect()
> {
> try {
> shutdownDataSource(datasource);
> } catch(Exception e){
> logger.fatal(e.toString());
> System.exit(-1);
> }
> }
> public void saveTrame(String boxID, String badgeID, String
> gpsDate, double speed,
> String wgs84, double altitude,
> double azimuth,
> String validity, String geom,
> String sysDate, int[] input, int[] output)
> { Connection m_conn = null;
> try
> {
> m_conn = datasource.getConnection();
> m_conn.setAutoCommit(false);
> prepareQuery(m_conn);
> //set query values for update gps_frame
> pstmt_ugps.setString(1, gpsDate);
> pstmt_ugps.setString(2, badgeID);
> pstmt_ugps.setString(3, sysDate);
> pstmt_ugps.setString(4, wgs84);
> pstmt_ugps.setDouble(5, speed);
> pstmt_ugps.setDouble(6, altitude);
> pstmt_ugps.setDouble(7, azimuth);
> pstmt_ugps.setString(8, validity);
> pstmt_ugps.setString(9, geom);
> pstmt_ugps.setString(10, boxID);
> if(pstmt_ugps.executeUpdate()==0)
> { //if no frame already exists insert it
> pstmt_gps.setString(1, boxID);
> pstmt_gps.setString(2, gpsDate);
> pstmt_gps.setString(3, badgeID);
> pstmt_gps.setString(4, sysDate);
> pstmt_gps.setString(5, wgs84);
> pstmt_gps.setDouble(6, speed);
> pstmt_gps.setDouble(7, altitude);
> pstmt_gps.setDouble(8, azimuth);
> pstmt_gps.setString(9, validity);
> pstmt_gps.setString(10, geom);
> pstmt_gps.executeUpdate();
> for(int i = 0; i < input.length; i++)
> {
> pstmt_io.setString(1, boxID);
> pstmt_io.setString(2, gpsDate);
> pstmt_io.setString(3, "i");
> pstmt_io.setInt(4, (i+1));
> pstmt_io.setInt(5, input[i]);
> pstmt_io.executeUpdate();
> }
> for(int o = 0; o < output.length; o++)
> {
> pstmt_io.setString(1, boxID);
> pstmt_io.setString(2, gpsDate);
> pstmt_io.setString(3, "o");
> pstmt_io.setInt(4, (o+1));
> pstmt_io.setInt(5, output[o]);
> pstmt_io.executeUpdate();
> }
> }else
> { //if frame already exists in gps_frame update his io
> for(int i = 0; i < input.length; i++)
> {
> pstmt_uio.setString(1, gpsDate);
> pstmt_uio.setInt(2, input[i]);
> pstmt_uio.setString(3, boxID);
> pstmt_uio.setInt(4, (i+1));
> pstmt_uio.setString(5,"i");
> pstmt_uio.executeUpdate();
> }
> for(int o = 0; o < output.length; o++)
> {
> pstmt_uio.setString(1, gpsDate);
> pstmt_uio.setInt(2, output[o]);
> pstmt_uio.setString(3, boxID);
> pstmt_uio.setInt(4, (o+1));
> pstmt_uio.setString(5,"o");
> pstmt_uio.executeUpdate();
> }
> }
> //insert in hisory
> pstmt_hgps.setString(1, boxID);
> pstmt_hgps.setString(2, gpsDate);
> pstmt_hgps.setString(3, badgeID);
> pstmt_hgps.setString(4, sysDate);
> pstmt_hgps.setString(5, wgs84);
> pstmt_hgps.setDouble(6, speed);
> pstmt_hgps.setDouble(7, altitude);
> pstmt_hgps.setDouble(8, azimuth);
> pstmt_hgps.setString(9, validity);
> pstmt_hgps.setString(10, geom);
> pstmt_hgps.executeUpdate();
>
> for(int i = 0; i < input.length; i++)
> {
> pstmt_hio.setString(1, boxID);
> pstmt_hio.setString(2, gpsDate);
> pstmt_hio.setString(3, "i");
> pstmt_hio.setInt(4, (i+1));
> pstmt_hio.setInt(5, input[i]);
> pstmt_hio.executeUpdate();
> }
> for(int o = 0; o < output.length; o++)
> {
> pstmt_hio.setString(1, boxID);
> pstmt_hio.setString(2, gpsDate);
> pstmt_hio.setString(3, "o");
> pstmt_hio.setInt(4, (o+1));
> pstmt_hio.setInt(5, output[o]);
> pstmt_hio.executeUpdate();
> }
> m_conn.commit();
> }
> catch(java.sql.SQLException e){
> String msg = e ;
> logger.warn(msg);
> }
> finally {
> try { m_conn.close(); } catch(Exception e) { }
> }
> }
> public Jdbc3PoolingDataSource setupDataSource(String connectURI) {
> Jdbc3PoolingDataSource ds = new Jdbc3PoolingDataSource();
> ds.setDataSourceName("Xxx");
> ds.setServerName("xxx.xxx.xxx.xxx");
> ds.setDatabaseName("xxxxxxxxxxxxx");
> ds.setUser("xxxxx");
> ds.setPassword("xxxxx");
> ds.setMaxConnections(10);
> return ds;
> }
> public static void shutdownDataSource(DataSource ds) throws
> SQLException {
> }
> }
>
> When i highload postgresql with a multi-threaded serverSocket using
> this class,
> my app freezes very quickly and all my connection are in idle state.
> It seems that the connection aren't released.
>
> It don't know what i can do if someone could help ???
> Thanks
>
>

--
Dave Cramer
http://www.postgresintl.com
519 939 0336
ICQ#14675561