hi pgpool Expert my architecture as follows: Master/Slave with Streaming Replication and pgpool-II version of pgpool-II is pgpool-II.3.0.4 version of PostgreSQL is 9.0.2 I am using pgpool works as master/slave sub mode stream and pgpool key configuration is: ===================================================================================================== num_init_children=100 max_pool=4 child_life_time=60 connection_life_time=0 child_max_connections=0 client_idle_limit=0 connection_cache=true ===================================================================================================== and java jdbc connection test code as fllows: ===================================================================================================== import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class TestPgpool { public static void main(String[] args) { for(;;){ Thread th = new Thread(new TestThread()); th.start(); try { Thread.sleep(10); } catch (InterruptedException e) { System.out.println("1--------------"); e.printStackTrace(); System.out.println("1--------------"); } } } static class TestThread implements Runnable{ public void run() { Connection con = null; Statement stmt = null; try { Class.forName("org.postgresql.Driver"); con = DriverManager.getConnection( "jdbc:postgresql://192.168.1.116:9999/spring250_20100630_705", "postgres","postgres"); stmt = con.createStatement(); String sql = "SELECT * FROM bb_member limit 1"; ResultSet rs = stmt.executeQuery(sql); System.out.print("OK("); while(rs.next()){ System.out.print(rs.getInt(1) + "=" + rs.getString(2) + " "); } System.out.println(")"); stmt.close(); con.close(); } catch (SQLException e) { System.out.println("2--------------"); e.printStackTrace(); System.out.println("2--------------"); } catch (ClassNotFoundException e) { e.printStackTrace(); } } } } ===================================================================================================== question: I do some db falt tests 1)the test code run always connect pgpool, 2)test master or slave go down but when mster or slave go down ,java code throws exception : org.postgresql.util.PSQLException: An I/O error occurred while sending to the backend org.postgresql.util.PSQLException: The connection attempt failed. the error happened once for little time,then goes normal. what should I do to solve this problem?and show the reason about the matter. thanks for any help jeno -- View this message in context: http://postgresql.1045698.n5.nabble.com/pgpool-master-or-slave-goes-down-java-access-error-tp4692837p4692837.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance