title: org.postgresql.util.PSQLException: The connection attempt failed
body: <p>I am connecting to postgres data base using java web services (<strong>apache axis</strong>) with <strong>JDBC</strong> connections to get the data.But suddenly in most of times i am getting an exception of <code>org.postgresql.util.PSQLException: The connection attempt failed.</code> and some times it is working fine. Here I am using many prepared statements. My sample code is </p>
  
  <pre><code>Connection connection=null;
  try
  {
      Class.forName(driver);
      connection = DriverManager.getConnection(url, username, password);
      ps1=connection.prepareStatement("select * from emp");
      rs1=ps1.executeQuery();
      while(rs1.next())
      {            
          ps2=connection.prepareStatement("select * from dept where dept_no="+rs1.getInt("dept_no"));
          rs2=ps2.executeQuery();
          while(rs2.next())
          {
              ................
              ................
          }
      }
  }
  catch(Exception e)
  {
      System.out.println("Exception occurred is"+e.getMessage());            
  }
  finally
  {
      try{if(rs1!=null)rs1.close();}catch(Exception e){ System.out.println("*1closing error---&gt;"+e);}
      try{if(ps1!=null)ps1.close();}catch(Exception e){ System.out.println("**1closing error---&gt;"+e);}
      try{if(rs2!=null)rs2.close();}catch(Exception e){ System.out.println("*2closing error---&gt;"+e);}
      try{if(ps2!=null)ps2.close();}catch(Exception e){ System.out.println("**2closing error---&gt;"+e);}
      try{if(connection!=null)connection.close();}catch(Exception e){ System.out.println("***closing error---&gt;"+e);}
  }
  </code></pre>
  
  <p>stack trace about this exception is </p>
  
  <pre><code>org.postgresql.util.PSQLException: The connection attempt failed.
      at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:137)
      at org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:66)
      at org.postgresql.jdbc2.AbstractJdbc2Connection.&lt;init&gt;(AbstractJdbc2Connection.java:124)
      at org.postgresql.jdbc3.AbstractJdbc3Connection.&lt;init&gt;(AbstractJdbc3Connection.java:30)
      at org.postgresql.jdbc3.Jdbc3Connection.&lt;init&gt;(Jdbc3Connection.java:24)
      at org.postgresql.Driver.makeConnection(Driver.java:386)
      at org.postgresql.Driver.connect(Driver.java:260)
      at java.sql.DriverManager.getConnection(Unknown Source)
      at java.sql.DriverManager.getConnection(Unknown Source)
      at com.codon.service.WareHouseServer.get_picks(WareHouseServer.java:7415)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.axis.providers.java.RPCProvider.invokeMethod(RPCProvider.java:397)
      at org.apache.axis.providers.java.RPCProvider.processMessage(RPCProvider.java:186)
      at org.apache.axis.providers.java.JavaProvider.invoke(JavaProvider.java:323)
      at org.apache.axis.strategies.InvocationStrategy.visit(InvocationStrategy.java:32)
      at org.apache.axis.SimpleChain.doVisiting(SimpleChain.java:118)
      at org.apache.axis.SimpleChain.invoke(SimpleChain.java:83)
      at org.apache.axis.handlers.soap.SOAPService.invoke(SOAPService.java:454)
      at org.apache.axis.server.AxisServer.invoke(AxisServer.java:281)
      at org.apache.axis.transport.http.AxisServlet.doPost(AxisServlet.java:699)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
      at org.apache.axis.transport.http.AxisServletBase.service(AxisServletBase.java:327)
      at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
      at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
      at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
      at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
      at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
      at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
      at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
      at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
      at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298)
      at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:857)
      at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588)
      at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
      at java.lang.Thread.run(Unknown Source)
  Caused by: java.net.SocketException: Connection reset
      at java.net.SocketInputStream.read(Unknown Source)
      at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:135)
      at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:104)
      at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:73)
      at org.postgresql.core.PGStream.ReceiveChar(PGStream.java:259)
      at org.postgresql.core.v3.ConnectionFactoryImpl.doAuthentication(ConnectionFactoryImpl.java:254)
      at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:95)
      ... 37 more
  </code></pre>
  
  <p>I checked the postgres logs and i found the following statements in different cases</p>
  
  <p>1.WARNING:  worker took too long to start; cancelled.</p>
  
  <p>2.could not reattach to shared memory (key=...., addr=.....): 487.</p>
  
  <p>3.could not receive data from client: No connection could be made because the target machine actively refused it.</p>
  
  <p>4.unexpected EOF on client connection.</p>
  
  <p>please help me.Thanks In advance</p>