Handling concurrent users

Question

hi guys,
I developed an application to be used be 1500 users and deployed to tomcat. It hangs after working for a while how can i resolve this

Answer 1

I stopped all application running on the server and tested it after the fifth time it hanged. Instead of using transaction, i changed the code to be using stored procedure.This is the code i used to call the stored procedure that freeze the system
try{
ConnectPoolhr C = null;
CallableStatement proc = null;
C = new ConnectPoolhr();
String query = "{ call L1UPDATE(?, ?, ?, ?, ?) }";
//C.autoCommit(false);
proc = C.prepareCall(query);
proc.setString(1, sf.getEmplid().toLowerCase());
proc.setString(2, sf.getAppr_yr());
proc.setString(3, sf.getHasl2linkno());
proc.setString(4, sf.getHierarchyType().getLink_no());
proc.setString(5, sf.getL2empid().toUpperCase());
proc.execute();
catch(SQLException sp){
System.out.print("\n\n\n\n\n\n\n\n\n\n\n\n\n\n impossible to close \n\n\n\\n\n\n\n\n\n\n\n");
finally {
try{  
//ps.close();
// pst.close();
proc.close();
C.dispose();
catch(SQLException sq){
System.out.print("\n\n\n\n\n\n\n\n\n\n\n\n\n\n impossible for finally \n\n\n\\n\n\n\n\n\n\n\n");
}}