Looking for clarification on network latency issue vs drive mapping

Question

Hi,
I am seeing this as mystery and not getting crystal clear idea on the reason for the issue. Issue is related to the performance of the application interms of time it is taking in processing the input file.
I wrote a swing application, which is a client application. Which takes some parameters like server name and iphostaddress and connects to the Process Server which is, responsible for processing client application requests. Client application will communicate with process server through TCP/IP connection and process the input file and returns the decisions back to the user through the output file.
Below is the scenarios I am using for launching the application:
1. If both client application and server are running locally in my desktop the time it is taking to process the input file is 2 minutes.
2. If client is running my application and server is running remotely on wondows server, it's taking 13 minutes to process same input file.
3. To reduce the time in scenario2, I installed the client appliation also on the remote server ( so that both client and server application are running on the windows server). and mapped the server's share drive to my desktop. And launched the application from my desktop (from U drive, where application is mapped), now it's taking 10 minutes to process the same input file.
I am struggling in understanding why it's taking that long in scenario 3. Because application is installed locally on the server and input file and output files also copied onto the U drive. Sometimes thinking am I launching the application in the right way or not?
Can somebody explain me, if we launch the remote java application through drive mapping will there be network latency there eventhough everything is there on the server (U drive)? Here I need to tell one more scenario 4, If loginto the remote windows server and launch the client application time it's taking to process the same input file is about a minute.
Below are some more details on the issue: I am not encoding the file, I am using third party application, which provides an API to communicate with the process server. Just using the API methods and classes to pass the input file data to server. I have used the 'tracert' command for the remote server and I am seeing 8 hops between my desktop and remote server. I even installed network sniffer tool in my laptop and captured the files when application running.
The input file has 140000 records (text lines with comma delimited) of 6.271MB in size. I have posted to understand the time it is taking in scenario3, where evrything is on mapped drive (i.e, client application and input file are technically recides on the server right?) , but client application is launched from desktop. The reason I am doing this way is, instead of log-in into the remote server, user can easily launch the application from the desktop. So, when I try to launch the application this way, this doesn't count as if client application is running local to the server? Will it becomes remote (I have even captured the network traffic file in this scenario too, and I have seen the comminication between my desktop ip address to server ip address and server is taking abour 3.84 milliseconds for each item to respond to client, I think it's just travel time not the process time). I am assuming, even when application launched from drive that is mapped, it should take about 1 minute (the time taking when I launch the aplication after log-into the server,not through drive mapping) to prcess input file as everything is on the server.
Thanks in advance,
Jyothi

Answer 1

reading and writing the data shouldn't be the problem, its what you are doing with the data which will be taking all the time.
Try this
public class WriteFile {
    public static void main(String... args) throws IOException {
        String filename = "record.csv";
        int records = 140 * 1000;
        int values = 6;
            long start = System.nanoTime();
            PrintWriter pw = new PrintWriter(new BufferedWriter(new FileWriter(filename)));
            for (int r = 0; r < records; r++) {
                for (int i = 0; i < values; i++) {
                    if (i > 0)
                        pw.print(',');
                    pw.print(r * 10 + i);
                pw.println();
            pw.close();
            long time = System.nanoTime() - start;
            System.out.printf("Time to write %,d records was %.3f sec. file size=%.3fMB%n",
                    records, time / 1e9, new File(filename).length() / 1e6);
            long start = System.nanoTime();
            BufferedReader br = new BufferedReader(new FileReader(filename));
            String line;
            while ((line = br.readLine()) != null) {
                // do some work.
                String[] parts = line.split(",");
                int[] nums = new int[parts.length];
                for (int i = 0; i < parts.length; i++)
                    nums[i] = Integer.parseInt(parts);
br.close();
long time = System.nanoTime() - start;
System.out.printf("Time to read %,d records was %.3f sec%n",
records, time / 1e9);
PrintsTime to write 140,000 records was 0.462 sec. file size=6.193MB
Time to read 140,000 records was 0.792 sec