class LogWriter implements Runnable {
Socket client;
private static ThreadLocal<Date> date = new ThreadLocal<Date>() {
@Override
protected Date initialValue() {
return new Date();
};
};
private static ThreadLocal<SimpleDateFormat> formatter = new ThreadLocal<SimpleDateFormat>() {
@Override
protected SimpleDateFormat initialValue() {
return new SimpleDateFormat("yyyy_MM_dd");
};
};
public LogWriter(Socket client) {
this.client = client;
}
public void run() {
try {
write(this.client.getInputStream(), new File(
CentralizedLogging.logsDir + File.separator
+ client.getInetAddress().getHostName() + "_"
+ getFormattedDate() + ".log"));
this.client.close();
} catch (Exception e) {
try {
e.printStackTrace();
write(new ByteArrayInputStream(e.getMessage().getBytes()),
new File(CentralizedLogging.logsDir + File.separator
+ "centralLoggingError.log"));
} catch (IOException io) {
}
}
}
public synchronized void write(InputStream in, File file)
throws IOException {
RandomAccessFile writer = new RandomAccessFile(file, "rw");
writer.seek(file.length()); // append the file content into existing if it not exist creating a new one.
writer.write(read(in));
writer.close();
}
public static byte[] read(InputStream in) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
int read = -1;
byte[] buffer = new byte[1024];
read = in.read(buffer);
do {
out.write(buffer, 0, read);
} while((read = in.read(buffer)) > -1);
return out.toByteArray();
}
Main Method
public static void main(String[] args) throws InterruptedException,
IOException {
// CentralizedLogging centralLogServer = new CentralizedLogging(args[0],Integer.parseInt(args[1]));
// new Thread(centralLogServer).start();
long start = System.currentTimeMillis() + 1000 * 20 * 60;
while(start >= System.currentTimeMillis()) {
Socket client = new Socket("bharathi-1397", 10000);
OutputStream os = client.getOutputStream();
DataOutputStream outToServer = new DataOutputStream(os);
outToServer
.write("Centralized Logging is working......".getBytes());
client.close();
}
}
I am properly closed connection . But time_wait connections is increasing . I have take a snap shot from my terminal i am posted one portion of it . Is am missing any thing ?
tcp6 0 0 127.0.0.1:46146 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:57645 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:47961 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:56716 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:49469 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:54078 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:51626 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:50143 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:59214 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:54192 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:53436 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:54547 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:55032 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:51273 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:48381 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:47532 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:56811 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:55293 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:56664 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:49242 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:51225 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:59265 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:59378 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:47997 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:47955 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:59453 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:48092 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:52462 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:59579 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:54921 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:55675 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:51140 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:57321 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:51656 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:54740 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:53600 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:59862 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:54766 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:59062 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:55702 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:50942 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:53732 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:52757 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:56430 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:49179 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:48689 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:53313 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:51161 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:57033 127.0.0.1:10000 TIME_WAIT -
tcp6 0 0 127.0.0.1:58607 127.0.0.1:10000 TIME_WAIT -
It causes any problem to my server ?. What is the reason for this ? .
I am properly closing connection but time_wait connections is increasing. Am I missing anything?
The TIME_WAIT is used by the kernel to make sure that your TCP stream does not re-use a port that may still have packets being sent to it from the remote side. The TIME_WAIT time is generally set to double the packets maximum age based on network settings.
If you are getting a number of new connections, then you will see the number of ports in TIME_WAIT increase but at some point it should stabilize unless the connection rate is also increasing. One thing to do is to grep for all of the TIME_WAIT lines, sort them and see if the port numbers are changing. If new ports are being added and old ones falling off then all is fine.
One thing to try is to make sure that your client is initiating the close() call. That would leave the TIME_WAIT on the client and not on the server. See this excellent page about TCP and the implications of TIME_WAIT on the server.
Since it seems like your server is sending a file to the client (if I'm reading your code correctly), you should consider changing your protocol to something like the following. That would cause the client to close first so most of the TIME_WAITs will be on each of the clients.
Did you see the bit about having the client make the close() first @kannan? If the server is sending a file then I would have it send the file and then wait for the client to send a "got it" message. The client can then read the file, read an EOF marker, send the "got it" and then close immediately.
Also, as an aside, you should be using try ... finally patterns in your code. Something like:
public void run() {
try {
write(this.client.getInputStream(), new File(
CentralizedLogging.logsDir + File.separator
+ client.getInetAddress().getHostName() + "_"
+ getFormattedDate() + ".log"));
} catch (Exception e) {
try {
e.printStackTrace();
write(new ByteArrayInputStream(e.getMessage().getBytes()),
new File(CentralizedLogging.logsDir + File.separator
+ "centralLoggingError.log"));
} catch (IOException io) {
}
} finally {
// always close in the finally
this.client.close();
}
}