users@grizzly.java.net

Re: [spam] Re: Many extra connections when running WebSocket server or client.

From: Weiqi GAO <weiqigao_at_gmail.com>
Date: Thu, 9 May 2013 18:55:11 -0500

Thanks.

Sent from my iPhone

On May 9, 2013, at 5:07 PM, Oleksiy Stashok <oleksiy.stashok_at_oracle.com> wrote:

> Hi,
>
> it's Windows specific Java NIO Selector behavior, when you create a Selector it creates loopback connection (2 TCP connections).
> We can do nothing about that, it's how Java NIO works on Windows.
>
> Thanks.
>
> WBR,
> Alexey.
>
> On 09.05.13 14:05, Weiqi Gao wrote:
>> Hi,
>>
>> When I start a simple HttpServer using Grizzly, like this:
>>
>> import org.glassfish.grizzly.http.server.HttpServer;
>> import java.io.IOException;
>>
>> public class JustHttpServerMain {
>> public static void main(String[] args) throws IOException {
>> HttpServer server = HttpServer.createSimpleServer(".", 8080);
>> server.start();
>> System.in.read();
>> }
>> }
>>
>> I see the Java process listening on port 8080, which is what I expect, and 8 additional connections that the process makes to itself. Here's the output of "netstat -anto | grep 9536" (where 9536 is the pid):
>>
>> $ netstat -anto | grep 9536
>> TCP 0.0.0.0:8080 0.0.0.0:0 LISTENING 9536 InHost
>> TCP 127.0.0.1:49339 127.0.0.1:49340 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49340 127.0.0.1:49339 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49341 127.0.0.1:49342 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49342 127.0.0.1:49341 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49343 127.0.0.1:49344 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49344 127.0.0.1:49343 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49345 127.0.0.1:49346 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49346 127.0.0.1:49345 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49347 127.0.0.1:49348 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49348 127.0.0.1:49347 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49349 127.0.0.1:49350 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49350 127.0.0.1:49349 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49351 127.0.0.1:49352 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49352 127.0.0.1:49351 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49353 127.0.0.1:49355 ESTABLISHED 9536 InHost
>> TCP 127.0.0.1:49355 127.0.0.1:49353 ESTABLISHED 9536 InHost
>> TCP [::]:8080 [::]:0 LISTENING 9536 InHost
>>
>> This is on a Windows 7 Pro SP1 environment with 64-bit Oracle JDK 1.7.0_21.
>>
>> Am I the only one who gets the extra connections? If this is something that is known, is there an explanation (or a fix) for it?
>>
>> Thanks,
>> --
>> Weiqi Gao
>> weiqigao_at_gmail.com
>> http://weiqigao.blogspot.com/
>