Post Reply 
 
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
controller cannot see minimServer
15-08-2012, 15:48
Post: #11
RE: controller cannot see minimServer
(15-08-2012 13:43)psme Wrote:  Simple wired LAN. And it's the same single PC, running both server and controller! Why my network "problem" matter in this case? Network (and internet) works fine on my PC in other software!

I'm slightly a geek myself so I can "understand" something maybe wrong in my setup. And I'm willing to deal with it. But if this network playback need to takeoff with average user, something need to be done...

PS: remind myself ranting does not help... Smile

Was the problem cured by rebooting the PC?
Find all posts by this user
Quote this message in a reply
16-08-2012, 03:19
Post: #12
RE: controller cannot see minimServer
So I rebooted the Win7 PC. Start minimServer again, and all is fine. Desktop Kinsky on the same PC always find minimServer. iPad via wi-fi also always find minimServer. Btw, on this PC with both minimServer and Kinsky controller, the PC is always using a fixed static IP (192.168.1.xxx). iPad on wi-fi is using DHCP via the router.

And I have a Qnap 212 with minimServer 0.52. The minimServer on the Qnap has exactly the same problem. Desktop Kinsky and iPad Kinsky (and other controller program/app) could not see the Qnap minimServer unless I let the controller wait a LONG time. Or I need to do a "restart" via minimWatch.

Since a reboot of the PC brought back the PC minimServer. I thought I need to reboot the NAS as well (the NAS is on DHCP, though I see that it always get the same IP). But before I reboot the NAS, I went to Qnap web admin->QPKG package, "Disable" minimServer, then "Enable" minimServer. Now, the Qnap minimServer is visible all the time! I don't need to reboot the NAS itself!

So, my guess is, it looks like the problem is on minimServer itself! And it seems this "disappear" problem only occur after minimServer is running for a long time, maybe several days or more, and with multiple "restart" operation as I'm adding albums to the library almost everyday.

Maybe... after a while, something is "stuck" in minimServer, or it's ohNet stack, and cause minimServer fail to subscribe the multi-cast group, hence minimServer does not see UPnP discovery message anymore. Though it can still send multi-cast message directly to the multi-cast address when it emit "alive" message...

Next time when minimServer act up, I will totally quit it, then re-run it...
Find all posts by this user
Quote this message in a reply
16-08-2012, 06:48
Post: #13
RE: controller cannot see minimServer
(16-08-2012 03:19)psme Wrote:  So I rebooted the Win7 PC. Start minimServer again, and all is fine. Desktop Kinsky on the same PC always find minimServer. iPad via wi-fi also always find minimServer. Btw, on this PC with both minimServer and Kinsky controller, the PC is always using a fixed static IP (192.168.1.xxx). iPad on wi-fi is using DHCP via the router.

And I have a Qnap 212 with minimServer 0.52. The minimServer on the Qnap has exactly the same problem. Desktop Kinsky and iPad Kinsky (and other controller program/app) could not see the Qnap minimServer unless I let the controller wait a LONG time. Or I need to do a "restart" via minimWatch.

Since a reboot of the PC brought back the PC minimServer. I thought I need to reboot the NAS as well (the NAS is on DHCP, though I see that it always get the same IP). But before I reboot the NAS, I went to Qnap web admin->QPKG package, "Disable" minimServer, then "Enable" minimServer. Now, the Qnap minimServer is visible all the time! I don't need to reboot the NAS itself!

So, my guess is, it looks like the problem is on minimServer itself! And it seems this "disappear" problem only occur after minimServer is running for a long time, maybe several days or more, and with multiple "restart" operation as I'm adding albums to the library almost everyday.

Maybe... after a while, something is "stuck" in minimServer, or it's ohNet stack, and cause minimServer fail to subscribe the multi-cast group, hence minimServer does not see UPnP discovery message anymore. Though it can still send multi-cast message directly to the multi-cast address when it emit "alive" message...

Next time when minimServer act up, I will totally quit it, then re-run it...

There is no code in MinimServer or ohNet to subscribe to a multicast group. This is handled at lower levels in the TCP/UDP OS stack.

All these symptoms point to a network problem. It sounds like an issue with IGMP snooping in your router or switch. The router or switch sends out IGMP query commands and looks for responses. If the QNAP or PC fails to respond to these queries (for whatever reason), the router or switch removes it from the multicast group and never sends it any more multicast messages.

I have set up my switch to permanently add certain ports to the SSDP multicast group so they are excluded from IGMP snooping and possible removal from the SSDP group. If you can do this for the router or switch ports to which your NAS and PC are connected, I would recommend doing that. Alternatively, you could disable IGMP snooping in your router or switch configuration (probably a simpler solution).
Find all posts by this user
Quote this message in a reply
16-08-2012, 08:13
Post: #14
RE: controller cannot see minimServer
I didn't reboot the Qnap. "Disable", then "Enable" minimServer via Qnap web admin solves the problem. So I guess I don't really need to reboot my Win7 PC either. I should "quite/close", then re-run minimServer on my PC.

From a non technical end user point of view, it seems the problem comes from minimServer, as all other network applications work fine, and I don't really need to reboot any hardware.

Anyway, will try those network stuff you mentioned...
Find all posts by this user
Quote this message in a reply
16-08-2012, 08:42
Post: #15
RE: controller cannot see minimServer
(16-08-2012 08:13)psme Wrote:  I didn't reboot the Qnap. "Disable", then "Enable" minimServer via Qnap web admin solves the problem. So I guess I don't really need to reboot my Win7 PC either. I should "quite/close", then re-run minimServer on my PC.

That might work, depending on how the Windows networking stack handles this situation. If this happens again on the PC, please try doing this and let me know if it fixes the problem.

Note that just because this makes MinimServer show up in the control point doesn't mean the problem is fixed. You'd need to close and restart the control point to be sure of that.

Quote:From a non technical end user point of view, it seems the problem comes from minimServer,

Yes, I agree that a non-technical user would think that, which is a problem. The arcane mysteries of IGMP snooping and multicast groups aren't something that users should need to know about. Unfortunately, the use of SSDP discovery and multicast messages is an unavoidable part of the UPnP architecture.

Quote:as all other network applications work fine, and I don't really need to reboot any hardware.

I don't accept that all other network applications work fine. I could probably find 100 threads or posts on the Linn forum over the last couple of years (not related to MinimServer) saying that Kinsky/Chorus/Songbook can't discover the DS or the server until one or other of these components is restarted. These problems are likely to be caused by similar network issues.

Quote:Anyway, will try those network stuff you mentioned...

I'll be interested to hear whether it solves the problem. I've had no more of these problems since I made these changes to my own network. Also, it's a good thing that you're not trying to do this with a wireless LAN, which introduces yet another dimension of multicast complexity.
Find all posts by this user
Quote this message in a reply
16-08-2012, 08:53
Post: #16
RE: controller cannot see minimServer
Hi, i once had a UPnP related network issue (before using MinimServer). In my network, i've two D-LINK routers, whereby one of them is configured as access point. In both routers I had enabled the option 'UPnP', which seemed reasonable to me (although i don't really know what this option brings about).
This resulted in heavy data transfer between both these routers and in my control points some media servers appeared and disappeared in irregular intervals. Disabling the 'UPnP' option in both routers solved this problem for me.
Find all posts by this user
Quote this message in a reply
16-08-2012, 09:42
Post: #17
RE: controller cannot see minimServer
A quick search on ohNet gives:

https://github.com/openhome/ohNet/blob/master/Os/Os.h

With a function call like:
int32_t OsNetworkBindMulticast(THandle aHandle, TIpAddress aAdapter, TIpAddress aMulticast, uint32_t aPort);

It seems ohNet does handle some multicast binding operation. If for some reason such function fail, then ohNet may not receive any multicast message, hence causing the problem.

Or I have no idea what I'm talking about! Smile

Anyway, hope this problem happen again so I can do some network sniffing...
Find all posts by this user
Quote this message in a reply
16-08-2012, 11:23
Post: #18
RE: controller cannot see minimServer
(16-08-2012 09:42)psme Wrote:  A quick search on ohNet gives:

https://github.com/openhome/ohNet/blob/master/Os/Os.h

With a function call like:
int32_t OsNetworkBindMulticast(THandle aHandle, TIpAddress aAdapter, TIpAddress aMulticast, uint32_t aPort);

It seems ohNet does handle some multicast binding operation. If for some reason such function fail, then ohNet may not receive any multicast message, hence causing the problem.

Or I have no idea what I'm talking about! Smile

This ohNet code is binding to a multicast socket, not subscribing to a multicast group. Subscribing is a lower-level IGMP protocol that is implemented by the OS networking stack. If this bind call were to fail, MinimServer would never be able to receive any multicast messages, not even when it's first started.

The IGMP subscription should be maintained by the OS networking stack as long as the multicast socket is bound by the ohNet library in the MinimServer process. On Windows, you can check this by issuing the netstat -a -o command. In the output, you'll see a section like this:
Code:
UDP    192.168.0.14:123       *:*                                    2292
UDP    192.168.0.14:427       *:*                                    3996
UDP    192.168.0.14:1030      *:*                                    2508
UDP    192.168.0.14:1900      *:*                                    16932
UDP    192.168.0.14:1900      *:*                                    2508
UDP    192.168.0.14:1900      *:*                                    2508
UDP    192.168.0.14:5353      *:*                                    1892

The number on the right is the process ID of the owning process (16932 for MinimServer). If the bind call has failed, this entry won't be present.

Quote:Anyway, hope this problem happen again so I can do some network sniffing...

I think you'll find that the IGMP queries for the SSDP multicast group are no longer being received by the device (PC or QNAP). If the multicast listening socket 1900 is still bound by the MinimServer process and the IGMP queries aren't being received, this would be conclusive evidence of a network problem.
Find all posts by this user
Quote this message in a reply
20-08-2012, 03:40
Post: #19
RE: controller cannot see minimServer
This morning my PC and QNAP minimServer couldn't be found again. So I run some tests. And IMO it seems minimServer lost the socket 1900 bound, while foobar2000 and Asset UPnP work fine on 1900. It's not my network problem that's quite sure!

Attached a wireshark capture screen:
- close all app on iPad, iPad IP is 192.168.1.11 (DHCP)
- start capture on PC, PC IP is 192.168.1.120 (static IP)
- start Kinksy on iPad, Kinsky found foobar2000 and Asset UPnP servers, couldn't see both PC and QNAP minimServer
- stop capture

As you can see, my PC receives SSDP fine, and I suppose foobar2000 and Asset UPnP responding fine.

Also attached a netstat -nab capture. There are only 4 programs bounded 1900. They are 3 foobar2000 (Yes, I have 3 foobar2000 instant on the PC!), and a Asset UPnP, but no java for minimServer.

Both PC and QNAP minimServer still work fine if I wait long enough for their 15mins apart "alive" message.


Attached File(s) Thumbnail(s)
       
Find all posts by this user
Quote this message in a reply
20-08-2012, 08:40
Post: #20
RE: controller cannot see minimServer
(20-08-2012 03:40)psme Wrote:  This morning my PC and QNAP minimServer couldn't be found again. So I run some tests. And IMO it seems minimServer lost the socket 1900 bound, while foobar2000 and Asset UPnP work fine on 1900. It's not my network problem that's quite sure!

Attached a wireshark capture screen:
- close all app on iPad, iPad IP is 192.168.1.11 (DHCP)
- start capture on PC, PC IP is 192.168.1.120 (static IP)
- start Kinksy on iPad, Kinsky found foobar2000 and Asset UPnP servers, couldn't see both PC and QNAP minimServer
- stop capture

As you can see, my PC receives SSDP fine, and I suppose foobar2000 and Asset UPnP responding fine.

Also attached a netstat -nab capture. There are only 4 programs bounded 1900. They are 3 foobar2000 (Yes, I have 3 foobar2000 instant on the PC!), and a Asset UPnP, but no java for minimServer.

Both PC and QNAP minimServer still work fine if I wait long enough for their 15mins apart "alive" message.

Thanks very much for producing this detailed information. I'll report this problem on the ohNet forum.

Is it always the case that both the PC MinimServer instance and the QNAP MinimServer instance stop listening to port 1900 at the same time? This could be important for discovering what is causing the problem.
Find all posts by this user
Quote this message in a reply
Post Reply 


Forum Jump:


User(s) browsing this thread: 1 Guest(s)