Well..by "busy" I mean he's got only 2 idle cores when running.  The other 6
are not pegged at all but run 25-50% or so.
73
Mike W9MDB

-----Original Message-----
From: KI7MT [mailto:[email protected]] 
Sent: Wednesday, July 29, 2015 11:26 PM
To: WSJT software development
Subject: Re: [wsjt-devel] UDP messages dropped

I wouldn't think the box is loaded to hard with an 8350 engine, those have a
bit of pep to them, unless he's go allot of background tasking going on.

Way OT here, but:  I've had a pile of the AMD FX Black edition CPU's at one
point, and still have a couple in the basement running as servers.
Early models were not too good, but the 8-Series seems ok.

My next build is going to be on a Tyan or Supermicro motherboard, with at
least 2x 6-Series Opteron's, like the 6344's or there about would be nice..
I'd like a 4-hole motherboard, but that can get expensive in a hurry :-)

73's
Greg, KI7MT

On 07/29/2015 09:48 PM, Michael Black wrote:
> Ran some tests and confirmed WSJT-X was sending out all packets.
> Interesting that when we used multicast no packets got dropped 
> ever.only when using unicast localhost.
> 
>  
> 
> Laurie said JTAlert only has a 128 byte buffer so that may explain the 
> problem.  He's aware now and hopefully we'll have a fix soon.
> 
>  
> 
> I have to write a test program for my friend as his system appears to 
> be single-threading WSJT-X.  He's running a Flex 3000 so his 8-core 
> system is still pretty busy but the JT9 decodes have a noticeable 
> delay after the JT65 and are all bunched together.
> 
> So I'll create a program to test how many cores his system reports.  
> Is an AMD 8350 CPU.
> 
>  
> 
> 73
> 
> Mike W9MDB
> 
>  
> 
> From: Bill Somerville [mailto:[email protected]]
> Sent: Wednesday, July 29, 2015 10:30 AM
> To: [email protected]
> Subject: Re: [wsjt-devel] UDP messages dropped
> 
>  
> 
> On 29/07/2015 16:19, Michael Black wrote:
> Hi Mike,
> 
> Actually just tested and looks like JTAlert is doing multicast too.  
> So I'll see about tracking this with him.
> 
> That can't be so if you cannot change the server address, multicast 
> will only work with a multicast group address as it requires 
> cooperation from the NIC and any routers in the network path.
> 
> Beware of running multiple servers on the same host without multicast 
> addressing, in that case each datagram will only be delivered to one 
> application and appear dropped to the other(s).
> 
> 
> 
> I watched his system for a while and didn't see interspersed JT9's but 
> I'll watch close next time.
> 
> Gotta' get some activity on the bands to see this I think.  I'll watch 
> my own system but can't say I've noticed this (and not sure I would 
> have either since I wasn't looking for it).
> 
> Was really obvious on his systems since he doesn't have many JT9's and 
> they were all missing from JTAlert.
> 
>  
> 
> I'm not sure of the underlying logic which causes UDP reordering.  I 
> went through an argument with a banking software firm many years ago 
> having to inform them that TCP wasn't a guaranteed protocol which they 
> though it was and they were blaming our software for dropping 
> transactions when it wasn't our fault at all and they finally had to 
> add another layer of ACK/NAK to the transactions to ensure end-to-end
integrity even over dropped connections.
> 
> UDP reordering usually requires a complex network of routers (the 
> Internet
> usually) it can happen if a router fails, has to retry or, decides a 
> lower cost path is possible. Not really relevant to our application 
> although WSJT-X doesn't make any assumptions about where on the 
> Internet the UDP server lives.
> 
> 
> 
>  
> 
> Thanks and I'll let you know the results.
> 
>  
> 
> 73
> 
> Mike W9MDB
> 
> 73
> Bill
> G4WJS.
> 
> 
> 
>  
> 
> From: Bill Somerville [mailto:[email protected]]
> Sent: Wednesday, July 29, 2015 10:08 AM
> To: [email protected]
> Subject: Re: [wsjt-devel] UDP messages dropped
> 
>  
> 
> On 29/07/2015 15:58, Michael Black wrote:
> Hi Mike,
> 
> Actually he's running a Flex 3000 and an 8-core machine.
> 
> Interesting, is it possible he has set CPU affinity. Maybe it was just 
> that all the JT9 decodes took longer than the longest JT65 decode but 
> that is fairly unusual.
> 
> 
> 
> 
> JTAlert doesn't currently allow setting the IP address so it's not 
> multi-cast.  I'll see if about getting that done though.
> 
> It's not quite as simple as setting the address, a multicast server 
> has to join the group as well.
> 
> 
> 
> 
> Side-by-side is good idea.
> 
> And a sequence number does take a step towards TCP but is still not a 
> bad idea so you can at least detect dropped packets.  People could be 
> using this now and not know they are missing decodes.
> 
> Datagrams can also be delivered out of order so it gets complicated fast.
> Anyway on a loopback connector neither out of order delivery nor 
> dropped datagrams should happen unless the receiver is really slow 
> about responding to received datagrams.
> 
> I would really prefer to see confirmation that datagrams are really 
> going missing by using message_aggregator before we start changing code.
> 
> 
> 
> 
> 73
> 
> Mike W9MDB
> 
> 73
> Bill
> G4WJS.
> 
> 
> 
> 
>  
> 
> From: Bill Somerville [mailto:[email protected]]
> Sent: Wednesday, July 29, 2015 9:47 AM
> To: [email protected]
> Subject: Re: [wsjt-devel] UDP messages dropped
> 
>  
> 
> On 29/07/2015 15:37, Michael Black wrote:
> Hi Mike,
> 
> Testing JTAlert 2.6.10 beta with WSJTX 5728 on a friend's setup.
> 
> 20M came alive yesterday and we observed JTAlert missing, for example, 
> ALL of the JT9 decodes (which were bunched at the end of his Band 
> Activity window).
> 
> If all the JT9 decodes are together I assume the CPU in use has only 
> one or two cores as the MT decoding doesn't seem to be active.
> 
> 
> 
> 
> 
> It was random.frequently all the JT9's were missed, and sometimes some 
> random others, sometimes all of them were OK.
> 
> So it appears to be some timing issue.
> 
>  
> 
> UDP is also known as "Unreliable Data Protocol" but it shouldn't drop 
> packets very frequently (if at all) on a local network connection.
> 
> Can you verify the same behaviour using message_aggregator? I don't 
> know if JTAlert is multicast compliant but if it is you could use 
> 239.255.0.1 as an address and have JTAlert and message_aggregator both 
> receiving the messages in parallel for a double verification. Dropped 
> datagrams on a loopback connector are very unlikely.
> 
> 
> 
> 
> 
>  
> 
> So.to help trace this down can we add a 1-byte rolling sequence number 
> to the Decode message?  That would help the client detect any dropped
packets.
> 
> That is missing the point of UDP!
> 
> 
> 
> 
> 
>  
> 
> Is the access to the socket write from WSJT-X multi-threaded between 
> JT65 and JT9?  Not sure what behavior might in that case.
> 
> The UDP messages are sent from the main GUI thread, there are no MT 
> implications.
> 
> 
> 
> 
> 
>  
> 
> 73
> 
> Mike W9MDB
> 
> 73
> Bill
> G4WJS.
> 
>  
> 
> 
> 
> 
> ----------------------------------------------------------------------
> --------
> 
> 
> 
> _______________________________________________
> wsjt-devel mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/wsjt-devel
> 

----------------------------------------------------------------------------
--
_______________________________________________
wsjt-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/wsjt-devel


------------------------------------------------------------------------------
_______________________________________________
wsjt-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/wsjt-devel

Reply via email to