messages failing - message lockup


Arnold Harding - KQ6DI
 

Lynn,

I completely agree with the specification and the intent of getting the messages through.  In fact APRS messaging during an event has helped us considerably, and I do want to know if a message was not received so we do get that 100% of the message.

That said, there is something going on in APRSISCE when station A sends a message to station B, but station B doesn't acknowledge, and the 6 attempts fail.  It doesn't seem to recover as intended.  At least that's what we see.

I'll investigate what I'm seeing more, but I have seen some very odd things where the only way to recover messaging operation is to Abort the message after the Final retry (or restart the program).  The part about double-click the message indicator in the right corner also seems to be a not-obvious feature.  It might be documented, but there are so many good features in APRSISCE that I haven't found them all yet.

This weekend I believe 7 of us are using APRSISCE while supporting a bicycle race (not a ride), and messaging gets heavy use, as well as 8 trackers.

Arnold, KQ6DI

On May 20, 2019 at 5:41 PM "'Lynn W Deffenbaugh (Mr)' kj4erj@... [aprsisce]" <aprsisce@...> wrote:

 

 

From the aprs101.pdf specification:

 

The sending station will repeatedly send the message until it
receives an acknowledgement, or it is canceled, or it times out.

 

It doesn't say what the sending station is supposed to do once any of these conditions is met.  APRSISCE/32 chooses to keep the message until the operator manually cancels it allowing the subsequent messages to be sent.  These pending messages will currently be dropped if APRSISCE/32 is restarted.  Some other APRS clients would keep the messages across restarts causing some messages to be retried days, weeks, months, or even years after they originally timed out.

This is by design, and the design was chosen to ensure that messages are sent in the order they were entered and that no messages are skipped unless an operator asks them to be skipped.   This is really important with the way I do long message splits into APRS-sized messages and queue them sequentially.  If one segment isn't ack'd, the other segments will wait for operator intervention.

The retry logic of APRSIS32 is described on the Wiki at:

http://aprsisce.wikidot.com/message-retries

You have it mostly right, except that APRSISCE/32 will automatically start a second round of retries if a packet is received from a station that has already exhausted the first set of retries.  If the second set is also exhausted, the state of that message will go to "FINAL Retry" (as opposed to "Final Retry".

If you have pending messages that are retrying or have timed out, you should have a yellow message indicator in the upper right corner.  If you double-click that indicator, you will be shown the message that's holding up the works and be given an opportunity to deal with it.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

PS.  Feel free to forward this on to anyone that might need to know it.  I've copied the APRSISCE Yahoo group in compliance with my theory that for every question asked, there are likely 5 or more people interested in the answer.

On 5/20/2019 6:07 PM, ARNOLD HARDING wrote:

Lynn,

This is a snip of a message I sent to a couple APRS operators.  We use messaging during an event this weekend, and we have had unusual message lock-ups, and I think I found the issue.  Pending, but "tried-out" messages prevent any additional messages from being sent to that station, EXCEPT Ack's and automatic messages will go.  With that said, The remainder of this message may explain more of what we've seen and the work-around.  Maybe this is intentional, but it sure got us wondering what was going on until I figured this out.

Arnold, KQ6DI


I think I found a minor bug in APRSIS that may be the cause of your station failing during the day.  I have confirmed this with John WB6ETY, that this does happen.

When a message is sent, there are six (6) attempts at sending the message before it is marked as failed.  The six attempts have pauses between them, and the pauses get longer as the retry count goes up.  But, when the message is finally marked as failed, something gets left behind saying pending, and no further messages can be sent to this station.  So...

In Messages (from the main screen), if Pending Messages is NOT grayed out, you can either abort the message, or select the callsign of the failed message and clear it out (Abort sending).

I can't explain it any better until you look.  I think there may be something where APRSIS isn't sending if the callsign is in this list.  So if something seems to be failing, check there, and maybe clear out the list.


We found that if a station failed to respond to a message, the sending station cannot send to that station until this is cleared or APRSIS is restarted.  However, ACKs will be sent to that station and automatic messages/replies such as "I'm away from the keyboard" will go to that "locked out" station.

One possible cause happens in the morning when the start line or summit attempts to send a message to the finish, but the finish is not set up, thus does not respond, and the message times-out (and is remaining...).

I may have not written this well, so ask questions if there are questions.  Please forward to the other SJ RACES APRS operators.

Arnold

KQ6DI

 


 


 


Greg D
 

ARNOLD HARDING kq6di@comcast.net [aprsisce] wrote:
The part about double-click the message indicator in the right corner
also seems to be a not-obvious feature. It might be documented, but
there are so many good features in APRSISCE that I haven't found them
all yet.
+1 to this. I never knew it was there either.

A better (or additional) place to put this would be under Messages, e.g.
Messages / Status or some such. Same subsequent dialog, but a more
obvious way to get to it. I know I've looked for such a feature there
in the past, and didn't find it.

Greg KO6TH


Michael Wright
 

I am involved with this same race, I setup on the summit of Mt Hamilton road and APRSISCE is the perfect tool as I can see where all the SAG and EMT vehicles are located. Also pass messages from Start line to top of mountain finish line along with other updates.

Arnold is looking into more of my situation where my station on the summit does great (I begin about 7 am) but about 9 am it will fail to transmit. My station doesn't beacon, nothing happens when I click Send. Even my SignalinkUSB doesn't respond. I can still receive (viewing station locations and getting messages) but as if the system is in "Receive Only" mode. I didn't have Ack checked. Then shortly after noontime, the system then returns to full functional use. But then by noontime our duties begin to wind down as all race participants pass the summit location.

This situation has happened two years in a row. I will do some tests later tonight and tomorrow.

Other than that, it is really cool, we get to see the various vehicles on the road and view messages. Much of what I learned of APRSISCE came from Arnold.

Mike K6MFW

--- aprsisce@yahoogroups.com wrote:

From: "ARNOLD HARDING

That said, there is something going on in APRSISCE when station A sends a message to station B, but station B doesn't acknowledge, and the 6 attempts fail. It doesn't seem to recover as intended. At least that's what we see..


Lynn Deffenbaugh
 

You haven't looked very hard.  When there are messages in the retry state, you should find Messages / Pending Messages is enabled.  Selecting it will do the same thing as double-clicking the yellow message box.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

On 5/21/2019 12:55 PM, Greg D ko6th.greg@gmail.com [aprsisce] wrote:
ARNOLD HARDING kq6di@comcast.net [aprsisce] wrote:
The part about double-click the message indicator in the right corner
also seems to be a not-obvious feature. It might be documented, but
there are so many good features in APRSISCE that I haven't found them
all yet.
+1 to this. I never knew it was there either.

A better (or additional) place to put this would be under Messages, e.g.
Messages / Status or some such. Same subsequent dialog, but a more
obvious way to get to it. I know I've looked for such a feature there
in the past, and didn't find it.

Greg KO6TH



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Posted by: Greg D <ko6th.greg@gmail.com>
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Yahoo Groups Links




Greg D
 

Hmmpf.  Well, thar it is.  I must not have had a stuck message at the time, or ??

Anyway, thanks for implementing my suggestion so quickly (in negative time, in fact!)  :)

Greg  KO6TH


'Lynn W Deffenbaugh (Mr)' kj4erj@... [aprsisce] wrote:

 

You haven't looked very hard.  When there are messages in the retry
state, you should find Messages / Pending Messages is enabled. 
Selecting it will do the same thing as double-clicking the yellow
message box.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

On 5/21/2019 12:55 PM, Greg D ko6th.greg@... [aprsisce] wrote:
> ARNOLD HARDING kq6di@... [aprsisce] wrote:
>> The part about double-click the message indicator in the right corner
>> also seems to be a not-obvious feature. It might be documented, but
>> there are so many good features in APRSISCE that I haven't found them
>> all yet.
> +1 to this. I never knew it was there either.
>
> A better (or additional) place to put this would be under Messages, e.g.
> Messages / Status or some such. Same subsequent dialog, but a more
> obvious way to get to it. I know I've looked for such a feature there
> in the past, and didn't find it.
>
> Greg KO6TH
>
>
>
> ------------------------------------
> Posted by: Greg D
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>



Lynn Deffenbaugh
 

Any time.  Glad I had the Delorean warmed up and parked out back for this one!

Actually, I think Pending Messages is always there, it's just disabled (grayed out) if there aren't any messages pending.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

On 5/21/2019 11:35 PM, Greg D ko6th.greg@... [aprsisce] wrote:
Hmmpf.  Well, thar it is.  I must not have had a stuck message at the time, or ??

Anyway, thanks for implementing my suggestion so quickly (in negative time, in fact!)  :)

Greg  KO6TH


'Lynn W Deffenbaugh (Mr)' kj4erj@... [aprsisce] wrote:
 

You haven't looked very hard.  When there are messages in the retry
state, you should find Messages / Pending Messages is enabled. 
Selecting it will do the same thing as double-clicking the yellow
message box.

Lynn (D) - KJ4ERJ - Author of APRSISCE for Windows Mobile and Win32

On 5/21/2019 12:55 PM, Greg D ko6th.greg@... [aprsisce] wrote:
> ARNOLD HARDING kq6di@... [aprsisce] wrote:
>> The part about double-click the message indicator in the right corner
>> also seems to be a not-obvious feature. It might be documented, but
>> there are so many good features in APRSISCE that I haven't found them
>> all yet.
> +1 to this. I never knew it was there either.
>
> A better (or additional) place to put this would be under Messages, e.g.
> Messages / Status or some such. Same subsequent dialog, but a more
> obvious way to get to it. I know I've looked for such a feature there
> in the past, and didn't find it.
>
> Greg KO6TH
>
>
>
> ------------------------------------
> Posted by: Greg D
> ------------------------------------
>
>
> ------------------------------------
>
> Yahoo Groups Links
>
>
>
>