Re: LoTW's response to "Sync LoTW QSOs" and "Sync LoTW QSLs" functions

Mike Flowers

Also, those contemplating the mysteries of LotW processing times should be aware that recently there have been software and database maintenance activities happening there.   Sometimes processing takes longer and sometimes batch processing must be deferred for some period of time.


- 73 and good DX de Mike, K6MKF, NCDXC Secretary


From: <> On Behalf Of Hasan Schiers N0AN
Sent: Tuesday, March 31, 2020 14:50
Subject: Re: [DXLab] LoTW's response to "Sync LoTW QSOs" and "Sync LoTW QSLs" functions


Interesting. Mine just sat there (they looked like they had uploaded fine, and I'm sure they did as no errors came back from DXK.

The strange thing is they did not show up here:



For well over a day after I told DXK to batch upload them.


I didn't do anything over the next 36 hours except check back on the site. This morning, they were there.


The new qsos from this morning (not the 'stalled ones') , uploaded in a batch this morning just fine, but took a few minutes to show up as usual.


So, another mystery, a not at all important one.

73, N0AN




On Tue, Mar 31, 2020 at 4:41 PM Dave AA6YQ <aa6yq@...> wrote:

+ AA6YQ comments below

Just another data point. After the contest finished, I did a small batch upload for qsos after 03/28/2020....they did not show up on the ARRL web site until this morning (last checked late afternoon yesterday)  For over two days, my last qso shown was 03/28/2020, when I had had several qsos in the period from 03/28/2020 to 03/30/2020

DXK uploaded them just fine (no errors), so I assume LoTW reported to DXK that it received them and the delay at showing them on the ARRL web site was the result of the contest.

My guess is that my DXK batch upload (of about 8 qsos), went to the back of a long line of large batch uploads from the contest. At least that's my theory, and I'm sticking to it.  😎

Of further interest: KB7IJ was uploading the same qsos in real time (not batch like me)...his all showed up within a minute or so of the end of each of our qsos. So it looks like priority was given to real time uploads.

+ That’s not correct. In the middle of a major contest,  no one is submitting their contest logs, so if anything,  the "load" on the LoTW server is lower than usual. Any LoTW submissions made during such a contest -- in real time, or in a batch -- will likely be processed quickly.

+ As I posted yesterday in the ARRL-LoTW group, Inspecting the ingestion queue status at


+ shows that the processing delay was less than 2 minutes at 15Z, but then began rising to a peak of nearly 3 hours at 21Z. 

+ By 00Z, processing delay was almost down to an hour; my guess was that it would be back to its 1-2 minute non-contest steady state by 02Z, but I didn't check.


                Dave, AA6YQ

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