LotW Backlog continues to grow ...
- LotW backlog:
Upload Processed Backlog
2012-11-28 22:32 2012-12-05 02:08 6 days 05 Hr 36 min
2012-11-29 18:38 2012-12-06 05:10 6 days 10 hr 32 min
2012-11-30 00:58 2012-12-06 18:24 6 days 17 hr 26 min
2012-11-30 17:04 2012-12-07 17:28 7 days 0 hr 24 min
LotW has now broken *one week* in delay. As of last Friday LotW was
receiving 50% more uploads than it was processing each day.
Although spot checks of the LotW statistics (increase in the number of
QSO records in a timed 10 or 30 second interval) seem to indicate that
LotW is processing QSOs at a faster rate - perhaps as many as 3600 Q/hr
- the system still appears to be critically overloaded to a degree not
resolvable by the simple storage system upgrade ARRL have announced is
I do not know what hardware is being used for Logbook but it appears
that the system is compute bound and should be completely redesigned
for operation on a multi-processor ("blade") server where uploads
could be processed in parallel to enter the data into the database
as quickly as possible without concern for "matching." Once the input
load dropped to a sustainable level, some processors could then switch
to QSL matching functions working down the list of "new" entries.
... Joe, W4TV
- On Tue, Dec 11, 2012 at 2:33 AM, Robert Chudek - K0RC <k0rc@...> wrote:
It is certainly a sign of competence and design skills when you realize the LoTW system was deployed on SAN technology 10+ years ago. That was leading edge architecture at the time, and unlikely to be found outside of corporate server farms or large data centers.
For anyone interested in considerations the regarding the marriage of SANs and Database architecture, here's an article describing the issues facing system designers. It's a pretty decent primer on some basic database design too.
73 de Bob - KØRC in MN
Thanks for the link, Bob. Enterprise decisions concerning SSDs are the same as I went through when deciding to use them. 8*)Speaking of enterprise...do you know of any studies comparing MTBF for consumer vs enterprise SSDs?
Ken - K4XL
BoatAnchor Manual Archive
BAMA - http://bama.edebris.com