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[Datastream #QQX-689346]: Level 2 data packets arriving out of sequence

Hi there,

I'm writing to let you know that several actions have been taken on our end 
that may alleviate this condition.  Nothing drastic, mostly just giving a few 
LDMs a restart and similar.  But I'm seeing signs from rtstats that the NEXRAD2 
feed has improved.  Are your NEXRAD2 feeds looking better for you now?


While investigating, and frankly while becoming more familiar with NEXRAD2 
dataflow myself, I found that these packets are not and have never been 
guaranteed to be in order.  I think typically it makes sense that they would 
be, but that was never assured.  As such it is the responsibility of downstream 
sites to work with the data the way that it comes in, if out of order packets 
are a problem for your workflow then the workflow may need to change.  The 
reason why they might occasionally be out of order is our redundancy of 
requesting from multiple upstream hosts; sometimes one may ship data sooner 
than the other and there you go.

A while back the Python group here wrote some utilities to help manage 
accepting NEXRAD2 data, that repo contains a few other things including 
goes-restitch.py for GOES-R data.  The repo name is ldm-alchemy and is 
available here: https://github.com/Unidata/ldm-alchemy.  If you have any 
questions regarding those utilities, address@hidden would be the better inbox 
to reach out to.


We will continue to monitor the IDD feeds, NEXRAD2 a little closer, and there 
may be one or two more minor changes that could help improve things further.


Best,
-Mike

Ticket Details
===================
Ticket ID: QQX-689346
Department: Support Datastream
Priority: Normal
Status: Open
===================
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