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[LDM #GUQ-669331]: Both Radar and Satellite feeds stopped downloading abruptly

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  • Subject: [LDM #GUQ-669331]: Both Radar and Satellite feeds stopped downloading abruptly
  • Date: Thu, 29 Aug 2019 10:25:11 -0600
John,

> Sorry, I was only wondering if our outbound traffic was being throttled as 
> well.
> 
> From looking at the LDM traffic in Wireshark it looks to me that each packet 
> containing data is acknowledged immediately by my server prior to the next 
> packet being sent by your server.  If that's the case, like normal TCP 
> traffic, the only way throttling would make sense to me is if our border 
> firewall was buffering (i.e. holding) traffic for a period of time before 
> sending it along.  Hard to believe the device would do that, especially for 
> an hour.

It doesn't need to buffer. It likely simply discards incoming TCP packets -- 
simulating network congestion -- and relies on TCP's congestion-control 
mechanism. From the sender's perspective, it just seems like a slow network.

> I just can't see how throttling is an issue here if I'm seeing normal looking 
> traffic during that time.
> 
> At what point in the LDM packet ingest process is "ldmadmin watch" getting 
> it's information?   I don't understand how "ldmadmin watch" isn't outputting 
> anything with a ton of network traffic flowing between our server and yours.

The "ldmadmin watch" command executes the pqutil(1) program, which looks at the 
young-end of the product-queue for newly-inserted products. If no products are 
inserted, then nothing is printed.

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: GUQ-669331
Department: Support LDM
Priority: Normal
Status: Closed
===================
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