Re: [ldm-users] NEXRAD2 Latency/Fragmented Data?


I have received the same advice from Steve and Tom. With that level of
insistence, I'm considering the information golden. AND, it does work
better, through objective notice. What happened to change things is that
the new state files associated with the pqact statements have to be unique
or you'll snag a lot of repeat data when you restart (although I could be
garbling this; caffeine deficient). By creating softlinks to the same file,
as Daryl illustrated, the statefile is created for each instance, and the
appropriate instance of pqact is forked as a new scan comes in.


On Tue, Jul 31, 2012 at 8:42 AM, Gilbert Sebenste <
sebenste@xxxxxxxxxxxxxxxxxxxxx> wrote:

> On Mon, 30 Jul 2012, we looked up in the sky. Did we see a bird? A plane?
> Nah, it's Super Daryl Herzmann, who wrote:
>  Gilbert,
>  Steve Emmerson kindly informed me that this is not quite the proper thing
>> to do.  Each pqact process should have an unique filename associated with
>> it for when it writes state information to disk.  The files can be simple
>> sym links and it will 'trick' LDM just fine.  So the recommendation is to
>> simply:
>> cd /home/ldm/etc
>> ln -s pqact.gempak_craft pqact.gempak_craft.1
>> ln -s pqact.gempak_craft pqact.gempak_craft.2
>> ln -s pqact.gempak_craft pqact.gempak_craft.3
>> ...etc...
>> Then in ldmd.conf
>> exec    "/home/ldm/bin/pqact -f NEXRAD2 -p BZIP2/P[A-Z]
>> /home/ldm/etc/pqact.gempak_**craft.1"
> Hmmm. I thought the issue was rpc not being able to keep up with such a
> high data feed rate, not I/O.
>  Also note with the above, that you would be missing the radars starting
>> with D,N, and R :)  Here's what I use:
>> exec    "pqact -p BZIP2/K[A-D] -f CRAFT /home/ldm/etc/pqact.CRAFT"
>> exec    "pqact -p BZIP2/K[E-H] -f CRAFT /home/ldm/etc/pqact.CRAFT2"
>> exec    "pqact -p BZIP2/K[I-K] -f CRAFT /home/ldm/etc/pqact.CRAFT3"
>> exec    "pqact -p BZIP2/K[L-O] -f CRAFT /home/ldm/etc/pqact.CRAFT4"
>> exec    "pqact -p BZIP2/K[P-R] -f CRAFT /home/ldm/etc/pqact.CRAFT5"
>> exec    "pqact -p BZIP2/K[S-Z] -f CRAFT /home/ldm/etc/pqact.CRAFT6"
>> exec    "pqact -p BZIP2/[A-J] -f CRAFT /home/ldm/etc/pqact.CRAFT7"
>> exec    "pqact -p BZIP2/[L-Z] -f CRAFT /home/ldm/etc/pqact.CRAFT8"
> Yeah, I cut a few out for simplicity. Interesting, though...Steve, can you
> comment more about this to clarify why this should be done?
> ****************************************************************
> *******************
> Gilbert Sebenste
>  ********
> (My opinions only!)                                                  ******
> Staff Meteorologist, Northern Illinois University                      ****
> E-mail: sebenste@xxxxxxxxxxxxxxxxxxxxx
>  ***
> web:                                      **
> Twitter: 
>                      **
> Facebook: 
>                       *
> ****************************************************************
> *******************
> ______________________________**_________________
> ldm-users mailing list
> ldm-users@xxxxxxxxxxxxxxxx
> For list information or to unsubscribe,  visit:
  • 2012 messages navigation, sorted by:
    1. Thread
    2. Subject
    3. Author
    4. Date
    5. ↑ Table Of Contents
  • Search the ldm-users archives: