[TIGGE #CED-782031]: does ldm server extract files locally

Dear MA Qiang,

> I found that we always miss some fields in the received cycles.
> Could you please tell me how to receive only the missing fields but not the 
> all cycle data in LDM, and give me some advice about how to check or ensure 
> the integrity of data?

The LDM system makes a "best effort" to deliver data in a
timely manner: problems with the network cause the oldest
data-products in the product-queue to be skipped
rather than causing the entire system to become excessively
backlogged.  This is a deliberate compromise between reliability
and delivery of current data.  The tradeoff can be moved in the
direction of more reliability and less timely delivery by increasing
the size of the product-queue and also increasing the maximum allowable
latency beyond its one-hour default value by using the "-m latency"
option of the "ldmadmin" script.  In any case, the "pqmon" utility
should be periodically executed to ensure that the oldest data-
product in a full product-queue is always older than the maximum
allowable latency.  Also, using a maximum allowable latency value that
is greater than the age of the oldest data-product in the upstream
product-queue is ineffective.

> Thank you!
> 
> Best regards,
> MA Qiang
> 
> National Meteorological Information Center
> 2008-06-05
> 
> Appendix:  The output of pqmon
> ldm01@tgn06 [ /usr/local/ldm01/tigge/data/outgoing ]
> $ pqmon -q /space/ldm_pq/ldm.pq
> Jun 05 01:32:09 pqmon NOTE: Starting Up (16279)
> Jun 05 01:32:09 pqmon NOTE: nprods nfree  nempty      nbytes  maxprods  
> maxfree  minempty    maxext  age
> Jun 05 01:32:09 pqmon NOTE: 115130  2055 3544924 14953609096    298672     
> 3802   3361434    147632 4797
> Jun 05 01:32:09 pqmon NOTE: Exiting
> 
> 
> -------------------------------------------------------------

Regards,
Steve Emmerson

Ticket Details
===================
Ticket ID: CED-782031
Department: Support IDD TIGGE
Priority: Normal
Status: Closed