Re: LDM latency

> I'm still struggling to get to the cause of my latency issues, it seems to 
> be something different every day. Currently my IDS data is up to date but 
> the HDS is falling farther and farther behind (see below). Is your HDS 
> coming in without latency? Thanks for checking, this will help me isolate 
> my problem. I would failover to sunny89 at UW but, every time I try that 
> my product que gets corrupted. Also, could you tell me which LDM version 
> you are running?

Mike:

I'm not sure what LDM version I'm running.  Anne Wilson installed it on 
aeolus for me in December of 2001.  (We have only one system administrator 
in my division to support 50+ networked unix hosts.  While he'd "like to 
help", he says he doesn't have the time.)

I've checked the HDS files coming in several times since your message got 
here yesterday.  The latencies here range from very short to ridiculously 
long and everything in between.  I don't spend as much time watching this 
as I should, but I have formed a suspicion based on what little time I 
could devote to monitoring the data stream.

The number of NNEXRAD files I see seems to have increased by an order of 
magnitude over the near term.  Lately, I can run "ldmadmin watch" (which I 
do from time to time) and it seems as though I get 10 or 15 NNEXRAD 
products for every one DDPLUS or HDS product.  At other times it appears to 
be about even.  One NNEXRAD for one of anything else.

I'm speculating that the NNEXRAD volume my be overwhelming the ability of 
my somewhat elderly DEC5000 to handle the datastream.  Also, my queue size 
is set at 750,000,000.  I've considered increasing that to see if 
throughput might improve.  (Support: is it likely this would improve 
throughput and latencies?)

Larry


     ---===---=-=-=-=-=-=-=-=-=-=-=====[\/]=====-=-=-=-=-=-=-=-=-=-=---===---
   -----===(*  Climate's what we expect, but weather's what we 
get.  *)===-----
  Larry Riddle : Climate Research Division : Scripps Institution of 
Oceanography
      University of California, San Diego : La Jolla, California  92093-0224
      Phone: (858) 534-1869 : Fax: (858) 534-8561 : E-Mail: address@hidden