Chiz can correct me if I'm really mistaken, but the later versions of
LDM ignore PRIMARY||ALTERNATE if you have two *identical* requests and
try to get the lowest latency one. That they bounce back and forth
doesn't imply you get the whole backlogged queue, however, as in 6.6.x a
file's written that says where it's got current data to, and upstreams
are advised of this, and should send data from that point on, rather
than the entire contents of the ldm.pq...
gerry
Daryl Herzmann wrote:
Hi Tyler,
Do your log files show your LDM switching feeds when data starts flowing
again?
I can't seem to fully resolve it, but the newer LDM seems to get
confused when you have multiple hosts feeding you the same data types
without specifying PRIMARY ALTERNATE. I dunno, I'm running into all
sorts of strange LDM things lately :(
daryl
On Mon, 2 Apr 2007, Tyler Allison wrote:
[for ldm-6.6.0 and ldm-6.6.2]
If I use the following feed pattern [upstream = idd@wisc and
bigbird@tamu]:
request WMO
"((WF|WO|WU|WR|WW|WG|AC|NW)US)|^S[AP]|^S[NS]|^WT(PZ|PN|PA|NT)|(^S[IMN]V[^GINS])|(^S[IMN]W[^KZ])|(^S(HV|HXX|S[^X]))|(^SX(VD|V.50|US(2[0-3]|08|40|82|86)))|(^Y[HO]XX84)|^A
CUS11|/p(FTM|FWDDY)" upstream.server.edu
the data seems to flow down to me in "chunks". What I mean by this is
that
is when I run 'ldmadmin watch' I see no data for between 4 and 10
minutes.
Then all of a sudden the last 4-10 minutes worth of data comes down
within
a 3 second period. It then holds again...and 4-10 minutes later another
payload of data comes down...etc...etc.
If the *ONLY* thing I change is the feed pattern to:
request WMO ".*" upstream.server.edu
The data feed runs normal.
I'm confused! I, and the upstream, have bandwidth to burn so I'm leaving
the feed as ".*"...my pattern was attempting to conserve bandwidth for
the
upstream providers but it seems I did more harm than good.
I havent totally verified this issue but it seems to be the culprit. Can
anybody confirm?
-Tyler
/**
* Daryl Herzmann, RHCE
* Program Assistant -- Iowa Environmental Mesonet
* http://mesonet.agron.iastate.edu
*/
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