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Hi John, re: > When you say smaller or larger products, can you tell me if that means a > different > transfer method via TCP? Or, simply just a matter of shear volume? There is no difference in the LDM transfer method. To me, at least, the product size could be important if there are a lot of re-transmits (for whatever reason) as it would take longer for a product to be received, and the transfer of products for each/every ldmd connection are serialized. Speaking of serialization, one approach to mitigating the receipt latency of high volume feeds is to split a single ".*" REQUEST into multiple, disjoint REQUESTs the union of which is the full set of data. For feeds like NIMAGE, this is very easy as there are subsets that are easily identifiable (e.g., GOES16 is part of each NIMAGE Product ID for GOES-16 imagery and GOES17 is part of each NIMAGE Product ID for GOES-17 imagery; there are 4 distinct coverages of CONUS, FullDisk, Mesoscale-1, and Mesoscale-2; etc.; etc). Feeds like NGRID, on the other hand are difficult to split into disjoint subsets as their Product IDs don't easily lend themselves to splitting. The best example for a feed that is easy to split is CONDUIT since each product sent in the CONDUIT feed has a sequence number as the last element of the Product ID. This allows for easy split into 2, 5, 10, etc. The same notion of splitting high volume feeds into subsets also works for the case where there is some form of bandwidth limiting on a per connection basis but the overall available bandwidth is not limited. re: > When I watch the "ldmadmin watch" I see numerous product entries for NEXRAD > and > IDS|DDSPLUS and very few entries for NGRID, NIMAGE, and NOTHER. Correct. The reason for this is that the latencies for the NGRID, NIMAGE and NOTHER products is large enough that they exceed the <max-latency></max-latency> setting in the LDM registry, ~ldm/etc/registry.xml. One can increase the <max-latency> value over its 3600s (1 hour) default, but this does not guarantee that the upstream that is sending the product will have a large enough LDM queue so that the product will still be in the queue after whatever value the <max-latency> is increased to. re: > Note, when I run "iptraf-ng" or a wireshark capture, I do see about 1/3 to 1/4 > the amount of traffic reaching a server during the "traffic shaping" period > compared to normal function times. OK, this is consistent with what my thinking was to begin with. I say this because other sites being fed the same feed(s) as the ones that are being REQUESTed by mammatus were showing near-zero latencies at the same time that mammatus was reporting latencies that were greater than an hour. If you recall, I noted that in one of my previous emails. By the way, you never did answer my question about why rime only has a 100 Mbps connection: is it the Ethernet interface(s) on rime, or is it that you are connected to a 100 Mbps port on a switch? One last comment: We recommend keeping a REQUEST for IDS|DDPLUS in the LDM configurations on both mammatus and meso-file1. The reason is that low latencies seen for products in this feed when compared to latencies seen in higher volume feeds is a good rule-of-thumb indicator for intentional/unintentional shaping of feeds, and its volume is low enough that it will not have much, if any, affect on the max residency time of products in the local LDM queue. Cheers, Tom -- **************************************************************************** Unidata User Support UCAR Unidata Program (303) 497-8642 P.O. Box 3000 address@hidden Boulder, CO 80307 ---------------------------------------------------------------------------- Unidata HomePage http://www.unidata.ucar.edu **************************************************************************** Ticket Details =================== Ticket ID: GUQ-669331 Department: Support LDM Priority: Normal Status: Closed =================== NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.