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Hi Justin, re: > What is the appropriate ratio of main system memory to ldm queue size? It depends on what you are trying to do with your LDM installation. For instance, if you are trying to feed 150 downstream connections any/all of the data available in the IDD while keeping at least an hour's worth of data in the queue, then you should have at least an 8 GB queue. If you are just receiving data from one or more upstream nodes, then the size that your queue should be will be a function of the volume of data you are requesting, what processing you are attempting, and the speed of your machine (CPU and disk I/O subsystem). Most sites that are receiving _lots_ of data and relaying some data are using queues on the order of 2-4 GB. IDD leaf nodes, sites that are not relaying data and are requesting "reasonable" volumes are using queues anywhere between 400 MB to 1.5 GB. > Its looking like we might need a 6-8GB prodcut queue and have heard that a > ratio of 2:1 is what we should be using. Again, this will depend on whether or not you are relaying data to multiple downstream sites. > We are a bit concerned both at > the costs of all that memory plus the additional cost of finding a machine > which can support that much memory. We are using Sun SunFire V20Zs configured with either 12 or 16 GB of RAM in our toplevel IDD relay cluster. We sized the CPU spead (dual Opteron) and RAM with the aim of being able to feed up to 250 downstream connections from each of the 3 cluster data servers. We created this cluster to be able to service every IDD data request in the world. Other installations will settle for something less grandeous :-) > =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= > Justin R. Davis, Ph.D. > address@hidden > Post-Doctoral Research Associate > Civil and Coastal Engineering > 365 Weil Hall > University of Florida > Gainesville, FL 32611-6580 > 352-392-1436 x1528 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: FFC-953121 Department: Support IDD Priority: Normal Status: Closed