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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
LDM Status Report
by
Steve Emmerson
2003-02-18
The latest LDM is called LDM-6.
LDM-6 has much better performance than its predecessor, LDM-5, due to the use of non-blocking RPC calls and better connection strategies. In a test sending 200 kilobyte products over a high-bandwidth, high-latency network from the UPC to Belem, Brazil, LDM-6 had 8.4 times better throughput than LDM-5.
LDM-6 is completly backward-compatible with the previous LDM-5: it can both send to and receive from an LDM-5 with performance that is equal to or better than an LDM-5's.
A new program by Steve Chiswell has been added. Named rtstats, this program supports the near real-time display of product latencies by the UPC and has allowed Yoksas, Chiswell, and Emmerson to verify and validate the performance of LDM-6.
LDM-6 has been tested on 12 systems -- including thelma.ucar.edu, motherlode.ucar.edu, papagayo.unl.edu, marzipan.atmos.washington.edu, and atm.geo.nsf.gov.
We are releasing it now.