Status Report: March 2014 - September 2014

Steve Emmerson, Mike Schmidt, Tom Yoksas

Strategic Focus Areas

The LDM group's work supports the following Unidata funding proposal focus areas:

  1. Enable widespread, efficient access to geoscience data
    The LDM powers the Unidata Internet Data Distribution (IDD) system.
  2. Provide cyberinfrastructure leadership in data discovery, access, and use
    The LDM allows sites to move data in their own environments.
  3. Build, support, and advocate for the diverse geoscience community
    The LDM is used by US universities and by entities throughout the world.

Highlights Since the Last Status Report

Multicast-capable LDM-7

Work on the multicast sending and receiving components of LDM-7 are about 80% completed. The components still need to be integrated into the rest of the LDM. LDM-7 has the potential to greatly reduce the bandwidth used by the UPC to distribute data via the Internet Data Distribution (IDD) system.

Added ability to disable anti-denial-of-service feature

This was done in response to a difficulty in using the LDM by NASA's Johnson Space Center. The anti-DOS feature should only be disabled by sites that know and trust all downstream LDM-s that can feed from it.

LDM now using c99(1) standard

Had to happen sometime. The LDM code is deliberately kept back from the latest standards in order to accomodate older environments.

Adapting to new NOAAPORT SBN broadcast

Two new data channels were added and work continues on enhancing ingestion of the new NOAAPORT broadcast.

Added support for the syslog-ng(8) system logging daemon

The LDM installation process traditionally expected that the system logging daemon was syslog(8) or rsyslog(8). Debian-based Linux systems (e.g., Ubuntu) use syslog-ng(8) instead. This would break the LDM installation until the user reverted to a syslog(8) variant.

Increased assumed mean product-size from 4096 bytes to 51,000 bytes

This parameter is used to compute the default maximum number of data-products that the LDM product-queue can hold -- given the maximum size for the queue in bytes. The smaller number was correct for 1996 -- but not now.

Planned Activities

Ongoing Activities

We plan to continue the following activies:

  • Support LDM users
    • Email, phone, etc.
    • Training workshops
  • Work on multicast-capable LDM-7
  • Incrementally improve the LDM as necessary
  • Incorporate additional AWIPS-II-related changes into the LDM
  • Update table-driven decoding of GRIB products as necessary