Peter Shawhan, Carlos, Jim, Dave:

FRS4412, WP5740

Summary of problem, IERS (international earth rotation and reference systems) web page which announces future leap seconds addtions to UTC (called the Bulletin C page http://www.iers.org/SharedDocs/News/EN/BulletinC.html) was being accessed by LHO CDS several times per second. 

We had two problems: h1hwinj1 machine accessing the web page every 10 seconds, h1guardian0 machine accessing the web page on average several times per second. In both cases it was a non-bash-shell process calling the tconvert program.

tcleaps.txt data file

A new location outside of the apps area is now used to hold the tcleaps.txt datafile which provides tconvert with the history of leap seconds. The new location is /ligo/data/tcleaps/tcleaps.txt. This directory is referenced by the environment variable TCLEAPSDIR.

h1hwinj1:

Fix was to change the standard environment as defined by the files /ligo/cdscfg/lho/h1/stddir_linux.sh and stdrc_linux.sh. Rebooted h1hwinj1 machine.

h1guardian0:

Guardian nodes call tconvert via the cdsutils-gpstime utility. Fix was to change /ligo/apps/linux-x86_64/cdsutils/etc/cdsutils-user-env.sh. Rebooted h1guardian0 machine.

Verification:

Before and after the changes we ran tcpdump on the main CDS NAT router to verify web access to the Bulletin C page went from several per second to zero. During normal operation, this web page should only be accessed twice a year.