All,
A test of the AWIPS Network Control Facility (NCF) backup servers has
been scheduled by the NWS for 15:15 UTC this coming Wednesday, May 19.
The announcement of the test, broadcast in NOAAPort and relayed to
users subscribed to our nws-changes@xxxxxxxxxxxxxxxx email list, is
included at the end of this email for your review.
Those of you subscribed to this list who are operating NOAAPort ingest
systems using the Unidata 'noaaport' package will be aware that the
past several tests of the NCF backup servers have resulted in
"corruption" of some nwstg2 GRIB2 messages (typically multiple GRIB2
messages were sent as a single product). Some of the products have
been seen to cause 'noaaport's processing routine 'readnoaaport' to
exit with error, and this, in turn has led to the LDM running on the
ingest machine exiting. The NOAAPort ingest machines run by the
UPC have been instrumented to monitor data ingest, and restart the
LDM upon unintended exit.
Code modifications and GRIB2 table updates made by Steve Chiswell
(DOE/Savannah River National Laboratory) have been included in a new,
** TEST ** release of our 'noaaport' ingest package, noaaport-1.4.0.tar.gz.
This release is available by FTP as follows:
machine: ftp.unidata.ucar.edu
user: anonymous
pass: <your full email address>
directory: pub/noaaport
file: noaaport-1.4.0.tar.gz
Please be aware of the following changes to the code and their possible
impact on you and/or your users:
1) product bulletin sizes are compared to decoded GRIB lengths to
trap and prevent overruns (the cause of problems see in the current
release)
2) SDUS8 products are being moved from HDS to NEXRAD3
This allows future dual-polarization products to be included in the
NEXRAD3 datastream, and it will cause the SDUS DPA products to move
from the HDS to NEXRAD3 datafeeds.
Implication:
You, and/or users who feed from you may have LDM pattern-action file
actions that process DPA products from HDS. After the new code is
up and running, sites using the DPA products will need to modify
their setups to process the DPA products from the NEXRAD3 feed.
3) the g2clib library bundled with 'noaaport' was updated to version
1.2.0 to add the WAFS (thinned grids) coming in the near future
4) GRIB2 decoding tables were updated for new levels and parameters
5) an argument was added to 'dvbs_multicast' to specify the multicast
interface (in case a static route is needed instead of the default
route)
6) readnoaaport-1.4, like its predecessors, uses LDM configuration
files for its build. readnoaaport-1.4 has been tested with
LDM-6.8.x only. It is not expected to work with very old
LDM installations, and it is known to NOT build on systems
where the new test LDM-6.9.x is installed.
The build setup for noaaport-1.4 will need to be updated to
work with LDM-6.9.x. Until a new release of noaaport is made,
you are advised to continue using LDM-6.8.1.
NB:
Because of 2) above, we are requesting that sites running NOAAport
ingest systems whose output is fed into the IDD wait until the late
afternoon or evening of Tuesday, May 18 to transition to the new code.
On Monday, May 14 an email will be sent to the ldm-users@xxxxxxxxxxxxxxxx
email list notifying IDD participants of the impending change and
advising them of the action(s) that they will need to take to minimize
impacts to their data processing.
Please relay this message to folks you know are running the Unidata
NOAAPort ingest package but not subscribed to this list.
Please direct questions/comments to support-noaaport@xxxxxxxxxxxxxxxx.
Cheers,
Tom Yoksas
Unidata User Support
The following is the NWS announcement of the NCF backup test:
196
NOUS72 KNCF 141548
ADMNCF
.
PLEASE PASS TO THE MIC/HIC, SOO, ESA, ITO AND AFP:
.
THERE WILL BE AN OPERATIONAL TEST OF THE AWIPS
NETWORK CONTROL FACILITY (NCF) BACKUP SERVERS.
NCF SERVER OPERATIONS WILL BE SWITCHED FROM THE
PRIMARY AWIPS NCF (ANCF) IN SILVER SPRING, MD TO THE
BACKUP NCF (BNCF) AT FAIRMONT, WV. THE SWITCH IS
SCHEDULED FOR WEDNESDAY, 19 MAY AT 1515 UTC.
OPERATIONS WILL BE SWITCHED BACK TO THE PRIMARY
NCF ON THURSDAY, 20 MAY AT 1515 UTC. THE SWITCH
WILL NOT BE DONE ON A CRITICAL WEATHER DAY, OR
IF THERE ARE OTHER SIGNIFICANT OPERATIONAL ISSUES
WARRANTING POSTPONEMENT.
.
ALL ANCF MESSAGE DISTRIBUTION WILL BE REPOINTED
TO THE BNCF. THE SWITCH TO THE BNCF WILL BEGIN
AT 1515 UTC AND WILL TAKE ABOUT 20 MINUTES. DATA
WILL QUEUE WHILE THE SWITCH IS IN PROGRESS AND
WILL BE SENT ONCE THE SWITCH IS COMPLETE. THIS
WILL AFFECT DATA ORIGINATING AT NWS FIELD OFFICES
AND NATIONAL CENTERS ON THE AWIPS NETWORK
INCLUDING RADAR DATA.
.
REPOINTING OF OPERATIONS BACK TO THE ANCF WILL
ALSO TAKE ABOUT 20 MINUTES DURING WHICH DATA
WILL BE QUEUED. QUEUED DATA WILL BE SENT WHEN
THE REPOINTING IS COMPLETE.
.
NCF
--
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