Transcript XML Via SOAP & Local Degrib Applications Arthur A. Taylor ()

XML Via SOAP & Local Degrib Applications
Arthur A. Taylor ([email protected])
http://www.weather.gov/mdl/degrib/
Meteorological Development Laboratory
NWS NDFD Technical Workshop 2006
November 2, 2006
Why Use XML
Existing technology
• Extensible Markup Language is widely used (W3C
specification)
• De Facto standard for internet data exchange
• Infrastructure exists (validators, XML Schema, etc.)
Facilitates additional processing
• XML tools (XSLT, SAX, DOM) facilitate value added
applications
• Web application developers familiar with tools
• Schema precisely defines a language
Reaches new users
NWS NDFD Technical Workshop November 2, 2006
XML on the Move
WSDL
Data Broker
(UDDI)
WSDL
SOAP Request
SOAP Request
Data
Consumer
(Client)
Data
Provider
(Server)
Internet
SOAP Response
SOAP Response
Communicating Process
Discovery
Description
Messaging
Transport
(UDDI)
(WSDL/Schema)
(SOAP)
(HTTP)
NWS NDFD Technical Workshop November 2, 2006
Data
The SOAP server
The experimental (becoming operational Dec. 4) XML via
‘Simple Object Access Protocol’ server provided by
the NWS does the following:
Once an hour:
• Download the NDFD GRIB2 files
• Convert the GRIB2 files to data cubes
Upon request from the SOAP server:
• PHP code parses the request
• degrib_DP probes the data cubes
•
PHP code reformats it into XML
– Note: Sometime after Dec. 4, all formatting will be done by degrib
C code.
NWS NDFD Technical Workshop November 2, 2006
SOAP Server Lessons Learned
“If you build it, they will come”
NWS NDFD Technical Workshop November 2, 2006
Motivation
Why add DWML capability to degrib?
• Alleviate pressure on the XML server
– allows whole sale users to use the GRIB2 files to create XML,
using their own machines, for as many points and as often as
they desire.
• Speed up the server
– Migrates from a scripted language (PHP) to a compiled
language (C)
• Provide the source code for the logic behind DWML
– (c:\ndfd\degrib18\src\dwmllib\xmlparse.c)
• Encourage the use of DWML
NWS NDFD Technical Workshop November 2, 2006
Overview
To create NDFD DWML on a PC we need to
1. Download the NDFD GRIB2 to our PC
2. Probe the data at a given location
To enhance the speed of probing, we can also
3. Convert the data to a data cube
4. Probe the data cube at a given location
NWS NDFD Technical Workshop November 2, 2006
Attaining software
To get the degrib program, go to:
http://www.weather.gov/mdl/degrib/register.php
For MS-Windows, use “degrib-install.exe”
•
By default this installs to c:\ndfd\degrib18
For UNIX, use “degrib-src.tar.gz”
•
By default this expand to “/degrib”. To compile it:
– cd /degrib/src
– make –f makefile.* (* is replaced by your operating system)
NWS NDFD Technical Workshop November 2, 2006
Get Data
Option 1: Use “tkdegrib” or “tcldegrib web.tcl”
•
Advantage: In addition to downloading the data, it checks
for data corruption, by performing an inventory.
From a command Prompt:
• cd c:\ndfd\degrib18\bin
• tcldegrib web.tcl –dataSet ndfd –sector midatlan –day d17 –
variable all
Option 2: Use your own “URL get” program
• To determine the locations of the NDFD GRIB2 files:
1. http://www.weather.gov/mdl/degrib/dataloc.php
2. http://weather.noaa.gov/pub/SL.us008001/ST.opnl/DF.gr2/DC.
ndfd/AR.conus/
NWS NDFD Technical Workshop November 2, 2006
Probe Data
For more details on probe options, see:
•
•
http://www.weather.gov/mdl/degrib/tutorial.php#outputXML
http://www.weather.gov/mdl/degrib/txtview.php?file=degrib.t
xt&dir=base
From a command prompt
•
•
•
•
cd c:\ndfd\degrib18\data\ndfd\midatlan
..\..\..\bin\degrib . –P –pnt 38.98,-77.07 –XML 1 –geoData
c:\ndfd\degrib18\geodata
The –geoData option supplies a directory to look in for
information about the point’s timezone
For multiple points, either provide multiple –pnt options, or
use the “-pntFile” option
NWS NDFD Technical Workshop November 2, 2006
Flavors of DWML
•
-XML 1 (or time-series) creates the time series product
–
•
-XML 1 -Icon 1 will return just the icon information.
–
–
•
Requires: maxt, mint, temp, wspd, sky, wx
Formats: maxt, mint, sky, wx, icons
-XML 3 (or 12-hourly) is the 12 hour summary product
–
–
•
Requires: temp, wspd, sky, wx
Formats: icons
-XML 2 (or glance) is the glance product
–
–
•
User can choose to format any combination of the following: maxt,
mint, pop12, temp, wdir, wspd, td, sky, qpf, snow, wx, waveh, apt, rhm
Requires: maxt, mint, pop12, wdir, wspd, sky, wx
Formats: maxt, mint, pop12, wx, icons
-XML 4 (or 24-hourly) is the 24 hour summary product
–
–
Requires: maxt, mint, pop12, wdir, wspd, sky, wx
Formats: maxt, mint, pop12, wx, icons
NWS NDFD Technical Workshop November 2, 2006
Convert to data cube
The data cube consists of uncompressed data, which
allows faster access than the GRIB2 files
Method 1 (use c:\ndfd\degrib18\bin\MakeData.tcl):
•
•
•
cd c:\ndfd\degrib18\bin
tcldegrib MakeData.tcl c:\ndfd\degrib18\data\ndfd\midatlan
c:\ndfd\degrib18\cube\ndfd\midatlan
cd ..\cube\ndfd\midatlan
Method 2: Manual method
•
•
•
cd c:\ndfd\degrib18\data\ndfd\midatlan
..\..\..\bin\degrib maxt.bin –Data –Cube –Index maxt.ind –msg
all
Repeat for all GRIB (*.bin) files.
NWS NDFD Technical Workshop November 2, 2006
Probe the data cube
From a command prompt either:
•
•
..\..\..\bin\degrib . –DP –pnt 38.98,-77.07 –XML 1 –
geoData c:\ndfd\degrib18\geodata
..\..\..\bin\degrib_DP . –DP –pnt 38.98,-77.07 –XML 1
–geoData c:\ndfd\degrib18\geodata
-DP is for probing a data cube, while -P is for a
GRIB file
degrib_DP is compiled with just the data cube
probing code so it is smaller than degrib
NWS NDFD Technical Workshop November 2, 2006
Credits
I’d like to acknowledge:
• John Schattel for developing DWML
• Paul Hershberg for converting the PHP code to C.
NWS NDFD Technical Workshop November 2, 2006