# Presentation: 271685

** **
** **

- Jordan C. Alpert/NCEP/EMC 	_[jordan.alpert@noaa.gov](mailto:jordan.alpert@noaa.gov)_
- Glenn Rutledge/NCDC

**where the nation’s climate and weather services begin**

- NOAA Operational Model Archive Distribution SystemNOMADS Toward an Operational Service Orientated Architecture

- EMC

- 5th GO-ESSP Earth Science Portal Workshop,   June 20, 2006 at Lawrence Livermore National Laboratory

- NCEP/Environmental Modeling Center

## NOMADS

*NOMADS*
*Web Page*

-   Completely
- re-designed.
-  Uses “php”
-  Easier navigation
-  Better
-   Documentation
-  NOMADS is
- renamed:
- NOAA _*National*_*...*

## Vision

-    “NOMADS is a distributed service oriented architecture, a system-of-systems integration based on using loosely coupled connections among independent systems to create a scalable, extensible, interoperable, reliable, and secure framework.”
-                                             ... reliable?

** ****What is service oriented architecture?**** **

## What is NOMADS? (con’t)

- A digital archive of NOAA’s operational weather models, and an “innovative data access philosophy to promote interoperable access across the geosciences” (BAMS, Rutledge et. al., 2006).
- A Pilot project at NCEP that advances integration of real time model data.
- NOMADS:  An integrator of common web services infrastructure to support the discovery, access and transport of data (NOAA GEO-IDE Document).

## NOMADS Goals

-   foster research within the geo-science
- communities (ocean, weather, and climate)
- to study multiple earth systems using
- collections of distributed data,

-   promote model evaluation and product development,

-   develop institutional partnerships via distributed open technologies.

-   provide distributed access to models and associated data,

*NOMADS Goals*

- _The NOAA Operational Model Archive and Distribution System_

## Goals

- To take advantage of internet technology opportunities.
- Improve efficiency and reduce costs by bridging the barriers between existing, independent “stove pipe” systems.
- Integrate the data management activities of NOAA projects.
- Individual components retain responsibility and authority within the context of a systematic set of principles.
- To Develop and adopt standards for metadata, data discovery and data transports, formats and protocols.

- Service oriented Goals (DMIT)

## The operational (reliability) problem

- To provide Operational Services where security, timeliness (time critical) and reliability are paramount.
- Operational public access services for public access to data, products and information services.
- Scientific services where efficient and flexible discovery and access to data sets is required.
- Commercial value-added services and user client applications.

## NOAA/NCEP Operational ftp services for model data

- Two operational centers (ftpprd... and tgftp...)
- Standard ftp servers
- Load balance, Fail over, State of the art hardware ($) and 24/7 support.
- A little difficult to navigate (file naming convention)
- Entire file (0.25GB) download necessary.
- Holdings not complete
- 	(0.5 degree GFS, NAM hourly, ensembles...?)
**Complete and “fast ftp” (Partial ftp transfers) for all data set holdings is imminent.**

## Slide 9

## What the user sees at the operational ftp site:

- Example of tgftp location for GFS model (first entry) files from June 15:

- Excerpt from the ftpprd inventory description:

- Inventory of File gfs.t00z.pgrbanl
- Model: 	GFS
- Cycle: 	00 UTC
- Forecast: 	0 HRS
- Number of Records: 	267
- Grid Identification : 	3
- Number 	Level/Layer 	Parameter 	Description
- 0001 	1000 	ISBL 	HGT 	1000 hPa isobaric level Geopotential height gpm]
- 0002 	975 	ISBL 	HGT 	975 hPa isobaric level Geopotential height [gpm]
- 0003 	950 	ISBL 	HGT 	950 hPa isobaric level Geopotential height [gpm]

- An Excerpt from the list of 500 files, note name and size:

- File: fh.0030_tl.press_gr.onedeg  	26562 KB  	06/15/2006
- File: fh.0030_tl.sflux 	               42981 KB 	06/15/2006

## Toward  Operational services

- We know how to do the hardware part.
- 	$ = load balance, fail over, 24/7, redundancy
- What about users usage of the applications, e.g., DAP and GDS and others
- Operationalise data flow to NCDC from NCEP.
- GRIB2 with jpeg packing increases CPU resources needed.
- Software to handle sub-seting and GRIB2
- GDS, OPeNDAP, and other applications need GRIB2 software stratagy.
- Implement with partial http transfers and index files.

## User Statistics

*User Statistics*

- Highest month:  4.3Tb    w/3.8 million downloads –
- 			    NCEP has ~1-5Tb /month

- NCDC
-  Only

- BAMS Paper

**Notes:**
NCEP has ~1-5Tb /month

## Real Time (NCEP) nomad3 server

- GDS/OPeN(DAP) DODS:  typically 250,000 queries/day from the GDS log (already /2).
- pdisp (“Great Displays”) 2694/day.
- http access_log  ~200,000 hits/day
- ftp2u (fast ftp index download) over 5/11 – 6/15
-    8,623 repackaged GRIB downloads/day.
- Need better ways of evaluating use for good health and for comparison of servers.

## Real Time (NCEP) NOMADS Server

- Users query files that are not present in tight loops.
- During the 12 hours [00Z-12Z] on June 1, of the 371 different users who queried the httpd server error_log, the top 7 users with the most queries are listed:
- _#queries_      _User_
- 1579    hawaii.edu
- 1616    abo.wanadoo.fr
- 1870    natpool.mwn.de
- 3293    accuweather.com
- 4039    saildocs.com
- 7864    hmg.inpg.fr
- 100465  labsolar.ufsc.br

- A solution:  Check log file (error_log)
- user access rate.  If the rate criteria (6/minute) is exceeded then place user’s IP address in IP tables to block access for that IP address for a period of time (10 minutes).
-   Placing users in a “penalty box” when they
- are repeatedly accessing the server in tight loops is the same as users placing a “sleep 600” command or wait 10 minutes in their unix script for loop.
- This represents a throttle that can be applied to other situations such as many GDS queries when one is needed.

## The NOMADS System Design

*The NOMADS System Design*

_**Multiple paths to format independent data access**_

**Notes:**
The next step in NOMADS is the availability of access by OGC standards for Web Mapping and Web Coverage Services.

## Search, Discovery, Access, and Analysis

*A metadata server, DIMES (Distributed Metadata Server) integrated with GDS to form MIDAS *(Kafatos, Yang, Zhao)* :*
**Metadata Integrated Data Analysis Server*** *
- Content consistency between data server and metadata server.
- Interactive metadata search and data access and analysis.
- Potential for more effective and efficient searching.
- Potential for better interfaces.
- More seamless transition from data search to data access.
- Uses XML to represent, store, retrieve and interoperate metadata with minimum semantic enforcement.
- Contains a metadata model, XML query engine, web-based prototype interface.
- Enables the application power of Grads and GDS server side data analysis.

## One can search by Time resolution (forecast time), Spatcial resolution, Search_Space (region), Search_Time (Cycle), and Text (variable and other Title text in the Metadata file.

## Slide 18

## 	After selection of the Time and Space Box, the user can generate an “sdfopen” URL 

- 	After selection of the Time and Space Box, the user can generate an “sdfopen” URL
- command including functionality, e.g,  time or space averaging, for further processing
- or generate the DODS URL and run GrADS client script and interactive commands.

## Future Plans

- Incorporate NOMADS functionality into CLASS (Comprehensive Large Array Stewardship system)
- Enhance the NCEP real time servers at NCDC and place in NCDC operations.
- Operationalise the data flow from NCEP to NCDC.
- Existing Operational NOAA servers can be enhanced with NOMADS service orientated architecture and administrators.
-  Support working prototypes for proof of concept and continued development toward improved services.