[Go-essp-tech] Status of Gateway 2.0 (another use case)

Thu Dec 15 06:52:05 MST 2011

Hi, Estanislao -- 
Please see my comments inline.

On Dec 15, 2011, at 5:47 AM, Estanislao Gonzalez wrote:

> Hi Jennifer,
> 
> I'm still not sure how is Lucas change in the API going to help you Jennifer. But perhaps it would help me to fully understand your requirement as well as your use of wget when using the FTP  protocol.
> 
> I presume what you want is to crawl the archive and get file from a specific directory structure?
> Maybe it would be better if you just describe briefly the procedure you've been using for getting the CMIP3 data so we can see what could be done for CMIP5.
> 
> How did you find out which data was interesting?
COLA scientists ask for a specific scenario/realm/frequency/variable they need for their research. Our CMIP3 collection is a shared resource of about 4Tb of data. For CMIP5, we are working with an estimate of 4-5 times that data volume to meet our needs. It's hard to say at this point whether that will be enough. 

> How did you find out which files were required to be downloaded?
For CMIP3, we often referred to http://www-pcmdi.llnl.gov/ipcc/data_status_tables.htm to see what was available. 

The new version of this chart for CMIP5, http://cmip-pcmdi.llnl.gov/cmip5/esg_tables/transpose_esg_static_table.html, is also useful. An improvement I'd like to see on this page: the numbers inside the blue boxes that show how many runs there are for a particular experiment/model should be a link to a list of those runs that has all the necessary components from the Data Reference Synatax so that I can go directly to the URL for that data set. For example, 
the BCC-CSM1.1 model shows 45 runs for the decadal1960 experiment. I would like to click on that 45 and get a list of the 45 URLs for those runs, like this:
http://pcmdi3.llnl.gov/esgcet/dataset/cmip5.output1.BCC.bcc-csm1-1.decadal1960.day.land.day.r1i1p1.html
http://pcmdi3.llnl.gov/esgcet/dataset/cmip5.output1.BCC.bcc-csm1-1.decadal1960.day.land.day.r2i1p1.html
...

> How did you tell wget to download those files?
For example: wget -nH --retr-symlinks -r -A nc ftp://username@ftp-esg.ucllnl.org/picntrl/atm/mo/tas -o log.tas
This would populate a local directory ./picntrl/atm/mo/tas with all the models and ensemble members in the proper subdirectory. If I wanted to update with newer versions or models that had been added, I simply ran the same 1-line wget command again. This is what I refer to as 'elegant.'

> We might have already some way of achieving what you want, if we knew exactly what that is.
Wouldn't that be wonderful? I am hopeful that the P2P will simplify the elaborate and flawed workflow I have cobbled together to navigate the current system.
I have a list of desired experiment/realm/frequency/MIP_table/variables for which I need to grab all available models/ensembles. Is that not enough to describe my needs? 

> 
> I guess my proposal of issuing:
> bash <(wget http://p2pnode/wget?experiment=decadal1960&realm=atmos&time_frequency=month&variable=clt -qO - | grep -v HadCM3)
Yes, this would likely achieve the same result as the '&model=!name' that Luca implemented. However, I believe the documentation says that there is a limit of 1000 to the number of wgets that p2pnode will put into a single search request, so I don't want to populate my precious 1000 results with wgets that I'm going to grep out afterwards. 

--Jennifer

> 
> was not acceptable to you. But I still don't know exactly why. 
> It would really help to know what you meant by "elegant use of wget".
> 
> Thanks,
> Estani
> 
> 
> Am 14.12.2011 18:44, schrieb Cinquini, Luca (3880):
>> 
>> So Jennifer, would having the capability of doing negative searches (model=!CCSM), and generate the corresponding wget scripts, help you ?
>> thanks, Luca
>> 
>> On Dec 14, 2011, at 10:38 AM, Jennifer Adams wrote:
>> 
>>> Well, after working from the client side to get CMIP3 and CMIP5 data, I can say that wget is a fine tool to rely on at the core of the workflow. Unfortunately, the step up in complexity from CMIP3 to CMIP5 and the switch from FTP to HTTP trashed the elegant use of wget. No amount of customized wrapper software, browser interfaces, or pre-packaged tools like DML fixes that problem. 
>>> 
>>> At the moment, the burden on the user is embarrassingly high. It's so easy to suggest that the user should "filter to remove what is not required" from a downloaded script, but the actual pratice of doing that in a timely and automated and distributed way is NOT simple! And if the solution to my problem of filling in the gaps in my incomplete collection is to go back to clicking in my browser and do the whole thing over again but make my filters smarter by looking for what's already been acquired or what has a new version number … this is unacceptable. The filtering must be a server-side responsibility and the interface must be accessible by automated scripts. Make it so! 
>>> 
>>> By the way, the version number is a piece of metadata that is not in the downloaded files or the gateway's search criteria. It appears in the wget script as part of the path in the file's http location, but the path is not preserved after the wget is complete, so it is effectively lost after the download is done. I guess the file's date stamp would be the only way to know if the version number of the data file in question has been changed, but I'm not going to write that check into my filtering scripts. 
>>> 
>>> --Jennifer
>>> 
>>> 
>>> --
>>> Jennifer M. Adams
>>> IGES/COLA
>>> 4041 Powder Mill Road, Suite 302
>>> Calverton, MD 20705
>>> jma at cola.iges.org
>>> 
>>> 
>>> 
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>> 
>> 
>> 
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> 
> -- 
> Estanislao Gonzalez
> 
> Max-Planck-Institut für Meteorologie (MPI-M)
> Deutsches Klimarechenzentrum (DKRZ) - German Climate Computing Centre
> Room 108 - Bundesstrasse 45a, D-20146 Hamburg, Germany
> 
> Phone:   +49 (40) 46 00 94-126
> E-Mail:  gonzalez at dkrz.de 
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--
Jennifer M. Adams
IGES/COLA
4041 Powder Mill Road, Suite 302
Calverton, MD 20705
jma at cola.iges.org

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