lists of servers used by VSO (for firewalls/proxies)
Joe Hourcle
I'm relaying this question, in part so that Igor or Alisdair can post a
response to the person who posted it on Facebook, as I'm one of those
strange people who avoids that website.
> Hello people of VSO and thanks a lot for your hard work!.
> I have a question related with the network connection in order to get
> data from the IDL interface. I'm working with a proxy-internet
> connection and at this moment I can't get any data from any provider
> associated with VSO. I would like to know, if I need SDO, STEREO,
> RHESSI and GONG data, which ftp or http addresses I need to add to the
> proxy exceptions?
> Thanks a lot for your time.
The way that VSO is built, it can be changed without our knowing about it.
Basically, the 'vso_search' and 'vso_get' commands both make calls to a
web service, which is found by calling 'vso_server':
IDL> print, vso_server()
http://sdac.virtualsolar.org/cgi-bin/vsoi_tabdelim
It seems static, but it's actually a list that works by failover -- if one
is down, it'll then attempt to use the next one in the list. The current
list is two machines:
proxies = [ $
'http://sdac.virtualsolar.org/cgi-bin/vsoi_tabdelim' $
,'http://vso.tuc.noao.edu/cgi-bin/drms_test/vsoi_tabdelim' $
]
As part of the 'vso_get' call, the data provider can respond with any
server. Right now, there's only one that does, and it's more predictable
as (right now) it's only affected by the 'site' keyword, but we hope to
move to automatic selection of the closest SDO mirror:
IDL> aia = vso_search( inst='aia', wave=304, pix=4096, /latest )
Records Returned : JSOC : 1/1
IDL> status = vso_get(aia, site='nso', /nodownload)
IDL> print, status.url
http://vso.tuc.noao.edu/cgi-bin/drms_test/drms_export.cgi?series=aia__lev1;record=304_1088812832-1088812832
IDL> status = vso_get(aia, site='sao', /nodownload)
IDL> print, status.url
http://kurasuta.cfa.harvard.edu/cgi-bin/VSO/prod/drms_export.cgi?series=aia__lev1;record=304_1088812832-1088812832
IDL> status = vso_get(aia, site='rob', /nodownload)
IDL> print, status.url
http://sdodata.oma.be/vsoprovider/drms_export.cgi?series=aia__lev1;record=304_1088812832-1088812832
IDL> status = vso_get(aia, site='uclan', /nodownload)
IDL> print, status.url
http://vso.sdo.uclan.ac.uk/cgi-bin/drms_export.cgi?series=aia__lev1;record=304_1088812832-1088812832
For the other data providers, we can use this same method to get a list of
servers that their requests resolve to, but it's also possible for there
to be changes in the future and/or for them to include logic to shunt off
larger requests to alternate servers, or similar. Right now, I don't know
of any that do that, so the lists for the missions asked about would be:
VSO (in general for any of this to work):
http://sdac.virtualsolar.org/
http://vso.tuc.noao.edu/
SDO / DRMS (any one of ...) :
http://vso.tuc.noao.edu/
http://sdo4.nascom.nasa.gov/
http://kurasuta.cfa.harvard.edu/
http://sdodata.oma.be/
http://vso.sdo.uclan.ac.uk/
SDO (AIA NRT images):
http://sdo1.nascom.nasa.gov/
STEREO:
http://stereo-ssc.nascom.nasa.gov/
RHESSI:
http://hesperia.gsfc.nasa.gov/
GONG (data at NSO; LOS_magnetic_field + merged LOS_velocity)
ftp://gong2.nso.edu/
GONG (data at SHA; LOS_magnetic_field, LOS_velocity, intensity, equivalent_width)
... um ...
Okay, now SHA's a special case, as when the data provider was written,
then didn't give direct URLs to their data, and we haven't gone back to
change it. They had previously handled all data requests asynconously, so
to get data from SHA, you have to pass an email address to vso_get:
IDL> sha_gong = vso_search( '2003-01-01', source='gong', physobs='intensity' )
Records Returned : SHA : 10/10
IDL> status = vso_get( sha_gong, email='joseph....@example.org' )
% VSO::GETDATA: SHA: Request Accepted. Processing may take up to 2 business days
% VSO_GET: Sorry, no valid URL addresses associated with these data records
% VSO_GET: (this may not be an error if you sent an e-mail address for data staging)
... and then wait for an e-mail. (and the 2 days is a worst case scenario
if they have to load tapes, I've typically gotten responses back within
the hour)
-Joe
(ps, and Igor, Alisdair, or whoever posts this to facebook ... you might
also want to mention the VSO-IDL mailing list, and/or the general vso help
e-mail address)
Joseph B. Gurman
----
"I love deadlines. I love the whooshing sound they make as they go by."
- Douglas Adams, 1952 - 2001
Joseph B. Gurman, Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt MD 20771 USA