Hi, Salim,

Yes, sorry, there's a small weirdness in ConnectomeDB's web services interface. 
I thought I had fixed the HCP-customized pyxnat but I had pushed that 
workaround to the wrong branch. I've fixed that, and pulling the current tip of 
branch hcp-db should solve your problem.

Sorry for the confusion.

  - Kevin
________________________________
From: Salim Arslan [salim.ars...@yahoo.com]
Sent: Monday, November 10, 2014 5:27 AM
To: Archie, Kevin; hcp-users@humanconnectome.org
Subject: Re: [HCP-Users] Error: Server Refused Request (Code 34)

Hi Kevin (and all other readers),

Thank you very much for your detailed answer. I decided to go with the 
python-script option.

I was working through the tutorials you mentioned at 
https://wiki.humanconnectome.org/display/DataUse/Exploring+ConnectomeDB+with+Python
 . I have downloaded and installed all libraries and managed to open a working 
session. However I am unable to do the basics, such as listing the projects. 
For example when I run:

>>> cdb.select.projects().get()

I get the following errror:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File 
"/usr/local/lib/python2.7/dist-packages/pyxnat-0.9.5.3-py2.7.egg/pyxnat/core/resources.py",
 line 842, in get
    return [urllib.unquote(uri_last(eobj._uri)) for eobj in self]
  File 
"/usr/local/lib/python2.7/dist-packages/pyxnat-0.9.5.3-py2.7.egg/pyxnat/core/resources.py",
 line 663, in __iter__
    eid = urllib.unquote(res[id_header])
KeyError: 'ID'

However, when I run the following command and specify a project this time, 
there are no errors.

>>> q2 = cdb.select.project('HCP_Q2')

But when I want to see what is inside of this project object as described in 
the tutorial, I get nothing, but I should have got a list of subjects:

>>> [subject.label() for subject in q2.subjects()]
[ ]

I am running these on an Ubuntu 13.04 machine with Python 2.7.4. Am I doing 
something wrong?

Best wishes,

Salim

________________________________
From: "Archie, Kevin" <arch...@mir.wustl.edu>
To: Salim Arslan <salim.ars...@yahoo.com>; "hcp-users@humanconnectome.org" 
<hcp-users@humanconnectome.org>
Sent: Wednesday, November 5, 2014 5:02 PM
Subject: RE: [HCP-Users] Error: Server Refused Request (Code 34)

Salim,

I'm sorry you've been having trouble with the downloads. I don't know exactly 
what's going wrong, and I will suggest a workaround, but you might want to 
consider whether this is really what you want to do. The full 500 subject 
dataset is 18 TB zipped; I looked at the server logs of your successful 
downloads to get an estimate of the data rate between here and you, and that 
would be 16 days of continuous download to get everything (though you might 
want to check my arithmetic). Even if you're just getting a subset of the data 
that would still be days of downloading. Once you're done, you've got a bunch 
of zip files that you need to unpack, and you need somewhere to put 
it...Connectome in a Box 
(http://humanconnectome.org/data/connectome-in-a-box.html) really is a bargain 
if you want a substantial fraction of the data.

If I haven't sold you on the box, let's figure out how you can make this 
download work. I'm impressed by your script to keep the web session alive; as 
it turns out that won't make a difference--once the Aspera download is running, 
ConnectomeDB isn't involved anymore--but it was a good idea. The Aspera 
software does pretty well (in our experience) on the scale of hours but doesn't 
seem to hold up well at days. As you suggested, if you could partition the 
requests you could probably get better reliability, or at least lose less when 
something breaks.

I would look into making the requests from a Python script, using the tools 
described here: 
https://wiki.humanconnectome.org/display/DataUse/Exploring+ConnectomeDB+with+Python
 . There's a section "Accessing imaging data" that shows how to use the Aspera 
plugin to download data. This tutorial is a little out of date (was written 
after Q1 release and then patched for Q2), but with a bit of tweaking could be 
adapted to the 500 subject release. A single call to cdb.packages.download(...) 
will act like a single request from the webapp, so you probably want to 
partition the subjects and loop over the partitions, and maybe wrap it all up 
with some exception handling to automatically re-request any parts that fail.

If that sounds like a disaster, there's work underway to push a copy of all the 
HCP data to Amazon S3. It'll be probably a few weeks before this is done, and 
if you're downloading to anywhere outside of AWS it'll be slower (and therefore 
less reliable in aggregate) than Aspera but you could do your own partitioning 
and if you've already worked with S3, or if dealing with S3 seems less 
burdensome than getting pyxnat working, this might be attractive to you. Watch 
this mailing list for an announcement.

Good luck, and please don't hesitate to send mail to the list if you have 
questions or run into trouble.

 Kevin

________________________________
From: hcp-users-boun...@humanconnectome.org 
[hcp-users-boun...@humanconnectome.org] on behalf of Salim Arslan 
[salim.ars...@yahoo.com]
Sent: Wednesday, November 05, 2014 6:08 AM
To: hcp-users@humanconnectome.org
Subject: [HCP-Users] Error: Server Refused Request (Code 34)

Hi,

I have been trying to download the 500+ dataset, but due to its size I guess, 
the downloading process eventually gets frozen and when I try to re-establish 
the connection link I get this error: Server Refused Request (Code 34). On the 
Aspera web site the error is explained as "Unauthorized by external auth 
server"  (https://support.asperasoft.com/entries/22895528-fasp-Error-Codes) and 
it is not retryable. I have even used a script to periodically renew my session 
on the connectome database but it did not work.

My questions are:

1- Is there a way to download the 500 dataset without getting this error?
2- If not, can I create my own subsets and download them separately? Lets say 
divide the whole dataset into 5 100-subject subsets. Because I was able to 
download the 100 dataset without getting any errors.

Thanks in advance for any help!

Best wishes,
Salim



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