Discussion page for the VOSpace 2.1 specification

This is a discussion page for the VOSpace-2.1 service specification.

Please edit this page directly to add comments or specification changes and additions.

Since this is a minor revision, all changes must be backwards compatible with the VOSpace-2.0 specification.

Changes and Enhancements for VOSpace 2.1

Parameter based sync transfer negotiation

This is a proposal to support the ability to perform a transfer negotiation by posting transfer parameters to the /sync endpoint. This would be functionally equivalent to posting the transfer XML document to the /sync endpoint. For example:

Parameter based POST:

curl -X POST -d "TARGET=vos://nvo.caltech!vospace/mydata1&DIRECTION=pullFromVoSpace&PROTOCOL=ivo://ivoa.net/vospace/core#httpget" "http://localhost:8000/sync"

Would be equivalent to:

curl -X POST -d @job.xml "http://localhost:8000/sync"

Where job.xml is a file containing:

<vos:transfer xmlns:vos="http://www.ivoa.net/xml/VOSpace/v2.1">
<vos:target>vos://nvo.caltech!vospace/mydata1</vos:target>
<vos:direction>pullFromVoSpace</vos:direction>
<vos:protocol>ivo://ivoa.net/vospace/core#httpget</vos:protocol>
</vos:transfer>

The motivation for adding this functionality is to allow the negotiation of a transfer to happen with a single URL without having a smart client or having to generate an XML document. This is convenient when referring to VOSpace nodes from web interfaces.

Add desired authentication method to transfer document

There isn't enough information in the transfer negotiation document to produce URLs to the data store correctly. The missing piece of information is authentication method they wish to use on the URLs. For example, if they wish to use userid/password to authenticate, the URLs must be pointed at a resource that will block and collect that information. If a cookie is to be used, the resource must not block. Authentication method options should include:

• userid/password basic authentication
• cookies
• x509 client certificate

This field should be optional in the transfer document.

Link Node documentation clarity

For the benefit of implementers, clarify the expected behaviour of the operations in Section 5 when the operation can pertain to LinkNodes.

Issues

Parameters for views in negotiated transfers?

One of the elements in a transfer document is the "view" element. If a value for this view is supplied (and it is not the Default View), VOSpace will respond in a way that is specific to that view for the target Node. However, one can imagine views that require input parameters in order to create a sensible response. For example: cutouts. For a cutout view to be implemented, there must be a way for users to provide cutout parameters. Version 2.0 of VOSpace does not allow for input parameters to be supplied to views in transfer negotiations.