DAP4: Session and Request Header Support for netcdf-java

[DennisHeimbigner]

[This converts a E-Support question to an issue. Original question submitted by Nathan Potter of OPeNDAP.org (ndp at opendap.org)]

Some of our users are encountering performance issues while utilizing the netcdf-java library to access remote datasets using DAP4. hey are having two issues:

• The netcdf-java code lacks session support for DAP4 requests.
• The netcdf-java code lacks a way for the user to provide an arbitrary request header, such as an Authorization header, to be sent to the target service.

I had a look at the source code and I can see that there is no support for either of these things in the DAP4 code. The underlying Http machinery in HTTPFactory supports at least the session concept, but it is not utilized by the DAP4 code in HttpDSP.

I would like to add these features to the netcdf-java library, but I am seeing that I would need to do a fair bit of work in the library. And I would need to ask a number of questions of you and your team to accomplish this.

Mostly I think the challenge for me is to make the session stuff fit within conventions of the library's external file profile. Like where should the cookies for the session etc stored? What should file the permissions be?etc.

Is this a contribution you would be willing to accept?

If so would you (or someone) be available to help me sort out the conformity details?

[DennisHeimbigner]

Such a fix would be welcome, and I can certainly help with it. There used to be documentation of the HTTP system including authorization. It seems to have gotten lost somehow. Also, with what version of netcdf-java are you working? I need to make sure you are working with the latest version.

[DennisHeimbigner]

I found some of the old documentation. It may be helpful to this discussion (or not):

1. Authorization support Auth.html.txt
2. httpservices documentation httpservices.html.txt