Add serialization version flag to the Dataset element in the DMR part of a DAP4 Data Response.

[ndp-opendap]

Now that we have discovered and fixed an order of serialization bug we need to provide a mechanism for clients to identify the servers that are "patched".

Proposal:
Add a serialization attribute to the Dataset element on the DAP4 Data Response:

serialization="dap-4.0" 

like this:

<Dataset 
    xmlns="http://xml.opendap.org/ns/DAP/4.0#" 
    xml:base="http://test.opendap.org:8080/opendap/NSIDC/ATL01_20201221111151_04882305_002_01.h5.dmr" 
    dapVersion="4.0" 
    dmrVersion="1.0" 
    dap:serialization="4.0" 
    name="ATL01_20201221111151_04882305_002_01.h5">

(edited)

Let's modify/discuss/refine this here, before we try to fix it.

@Mikejmnez , @jgallagher59701 , @dh-opendap , @hannahilea

(We tried to use the dmrVersion attribute but the semantics didn't work so we are going to try and fix it, again)

[jgallagher59701]

We should probably do this.

[jgallagher59701]

Suggestion: Lets make the value of the 'serialization' Dataset XML attribute a number or text, not both.

[ndp-opendap]

then I think we should be specific:

dap:serialization="4.0"

And this is slipping we need to do this ASAP

[ndp-opendap]

@jgallagher59701 - @kevinbeam says this breaks compatibility with the java-netcdf.

Can we prioritize this issue? It's breaking things.

[hannahilea]

Let's discuss at standup tomorrow?

[ndp-opendap]

Looks like @kevinbeam going to hack/modify NetCDF-java to address this dmrVersion business. He's going to hack it to allow dmrVersion="2.0". That's good for them - they need to move forward, but it's bad for DAP4 because it further enshrines this error into intractable permanence.

[Mikejmnez]

From the Client API's perspective, it is less about what the flag is, and more about being able to identify that a data response was produced by a Hyrax server (and subsequently which version of the Hyrax server).

Even simply adding the details of the hyrax build (similar to the way a DMR++ includes the libdap/bes/olfs etc versions) would do.

Here is my comment
OPENDAP/dap4-specification#42 (comment)