Test with Couchdb 2.2 or later (2.3.1)

[mcjaeger]

after the dependencies updates have been performed, we need to make test with couchdb 2.2 - in the ideal case on an updated productive test.

[bs-matil]

I would love to see couchdb upgraded so I'm looking for the missing parts. This Issue rnewson/couchdb-lucene#259 (comment) states that couchdb 2.x works just fine and only the query endpoint changes are there any other problems known here?

[bs-matil]

While understanding the issue with all of this I found the following:

• currently couchdb lucene is used with an ektorp wrapper https://github.com/ldriscoll/ektorplucene which is utterly unmaintained and will not work with newer ektorp versions.
• all we actually need is a new (maybe self written) provider which wraps the lucene index schema.
• The index settings are currently anyways stored as plaintext for example e.g. https://github.com/eclipse/sw360/blob/a1a92a975df0773644972a119fdf1852ef4227b9/backend/src-common/src/main/java/org/eclipse/sw360/datahandler/db/ComponentSearchHandler.java#L36-L80
• The only thing we have to redo here is the wrapping of the LuceneDocument
• The heavy lifting will happen if we have to rebuild the complete query path and how the query results are converted back to thrift objects. Which seems to be the most complex issue here.

Still I only try to unterstand this issue and scratched only the surface. Any help is appreciated.

Ideas:

• within this refactoring one should try to move the documents or the indices to configuration files which may be static but can be set externally instead of embedding them all within the code. There seems a lot of duplicated code in this mechanism.

Acceptance Criteria (only as a WIP for my understandment)

• Remove dependency https://github.com/ldriscoll/ektorplucene
  currently I favor to reuse the old classes from the existing dependency of ektorplucene but completely override anything regards the real connection handling. My be creating a custom LuceneAwreCouchDB...
• Add a new query library for Rewrite the connection handling for lucene within the existing wrapper project and reuse the object converter for the resulting thrift objects and ektorp
• Evaluate if this can be achieved by replacing also couchdb-lucene and embedding solr instead. (to expensive right now)
• (optional? own ticket?) Move index description files for couchdb-lucene out of the code into configurations (*.js)

[mcjaeger]

for now, sw360 runs with couchdb 2.X:

https://github.com/sw360/sw360vagrant/wiki

and also the support for couchdb 3 is under testing:

sw360/sw360vagrant#38