Provide Search API-based alternative to dblog

As discussed on Slack, I like the idea to log into Solr. So to build an alternative to elastic, logstash, kibana that is integrated in drupal and allows queries, facets, etc.

It might seem to be an advantage to implement it as common functionality in search_api to provide it as functionality for any backend.
But it adds overhead. For example the tracker. It creates additional database queries.

I would prefer a super lightwight and fast implementation of the LoggerInterface that directly writes to Solr using solarium, leveraging a connection defined in search_api_solr. That backend is based on the DocumentDatasource for foreign indexes.

And a predefined View could be used to display the log. Facets will work as well. Or custom queries written with Search API.

That could be packed and added as sub_module to search_api_solr, including the server config and the View. So the user just has to adjust the credentials and connection settings.

@mkalkbrenner: PoC of lighter, Solr-only logger implementation https://git.drupalcode.org/sandbox/valthebald-3476169
TL;DR; where possible, I followed dblog patterns, replacing database specifics with solarium queries

I like this approach.

What do you think of adding it as sub-module of search_api_solr?

I have some more suggestions, put I need to play with module first.

@mkalkbrenner sure, I will create a MR later today

valthebald → changed the visibility of the branch 3475570-logger to hidden.

valthebald → changed the visibility of the branch 3475570-solronly to hidden.

valthebald → closed merge request !47

@mkalkbrenner did you have a chance to check this?

I have created https://www.drupal.org/project/solrlog → as a separate project, to allow installations without patching search_api_solr