Type: New Feature
Affects Version/s: None
Fix Version/s: 4.9
It would be great if there was a clean simple approach to plugin custom analytics to Solr.
This ticket introduces the AnalyticsQuery class which makes this possible.
To add a custom analytic query you extend AnalyticsQuery and implement:
This method returns a custom DelegatingCollector which handles the collection of the analytics.
The DelegatingCollector.finish() method can be used to conveniently finish your analytics and place the output onto the response.
The AnalyticsQuery also has a nifty constructor that allows you to pass in a MergeStrategy (see
SOLR-5973). So, when you extend AnalyticsQuery you can pass in a custom MergeStrategy to handle merging of analytic output from the shards during a distributed search.
This design is a natural extension of the PostFilter framework. So you can plugin your AnalyticsQuery with a custom QParserPlugin, for example:
Just like PostFilters, AnalyticsQueries can be ordered using the "cost" parameter. This allows for analytic pipe-lining, where the result of one AnalyticsQuery can be pipe-lined to another AnalyticsQuery.