I have CKAN 2.8.1 running with the Datastore and DataPusher extensions. They are all working well, and no errors appear in the logs.
I am trying to test CKAN by searching for a term which appears inside several resources (in different data sets). For example "electrophoresis" exists in 5 data sets. I can search for the various data sets, and through the data viewer, they show up in datastore_search.
However, if I use the primary search bar on CKAN and try that same term, nothing shows up. My understanding is that CKAN should return results for this.
If you want to index resource content in addition to the resource metadata (which is automatically indexed by CKAN) then take a look at ckanext-extractor, which does exactly that.
Disclaimer: I'm the author of ckanext-extractor.