In this post, I would like to address some of the commonly faced issues while setting up SOLR to work with Sitecore. This post specifically targets Sitecore 8, but should be valid for some of the older versions
An index with the name “sitecore_master_index” have already been added.
The issue is that there is more than one index with the name “sitecore_master_index” being loaded on the sitecore application start.
Scenario 1 : While using SOLR, all the lucene index files are not disabled properly
Please make in your App_Config/Include folder , that only one of the two files is enabled (depends upon if you are using lucene or solr) Sitecore.ContentSearch.Lucene.Index.Master.config or Sitecore.ContentSearch.Solr.Index.Master.config
Scenario 2 : Custom patched config files
If you are using custom patched config files to add Index strategies or add computed fields to existing indexes, please make sure that your patches are being applied in correct order.
if you are unsure about how patching works, this link can get you started
Please comment below if you have questions or tweet me @sjain_hi