Searching in Different Drupal websites

Question

I have 4 drupal websites different in Database and Files. I need to use drupal search for any website to get any content related in all others. Also, In article content type need to get related articles through all website.

Is Apache solar is best solution for that? and what's its limitation for this task?

Thanks

Answer 1

You need to read this

http://www.phase2technology.com/blog/exposing-external-content-to-drupals-search/

Do go through the comments as well.

It would be better to treat all 4 sites as different/external in case their DB's are different.