Ruby script to check which MARC records are missing from a Solr index.

marcsolrchecker.rb

require 'rubygems'

# Be sure to have the latest version of rubygems and run:
# sudo gem install rsolr
# sudo gem install marc

require 'rsolr'
require 'marc'

# Set the following three vars to whatever applies locally.
solr = RSolr.connect :url=>'http://localhost:8080/solr'
marc_path = '/path/to/marc/files/'
skipped_marc_out = '/path/to/skipped_marc_out.mrc'

marc_out = MARC::Writer.new(skipped_marc_out)
Dir.open(marc_path).each do | file |
  MARC::ForgivingReader.new(open("#{marc_path}#{file}")).each do | record |
    ctrl = record['001'].value
    response = solr.select :q=>"id:#{ctrl}"
    unless response['response']['numFound'] > 0
      marc_out.write(record)
    end
  end
end
marc_out.close