Solr HTTP error: Not Found (404) using Solarium

Question

I am using Solarium to access Solr from PHP. When I perform a normal select query using Solarium everything works fine.

Problem: When I attempt to do a MoreLikeThis query, I get the following error when trying to execute the query. What went wrong, and how can it be fixed?

Solr HTTP error: Not Found (404)

Location:
/home/mysite/public_html/application/libraries/Solarium/Result.php on line 98

PHP Code

$client = new Solarium_Client($config);

$query = $client->createMoreLikeThis()
                ->setQuery('id:' . $product_id)
                ->setMltFields('title, description')
                ->setMinimumDocumentFrequency(1)
                ->setMinimumTermFrequency(1)
                ->setInterestingTerms('details')
                ->setMatchInclude(false)
                ->setRows(10);
$resultset = $client->select($query);

I probed into the Solarium_Client_Response_Object at /solarium/Client.php and found the response received to be

Solarium_Client_Response Object
(
    [_headers:protected] => Array
        (
            [0] => HTTP/1.1 404 Not Found
            [1] => Server: Apache-Coyote/1.1
            [2] => Content-Type: text/html;charset=utf-8
            [3] => Content-Length: 979
            [4] => Date: Mon, 27 Aug 2012 12:03:42 GMT
            [5] => Connection: close
        )

    [_body:protected] => 
    [_statusCode:protected] => 404
    [_statusMessage:protected] => Not Found
)

Answer 1

You need to have the morelikethis handler configured in Solr. You probably have a select handler, so the standard select works. But for the morelikethis querytype you need to have another handler configured.

For more info see: http://wiki.apache.org/solr/MoreLikeThisHandler