External File Field in Apache Solr

问题:

I've been trying to use ExternalFileField in ApacheSolr for external scoring.

I'm using the example config. Basically I want to set scores for items using their ids.

I set the fieldType idRankFile and field idRank in schema.xml:

<fieldType name="idRankFile" keyField="id" defVal="0" stored="true" indexed="true" class="solr.ExternalFileField" valType="pfloat" />
<field name="idRank" type="idRankFile" indexed="true" stored="true" />

And made a file called external_idRank in /solr/example/solr/data with the following content:

F8V7067-APL-KIT = 1.0
IW-02 = 10.0
9885A004 = 100.0
SOLR1000 = 1000.0

(This assigns idRank values for various ids)

Now I run the following query :

http://localhost:8983/solr/select/?indent=on&q=car%20power%20adapter%20_val_:%22product(idRank,1)%22&fl=name,id

This should basically return the results in order of their idRanks. However, it does not.

Any ideas?

回答1:

Alright, so I had the same problem. This is what I did:

1. Create a file:
   solr_home/PROJECT/multicore/core1/data/external_popularProducts.txt

   The file should contain values like this:
   uniqueID_in_core=count

   Example:
   873728721=19
842728342=20

2. Update schema.xml, add this under <types> </types>
<fieldType name="popularProductsFile" keyField="key" defVal="0" stored="true" indexed="true" class="solr.ExternalFileField" valType="float" />

   Here, key is the column name for the primaryID of solr core.
   Add this under <fields></fields>
<field name="popularProducts" type="popularProductsFile" indexed="true" stored="true" />

3. Reload the core. I am using solr4.3 which has a bug. When I try to reload any core,the solrcloud node goes down. SOLR-4805: SolrCloud - RELOAD on collections or cores leaves collection offline and unusable till restart . So, I had to restart my solrcloud nodes.

4. Query: http://SOLR_NODE:8983/solr/core1/select?q=ipad&sort=popularProducts desc

Note:
Most of the blogs written about ExternalFileField are not completely accurate. So just refer to the original documentation:

1. http://lucene.apache.org/solr/4_3_1/solr-core/org/apache/solr/schema/ExternalFileField.html .
2. http://docs.lucidworks.com/display/solr/Working+with+External+Files+and+Processes

Please improve this answer if you find any issues with it.