Can you try and query solr on the command line? Eg:
curl http://domain.com:8080/solr/collection1/update?commit=true -H "Content-Type: text/xml" --data-binary '<delete><query>*:*</query></delete>'
After running this query you should see something like
INFO: [phisch-dev] webapp=/solr path=/update params={wt=javabin&version=2} {deleteByQuery=*:* (-1428803632004857856)} 0 126
in solr logs (e.g. /var/log/tomcat7/catalina.2013-03-07.log).
I am using POST here, just to be sure GET/stream.body does not encode things in odd ways. I added the commit attribute so the delete query gets committed automatically.
Also, did you make any changes to your RequestHandler? Does it overwrite defaults or anything like that? Check your solrconfig.xml and search for /update. Mine contains (which is what ships with solr):
<requestHandler name="/update" class="solr.UpdateRequestHandler">
</requestHandler>
There should be no <lst name="defaults">
, <lst name="appends"
or <lst name="invariants">
BTW, changes to the Index are not visible until a new search is opened. What happens if you delete from the index and restart solr. Are the documents still there?
EDIT:
It happens to be a bug: https://issues.apache.org/jira/browse/SOLR-3432
Adding a _version_
field to the schema fixes this (thanks to Nyxynyx for this precision)