Throws Null Pointer Exception Even Query is Correct in solr

Team , I have creteria where i am passing more than 10 ids in Query like q=(ROWINDEX:(1 2 3 4 )) using solrJ . i had increased the Max Boolean clause = 10500 and i had increased the Max Header Size in tomcat also in sufficient amount .. But still its is throwing Null Pointer Excep

whethere solr 3.3 index file is compatable with solr 4.0

Team I have indexed my data with solr 3.3 version , As I need to use hierarchical facets features from solr 4.0 . Can I use the existing data with Solr 4.0 version or should need to re-index the data with new version? Thanks and Regards, S SYED ABDUL KATHER

Replication with different schema

Team, Is it possible to do replication with different Schema in solr ? If not how can i acheive this . Can any one can give an idea to do this advance thanks .. Thanks and Regards, S SYED ABDUL KATHER

Query regarding Lucene Indexing Method

Hi Team , Is there any article or site where I can learn about lucene index Method: how is it written and maintained? And one quick question : The Standard method that Lucene uses to handle Indexes, Is it apache package or Lucene has own Index writing Method? Does lucene use memory mapped f