I've got a sizeable Solr server which is chewing a pile of disk. Whilst it is indexing a large amount of data, I'm wondering if there's any operation that will reduce the size of the index, by say dropping deleted-but-still-allocated data in a similar manner to a VACUUM FULL in PostgreSQL, or are the solr indexes kept fairly tidy, and my only option is to just allocate a pile more diskspace?
To my knowledge solr keeps its indexes fairly tidy. Are you deleting items from the index very often or only adding? If all you are doing is adding then you aren't even causing fragmentation... which is a good thing in your case since defragmenting a solr index (or optimizing it) causes the index to double in size while that process runs, which would probably be the opposite of what you're looking for. How much disk space are you chewing up right now?