How to recover from Solr deleted index files?

Question

When I delete solr's index files on disk, (found in /solr/data/index and solr/data/spellchecker), solr throws an exception whenever I try to make a request to it:

java.lang.RuntimeException: java.io.FileNotFoundException: no segments* file found in org.apache.lucene.store.NIOFSDirectory@/…/solr/data/index:

The only way I've found to recover from this is to “seed” the data directory with the index files from elsewhere. It doesn't really matter where it seems. Once I do this, I can run a query to reload the schema and regenerate the index. Is this how this is supposed to work? It seems like there should be a way to tell solr to regenerate those files from scratch. Maybe I'm just mistaken in my assumption that these files are not part of the application itself (kind of implied by the name “data”)?

Anytime

Answer 1

Solr will throw that exception at startup if the index directory exists but is empty. However if you delete the directory, Solr will create it and the empty segments files at startup.

Devine

This was my problem, just a note to others, I had to 1) Stop solr, 2) delete the directory, 3) start solr. When I had solr running and deleted the directory and tried to force an index it would still fail. Thanks for the help =] – Tojo

This is definitely the solution! Good catch :] – Phail

Answer 2

If you are using sunspot solr on rails, sunspot can reindex all the data from the database into solr. However, solr standalone would not know where to pull the data to reindex. You would need a backup of the data.

Disorientate

Answer 3

The problem may lie with the segments file if you delete the index . the files are physically deleted but are present in the ram or cache of the solr . Avoid deleting files directly from solr index files physically . use delete query to delete the index , doing this would alter the segments of the index and you will not have to restart the solr

regards

Rajat

Dunnock

Answer 4

Exception FileNotFoundException signals that an attempt to open the file denoted by a specified pathname has failed. So either your index is invalid or corrupted.

NIOFSDirectory class is used for reading and writing index files. The directory is created at the named location if it does not yet exist.

So you should probably:

1. Delete the index directory or restore data from backups.
2. Restart the server (or at least the reload the config).

Mundy