Ferret talk - Sep 2006 - Error with :create => true and existing index

I implemented a "reindex" command which simply creates an IndexWriter
with :create => true for a prexisting index. 

The "reindexing" seems to start out ok, with several thousand docs
added, then Ferret throws an exception:

IO Error occured: couldn''t rename file "index\_0.tmp" to
"index\_0.cfs":
<File exists>

I guess that _0.cfs is held open by an IndexReader, so the :create is
failing to delete it and hence the rename is failing.

Kind Regards

Neville

On 9/22/06, Neville Burnell <Neville.Burnell at bmsoft.com.au>
wrote:
> I implemented a "reindex" command which simply creates an
IndexWriter
> with :create => true for a prexisting index.
>
> The "reindexing" seems to start out ok, with several thousand
docs
> added, then Ferret throws an exception:
>
> IO Error occured: couldn''t rename file "index\_0.tmp" to
"index\_0.cfs":
> <File exists>
>
> I guess that _0.cfs is held open by an IndexReader, so the :create is
> failing to delete it and hence the rename is failing.
>
> Kind Regards
>
> Neville
>
Hi Neville,

Probably a good guess. That is why you need to close your IndexReader
when you finish with it.

I''m not sure if you are asking for a confirmation that this was the
problem or looking for a solution. Let me know if closing all
IndexReaders doesn''t fix the error.

Cheers,
Dave

> I''m not sure if you are asking for a confirmation that this was
the
> problem or looking for a solution.
I guess I am looking for a solution to rebuilding the index while
readers are active.

For the time being I could simply delete all docs, then add all docs.  

Would a IndexWriter.delete_all be possible?

Kind Regards

Neville

On 9/23/06, Neville Burnell <Neville.Burnell at bmsoft.com.au>
wrote:
> > I''m not sure if you are asking for a confirmation that this
was the
> > problem or looking for a solution.
>
> I guess I am looking for a solution to rebuilding the index while
> readers are active.
>
> For the time being I could simply delete all docs, then add all docs.
>
> Would a IndexWriter.delete_all be possible?
>
> Kind Regards
>
> Neville
Hi Neville,

You could do it like this:

    reader.max_doc.times {|i| reader.delete(i)}

That will delete all documents. Make sure you close your IndexWriter
before doing this though as the IndexReader will try and obtain locks
on the index for the deletions.

Alternatively you could use a rotating index directory. When you
rebuild, rebuild in a new directory. Then when you have finished
rebuilding, re-open the IndexReaders on the new directory.

Both solutions should work equally well.

Cheers,
Dave