How do you update data in Solr 4?

Question

We need to update the index of Solr 4 but are getting some unexpected results. We run a C# program that uses SolrNet to do an AddRange(). In this process, we're adding new documents and also trying to update existing ones.

We're noticing that some records' fields get updated with the latest data, while others still show the old information. Should we be using the information indicated in the documentation?

The documentation indicates we can set an update="set|add|inc" on the field. If we'd like the existing record to be updated, should we use set? Also, when we delete a field, to have it removed, do we need to shut down Solr and restart? Or set null="true"?

Can you point us to some good information on doing updates to Solr data? Thank you.

Answer 1

The documenation reference that you list describes the parameters for Atomic Updates in Solr 4, which is currently not supported in SolrNet - see issue 199 for more details.

Until this support has been added to SolrNet, your only option for updating documents in the index is to resend the entire document (object in C#) with the required updated/deleted feilds set appropriately. Internally Solr will re-add the document to the index with the updated fields.

Also, when you are adding/updating documents in the index, these changes will not be visible to queries against the index until a commit has been issued. I would recommend using the CommitWithin option of AddParameters to allow Solr to handle this internally, this is described in detail in the SolrWiki - CommitWithin.