Search Service Applications return different Crawl results on identical Content Sources

Question

I have a weird problem with Full Crawls returning only partial results. I have a production setup and an identical test setup, with Sharepoint Server Search (Sharepoint 2010).

When i run a Full Crawl on "Local Sharepoint Sites" in the production environment, the result contains only about 1300 searchable items. Some custom Content Types doesn't seem to get indexed.

When i backup-restore the Site Collection to my test environment (to have identical content), the search service application on the test environment returns about 4500 results, and I can see the custom Content Types in search (When issuing a search like: ContentType:"CustomDocType", the search results are as expected). I've checked that User Policy allows the Content Access account Full Read on the web app in both environments, and both Scopes and Crawl Rules are configured the same way.

There are no error indications in the Crawl history logs, it only contains about 1300-1400 entries.

I'm really at a loss here, any suggestions are welcome

Answer 1

Can you check that the Content Sources (Search Administration) are also defined exactly the same on both environments? Also, the order of the rules can affect results as well so even the slightest variation can cause what you are seeing, depending on the rule.

One thing to try is to purge the search results and force a fresh crawl on both farms as it is possible that one farm has some kruft left in it.